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-rw-r--r--kernel/bpf/verifier.c2
-rw-r--r--kernel/cgroup.c31
-rw-r--r--kernel/cpu.c1162
-rw-r--r--kernel/cpuset.c71
-rw-r--r--kernel/debug/kdb/kdb_bp.c4
-rw-r--r--kernel/events/core.c466
-rw-r--r--kernel/events/uprobes.c1
-rw-r--r--kernel/futex.c139
-rw-r--r--kernel/irq/Kconfig4
-rw-r--r--kernel/irq/Makefile1
-rw-r--r--kernel/irq/chip.c4
-rw-r--r--kernel/irq/handle.c6
-rw-r--r--kernel/irq/internals.h7
-rw-r--r--kernel/irq/ipi.c326
-rw-r--r--kernel/irq/irqdesc.c21
-rw-r--r--kernel/irq/irqdomain.c11
-rw-r--r--kernel/irq/manage.c17
-rw-r--r--kernel/irq/proc.c2
-rw-r--r--kernel/irq/spurious.c4
-rw-r--r--kernel/kallsyms.c42
-rw-r--r--kernel/kexec_core.c8
-rw-r--r--kernel/kexec_file.c8
-rw-r--r--kernel/latencytop.c14
-rw-r--r--kernel/locking/lockdep.c189
-rw-r--r--kernel/locking/mcs_spinlock.h8
-rw-r--r--kernel/locking/mutex.c5
-rw-r--r--kernel/locking/qspinlock.c7
-rw-r--r--kernel/locking/qspinlock_paravirt.h21
-rw-r--r--kernel/locking/qspinlock_stat.h16
-rw-r--r--kernel/memremap.c48
-rw-r--r--kernel/module.c124
-rw-r--r--kernel/power/hibernate.c17
-rw-r--r--kernel/power/process.c12
-rw-r--r--kernel/power/suspend.c6
-rw-r--r--kernel/profile.c1
-rw-r--r--kernel/rcu/rcutorture.c20
-rw-r--r--kernel/rcu/tiny_plugin.h15
-rw-r--r--kernel/rcu/tree.c238
-rw-r--r--kernel/rcu/tree.h54
-rw-r--r--kernel/rcu/tree_plugin.h59
-rw-r--r--kernel/rcu/update.c1
-rw-r--r--kernel/resource.c154
-rw-r--r--kernel/sched/Makefile3
-rw-r--r--kernel/sched/clock.c5
-rw-r--r--kernel/sched/core.c511
-rw-r--r--kernel/sched/cpufreq.c37
-rw-r--r--kernel/sched/cputime.c53
-rw-r--r--kernel/sched/deadline.c66
-rw-r--r--kernel/sched/debug.c415
-rw-r--r--kernel/sched/fair.c323
-rw-r--r--kernel/sched/idle.c9
-rw-r--r--kernel/sched/rt.c116
-rw-r--r--kernel/sched/sched.h149
-rw-r--r--kernel/sched/stats.h8
-rw-r--r--kernel/sched/swait.c123
-rw-r--r--kernel/smp.c10
-rw-r--r--kernel/smpboot.c6
-rw-r--r--kernel/smpboot.h6
-rw-r--r--kernel/softirq.c4
-rw-r--r--kernel/sysctl.c13
-rw-r--r--kernel/time/clocksource.c52
-rw-r--r--kernel/time/jiffies.c2
-rw-r--r--kernel/time/posix-cpu-timers.c52
-rw-r--r--kernel/time/tick-sched.c175
-rw-r--r--kernel/time/tick-sched.h1
-rw-r--r--kernel/time/timekeeping.c286
-rw-r--r--kernel/trace/ftrace.c36
-rw-r--r--kernel/trace/power-traces.c1
-rw-r--r--kernel/trace/trace_events.c17
-rw-r--r--kernel/trace/trace_events_filter.c13
-rw-r--r--kernel/trace/trace_kprobe.c19
-rw-r--r--kernel/trace/trace_stack.c6
-rw-r--r--kernel/trace/trace_syscalls.c16
-rw-r--r--kernel/tsacct.c54
-rw-r--r--kernel/workqueue.c77
75 files changed, 4300 insertions, 1710 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d1d3e8f57de9..2e7f7ab739e4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2082,7 +2082,7 @@ static void adjust_branches(struct bpf_prog *prog, int pos, int delta)
/* adjust offset of jmps if necessary */
if (i < pos && i + insn->off + 1 > pos)
insn->off += delta;
- else if (i > pos && i + insn->off + 1 < pos)
+ else if (i > pos + delta && i + insn->off + 1 <= pos + delta)
insn->off -= delta;
}
}
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c03a640ef6da..d27904c193da 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -58,6 +58,7 @@
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/atomic.h>
+#include <linux/cpuset.h>
#include <net/sock.h>
/*
@@ -2739,6 +2740,7 @@ out_unlock_rcu:
out_unlock_threadgroup:
percpu_up_write(&cgroup_threadgroup_rwsem);
cgroup_kn_unlock(of->kn);
+ cpuset_post_attach_flush();
return ret ?: nbytes;
}
@@ -4655,14 +4657,15 @@ static void css_free_work_fn(struct work_struct *work)
if (ss) {
/* css free path */
+ struct cgroup_subsys_state *parent = css->parent;
int id = css->id;
- if (css->parent)
- css_put(css->parent);
-
ss->css_free(css);
cgroup_idr_remove(&ss->css_idr, id);
cgroup_put(cgrp);
+
+ if (parent)
+ css_put(parent);
} else {
/* cgroup free path */
atomic_dec(&cgrp->root->nr_cgrps);
@@ -4758,6 +4761,7 @@ static void init_and_link_css(struct cgroup_subsys_state *css,
INIT_LIST_HEAD(&css->sibling);
INIT_LIST_HEAD(&css->children);
css->serial_nr = css_serial_nr_next++;
+ atomic_set(&css->online_cnt, 0);
if (cgroup_parent(cgrp)) {
css->parent = cgroup_css(cgroup_parent(cgrp), ss);
@@ -4780,6 +4784,10 @@ static int online_css(struct cgroup_subsys_state *css)
if (!ret) {
css->flags |= CSS_ONLINE;
rcu_assign_pointer(css->cgroup->subsys[ss->id], css);
+
+ atomic_inc(&css->online_cnt);
+ if (css->parent)
+ atomic_inc(&css->parent->online_cnt);
}
return ret;
}
@@ -5017,10 +5025,15 @@ static void css_killed_work_fn(struct work_struct *work)
container_of(work, struct cgroup_subsys_state, destroy_work);
mutex_lock(&cgroup_mutex);
- offline_css(css);
- mutex_unlock(&cgroup_mutex);
- css_put(css);
+ do {
+ offline_css(css);
+ css_put(css);
+ /* @css can't go away while we're holding cgroup_mutex */
+ css = css->parent;
+ } while (css && atomic_dec_and_test(&css->online_cnt));
+
+ mutex_unlock(&cgroup_mutex);
}
/* css kill confirmation processing requires process context, bounce */
@@ -5029,8 +5042,10 @@ static void css_killed_ref_fn(struct percpu_ref *ref)
struct cgroup_subsys_state *css =
container_of(ref, struct cgroup_subsys_state, refcnt);
- INIT_WORK(&css->destroy_work, css_killed_work_fn);
- queue_work(cgroup_destroy_wq, &css->destroy_work);
+ if (atomic_dec_and_test(&css->online_cnt)) {
+ INIT_WORK(&css->destroy_work, css_killed_work_fn);
+ queue_work(cgroup_destroy_wq, &css->destroy_work);
+ }
}
/**
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5b9d39633ce9..6ea42e8da861 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -22,13 +22,88 @@
#include <linux/lockdep.h>
#include <linux/tick.h>
#include <linux/irq.h>
+#include <linux/smpboot.h>
+
#include <trace/events/power.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/cpuhp.h>
#include "smpboot.h"
+/**
+ * cpuhp_cpu_state - Per cpu hotplug state storage
+ * @state: The current cpu state
+ * @target: The target state
+ * @thread: Pointer to the hotplug thread
+ * @should_run: Thread should execute
+ * @cb_stat: The state for a single callback (install/uninstall)
+ * @cb: Single callback function (install/uninstall)
+ * @result: Result of the operation
+ * @done: Signal completion to the issuer of the task
+ */
+struct cpuhp_cpu_state {
+ enum cpuhp_state state;
+ enum cpuhp_state target;
+#ifdef CONFIG_SMP
+ struct task_struct *thread;
+ bool should_run;
+ enum cpuhp_state cb_state;
+ int (*cb)(unsigned int cpu);
+ int result;
+ struct completion done;
+#endif
+};
+
+static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
+
+/**
+ * cpuhp_step - Hotplug state machine step
+ * @name: Name of the step
+ * @startup: Startup function of the step
+ * @teardown: Teardown function of the step
+ * @skip_onerr: Do not invoke the functions on error rollback
+ * Will go away once the notifiers are gone
+ * @cant_stop: Bringup/teardown can't be stopped at this step
+ */
+struct cpuhp_step {
+ const char *name;
+ int (*startup)(unsigned int cpu);
+ int (*teardown)(unsigned int cpu);
+ bool skip_onerr;
+ bool cant_stop;
+};
+
+static DEFINE_MUTEX(cpuhp_state_mutex);
+static struct cpuhp_step cpuhp_bp_states[];
+static struct cpuhp_step cpuhp_ap_states[];
+
+/**
+ * cpuhp_invoke_callback _ Invoke the callbacks for a given state
+ * @cpu: The cpu for which the callback should be invoked
+ * @step: The step in the state machine
+ * @cb: The callback function to invoke
+ *
+ * Called from cpu hotplug and from the state register machinery
+ */
+static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step,
+ int (*cb)(unsigned int))
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int ret = 0;
+
+ if (cb) {
+ trace_cpuhp_enter(cpu, st->target, step, cb);
+ ret = cb(cpu);
+ trace_cpuhp_exit(cpu, st->state, step, ret);
+ }
+ return ret;
+}
+
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
+bool cpuhp_tasks_frozen;
+EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
/*
* The following two APIs (cpu_maps_update_begin/done) must be used when
@@ -207,31 +282,281 @@ int __register_cpu_notifier(struct notifier_block *nb)
return raw_notifier_chain_register(&cpu_chain, nb);
}
-static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
int *nr_calls)
{
+ unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
+ void *hcpu = (void *)(long)cpu;
+
int ret;
- ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+ ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
nr_calls);
return notifier_to_errno(ret);
}
-static int cpu_notify(unsigned long val, void *v)
+static int cpu_notify(unsigned long val, unsigned int cpu)
{
- return __cpu_notify(val, v, -1, NULL);
+ return __cpu_notify(val, cpu, -1, NULL);
}
-#ifdef CONFIG_HOTPLUG_CPU
+/* Notifier wrappers for transitioning to state machine */
+static int notify_prepare(unsigned int cpu)
+{
+ int nr_calls = 0;
+ int ret;
+
+ ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
+ if (ret) {
+ nr_calls--;
+ printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
+ __func__, cpu);
+ __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
+ }
+ return ret;
+}
+
+static int notify_online(unsigned int cpu)
+{
+ cpu_notify(CPU_ONLINE, cpu);
+ return 0;
+}
+
+static int notify_starting(unsigned int cpu)
+{
+ cpu_notify(CPU_STARTING, cpu);
+ return 0;
+}
+
+static int bringup_wait_for_ap(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+ wait_for_completion(&st->done);
+ return st->result;
+}
+
+static int bringup_cpu(unsigned int cpu)
+{
+ struct task_struct *idle = idle_thread_get(cpu);
+ int ret;
+
+ /* Arch-specific enabling code. */
+ ret = __cpu_up(cpu, idle);
+ if (ret) {
+ cpu_notify(CPU_UP_CANCELED, cpu);
+ return ret;
+ }
+ ret = bringup_wait_for_ap(cpu);
+ BUG_ON(!cpu_online(cpu));
+ return ret;
+}
+
+/*
+ * Hotplug state machine related functions
+ */
+static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st,
+ struct cpuhp_step *steps)
+{
+ for (st->state++; st->state < st->target; st->state++) {
+ struct cpuhp_step *step = steps + st->state;
+
+ if (!step->skip_onerr)
+ cpuhp_invoke_callback(cpu, st->state, step->startup);
+ }
+}
+
+static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
+ struct cpuhp_step *steps, enum cpuhp_state target)
+{
+ enum cpuhp_state prev_state = st->state;
+ int ret = 0;
+
+ for (; st->state > target; st->state--) {
+ struct cpuhp_step *step = steps + st->state;
+
+ ret = cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ if (ret) {
+ st->target = prev_state;
+ undo_cpu_down(cpu, st, steps);
+ break;
+ }
+ }
+ return ret;
+}
+
+static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st,
+ struct cpuhp_step *steps)
+{
+ for (st->state--; st->state > st->target; st->state--) {
+ struct cpuhp_step *step = steps + st->state;
+
+ if (!step->skip_onerr)
+ cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ }
+}
+
+static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
+ struct cpuhp_step *steps, enum cpuhp_state target)
+{
+ enum cpuhp_state prev_state = st->state;
+ int ret = 0;
+
+ while (st->state < target) {
+ struct cpuhp_step *step;
+
+ st->state++;
+ step = steps + st->state;
+ ret = cpuhp_invoke_callback(cpu, st->state, step->startup);
+ if (ret) {
+ st->target = prev_state;
+ undo_cpu_up(cpu, st, steps);
+ break;
+ }
+ }
+ return ret;
+}
+
+/*
+ * The cpu hotplug threads manage the bringup and teardown of the cpus
+ */
+static void cpuhp_create(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+ init_completion(&st->done);
+}
+
+static int cpuhp_should_run(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+
+ return st->should_run;
+}
+
+/* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */
+static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+ enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU);
+
+ return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target);
+}
+
+/* Execute the online startup callbacks. Used to be CPU_ONLINE */
+static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+ return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target);
+}
+
+/*
+ * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke
+ * callbacks when a state gets [un]installed at runtime.
+ */
+static void cpuhp_thread_fun(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+ int ret = 0;
+
+ /*
+ * Paired with the mb() in cpuhp_kick_ap_work and
+ * cpuhp_invoke_ap_callback, so the work set is consistent visible.
+ */
+ smp_mb();
+ if (!st->should_run)
+ return;
+
+ st->should_run = false;
+
+ /* Single callback invocation for [un]install ? */
+ if (st->cb) {
+ if (st->cb_state < CPUHP_AP_ONLINE) {
+ local_irq_disable();
+ ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+ local_irq_enable();
+ } else {
+ ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+ }
+ } else {
+ /* Cannot happen .... */
+ BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
+
+ /* Regular hotplug work */
+ if (st->state < st->target)
+ ret = cpuhp_ap_online(cpu, st);
+ else if (st->state > st->target)
+ ret = cpuhp_ap_offline(cpu, st);
+ }
+ st->result = ret;
+ complete(&st->done);
+}
-static void cpu_notify_nofail(unsigned long val, void *v)
+/* Invoke a single callback on a remote cpu */
+static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state,
+ int (*cb)(unsigned int))
{
- BUG_ON(cpu_notify(val, v));
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+
+ if (!cpu_online(cpu))
+ return 0;
+
+ st->cb_state = state;
+ st->cb = cb;
+ /*
+ * Make sure the above stores are visible before should_run becomes
+ * true. Paired with the mb() above in cpuhp_thread_fun()
+ */
+ smp_mb();
+ st->should_run = true;
+ wake_up_process(st->thread);
+ wait_for_completion(&st->done);
+ return st->result;
}
+
+/* Regular hotplug invocation of the AP hotplug thread */
+static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st)
+{
+ st->result = 0;
+ st->cb = NULL;
+ /*
+ * Make sure the above stores are visible before should_run becomes
+ * true. Paired with the mb() above in cpuhp_thread_fun()
+ */
+ smp_mb();
+ st->should_run = true;
+ wake_up_process(st->thread);
+}
+
+static int cpuhp_kick_ap_work(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ enum cpuhp_state state = st->state;
+
+ trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work);
+ __cpuhp_kick_ap_work(st);
+ wait_for_completion(&st->done);
+ trace_cpuhp_exit(cpu, st->state, state, st->result);
+ return st->result;
+}
+
+static struct smp_hotplug_thread cpuhp_threads = {
+ .store = &cpuhp_state.thread,
+ .create = &cpuhp_create,
+ .thread_should_run = cpuhp_should_run,
+ .thread_fn = cpuhp_thread_fun,
+ .thread_comm = "cpuhp/%u",
+ .selfparking = true,
+};
+
+void __init cpuhp_threads_init(void)
+{
+ BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads));
+ kthread_unpark(this_cpu_read(cpuhp_state.thread));
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
EXPORT_SYMBOL(register_cpu_notifier);
EXPORT_SYMBOL(__register_cpu_notifier);
-
void unregister_cpu_notifier(struct notifier_block *nb)
{
cpu_maps_update_begin();
@@ -311,57 +636,60 @@ static inline void check_for_tasks(int dead_cpu)
read_unlock(&tasklist_lock);
}
-struct take_cpu_down_param {
- unsigned long mod;
- void *hcpu;
-};
+static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
+{
+ BUG_ON(cpu_notify(val, cpu));
+}
+
+static int notify_down_prepare(unsigned int cpu)
+{
+ int err, nr_calls = 0;
+
+ err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
+ if (err) {
+ nr_calls--;
+ __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL);
+ pr_warn("%s: attempt to take down CPU %u failed\n",
+ __func__, cpu);
+ }
+ return err;
+}
+
+static int notify_dying(unsigned int cpu)
+{
+ cpu_notify(CPU_DYING, cpu);
+ return 0;
+}
/* Take this CPU down. */
static int take_cpu_down(void *_param)
{
- struct take_cpu_down_param *param = _param;
- int err;
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+ enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE);
+ int err, cpu = smp_processor_id();
/* Ensure this CPU doesn't handle any more interrupts. */
err = __cpu_disable();
if (err < 0)
return err;
- cpu_notify(CPU_DYING | param->mod, param->hcpu);
+ /* Invoke the former CPU_DYING callbacks */
+ for (; st->state > target; st->state--) {
+ struct cpuhp_step *step = cpuhp_ap_states + st->state;
+
+ cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ }
/* Give up timekeeping duties */
tick_handover_do_timer();
/* Park the stopper thread */
- stop_machine_park((long)param->hcpu);
+ stop_machine_park(cpu);
return 0;
}
-/* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu, int tasks_frozen)
+static int takedown_cpu(unsigned int cpu)
{
- int err, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
- struct take_cpu_down_param tcd_param = {
- .mod = mod,
- .hcpu = hcpu,
- };
-
- if (num_online_cpus() == 1)
- return -EBUSY;
-
- if (!cpu_online(cpu))
- return -EINVAL;
-
- cpu_hotplug_begin();
-
- err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
- if (err) {
- nr_calls--;
- __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
- pr_warn("%s: attempt to take down CPU %u failed\n",
- __func__, cpu);
- goto out_release;
- }
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int err;
/*
* By now we've cleared cpu_active_mask, wait for all preempt-disabled
@@ -378,6 +706,8 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
else
synchronize_rcu();
+ /* Park the smpboot threads */
+ kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
smpboot_park_threads(cpu);
/*
@@ -389,12 +719,12 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
/*
* So now all preempt/rcu users must observe !cpu_active().
*/
- err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
+ err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
- cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
+ cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
irq_unlock_sparse();
- goto out_release;
+ return err;
}
BUG_ON(cpu_online(cpu));
@@ -405,10 +735,8 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
*
* Wait for the stop thread to go away.
*/
- while (!per_cpu(cpu_dead_idle, cpu))
- cpu_relax();
- smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
- per_cpu(cpu_dead_idle, cpu) = false;
+ wait_for_completion(&st->done);
+ BUG_ON(st->state != CPUHP_AP_IDLE_DEAD);
/* Interrupts are moved away from the dying cpu, reenable alloc/free */
irq_unlock_sparse();
@@ -417,20 +745,104 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
/* This actually kills the CPU. */
__cpu_die(cpu);
- /* CPU is completely dead: tell everyone. Too late to complain. */
tick_cleanup_dead_cpu(cpu);
- cpu_notify_nofail(CPU_DEAD | mod, hcpu);
+ return 0;
+}
+static int notify_dead(unsigned int cpu)
+{
+ cpu_notify_nofail(CPU_DEAD, cpu);
check_for_tasks(cpu);
+ return 0;
+}
-out_release:
+static void cpuhp_complete_idle_dead(void *arg)
+{
+ struct cpuhp_cpu_state *st = arg;
+
+ complete(&st->done);
+}
+
+void cpuhp_report_idle_dead(void)
+{
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+
+ BUG_ON(st->state != CPUHP_AP_OFFLINE);
+ rcu_report_dead(smp_processor_id());
+ st->state = CPUHP_AP_IDLE_DEAD;
+ /*
+ * We cannot call complete after rcu_report_dead() so we delegate it
+ * to an online cpu.
+ */
+ smp_call_function_single(cpumask_first(cpu_online_mask),
+ cpuhp_complete_idle_dead, st, 0);
+}
+
+#else
+#define notify_down_prepare NULL
+#define takedown_cpu NULL
+#define notify_dead NULL
+#define notify_dying NULL
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* Requires cpu_add_remove_lock to be held */
+static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
+ enum cpuhp_state target)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int prev_state, ret = 0;
+ bool hasdied = false;
+
+ if (num_online_cpus() == 1)
+ return -EBUSY;
+
+ if (!cpu_present(cpu))
+ return -EINVAL;
+
+ cpu_hotplug_begin();
+
+ cpuhp_tasks_frozen = tasks_frozen;
+
+ prev_state = st->state;
+ st->target = target;
+ /*
+ * If the current CPU state is in the range of the AP hotplug thread,
+ * then we need to kick the thread.
+ */
+ if (st->state > CPUHP_TEARDOWN_CPU) {
+ ret = cpuhp_kick_ap_work(cpu);
+ /*
+ * The AP side has done the error rollback already. Just
+ * return the error code..
+ */
+ if (ret)
+ goto out;
+
+ /*
+ * We might have stopped still in the range of the AP hotplug
+ * thread. Nothing to do anymore.
+ */
+ if (st->state > CPUHP_TEARDOWN_CPU)
+ goto out;
+ }
+ /*
+ * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need
+ * to do the further cleanups.
+ */
+ ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target);
+
+ hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
+out:
cpu_hotplug_done();
- if (!err)
- cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
- return err;
+ /* This post dead nonsense must die */
+ if (!ret && hasdied)
+ cpu_notify_nofail(CPU_POST_DEAD, cpu);
+ return ret;
}
-int cpu_down(unsigned int cpu)
+static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
{
int err;
@@ -441,100 +853,131 @@ int cpu_down(unsigned int cpu)
goto out;
}
- err = _cpu_down(cpu, 0);
+ err = _cpu_down(cpu, 0, target);
out:
cpu_maps_update_done();
return err;
}
+int cpu_down(unsigned int cpu)
+{
+ return do_cpu_down(cpu, CPUHP_OFFLINE);
+}
EXPORT_SYMBOL(cpu_down);
#endif /*CONFIG_HOTPLUG_CPU*/
-/*
- * Unpark per-CPU smpboot kthreads at CPU-online time.
+/**
+ * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * @cpu: cpu that just started
+ *
+ * This function calls the cpu_chain notifiers with CPU_STARTING.
+ * It must be called by the arch code on the new cpu, before the new cpu
+ * enables interrupts and before the "boot" cpu returns from __cpu_up().
*/
-static int smpboot_thread_call(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+void notify_cpu_starting(unsigned int cpu)
{
- int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE);
- case CPU_DOWN_FAILED:
- case CPU_ONLINE:
- smpboot_unpark_threads(cpu);
- break;
+ while (st->state < target) {
+ struct cpuhp_step *step;
- default:
- break;
+ st->state++;
+ step = cpuhp_ap_states + st->state;
+ cpuhp_invoke_callback(cpu, st->state, step->startup);
}
-
- return NOTIFY_OK;
}
-static struct notifier_block smpboot_thread_notifier = {
- .notifier_call = smpboot_thread_call,
- .priority = CPU_PRI_SMPBOOT,
-};
-
-void smpboot_thread_init(void)
+/*
+ * Called from the idle task. We need to set active here, so we can kick off
+ * the stopper thread and unpark the smpboot threads. If the target state is
+ * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the
+ * cpu further.
+ */
+void cpuhp_online_idle(enum cpuhp_state state)
{
- register_cpu_notifier(&smpboot_thread_notifier);
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+ unsigned int cpu = smp_processor_id();
+
+ /* Happens for the boot cpu */
+ if (state != CPUHP_AP_ONLINE_IDLE)
+ return;
+
+ st->state = CPUHP_AP_ONLINE_IDLE;
+
+ /* The cpu is marked online, set it active now */
+ set_cpu_active(cpu, true);
+ /* Unpark the stopper thread and the hotplug thread of this cpu */
+ stop_machine_unpark(cpu);
+ kthread_unpark(st->thread);
+
+ /* Should we go further up ? */
+ if (st->target > CPUHP_AP_ONLINE_IDLE)
+ __cpuhp_kick_ap_work(st);
+ else
+ complete(&st->done);
}
/* Requires cpu_add_remove_lock to be held */
-static int _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
{
- int ret, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
struct task_struct *idle;
+ int ret = 0;
cpu_hotplug_begin();
- if (cpu_online(cpu) || !cpu_present(cpu)) {
+ if (!cpu_present(cpu)) {
ret = -EINVAL;
goto out;
}
- idle = idle_thread_get(cpu);
- if (IS_ERR(idle)) {
- ret = PTR_ERR(idle);
- goto out;
- }
-
- ret = smpboot_create_threads(cpu);
- if (ret)
+ /*
+ * The caller of do_cpu_up might have raced with another
+ * caller. Ignore it for now.
+ */
+ if (st->state >= target)
goto out;
- ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
- if (ret) {
- nr_calls--;
- pr_warn("%s: attempt to bring up CPU %u failed\n",
- __func__, cpu);
- goto out_notify;
+ if (st->state == CPUHP_OFFLINE) {
+ /* Let it fail before we try to bring the cpu up */
+ idle = idle_thread_get(cpu);
+ if (IS_ERR(idle)) {
+ ret = PTR_ERR(idle);
+ goto out;
+ }
}
- /* Arch-specific enabling code. */
- ret = __cpu_up(cpu, idle);
-
- if (ret != 0)
- goto out_notify;
- BUG_ON(!cpu_online(cpu));
+ cpuhp_tasks_frozen = tasks_frozen;
- /* Now call notifier in preparation. */
- cpu_notify(CPU_ONLINE | mod, hcpu);
+ st->target = target;
+ /*
+ * If the current CPU state is in the range of the AP hotplug thread,
+ * then we need to kick the thread once more.
+ */
+ if (st->state > CPUHP_BRINGUP_CPU) {
+ ret = cpuhp_kick_ap_work(cpu);
+ /*
+ * The AP side has done the error rollback already. Just
+ * return the error code..
+ */
+ if (ret)
+ goto out;
+ }
-out_notify:
- if (ret != 0)
- __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+ /*
+ * Try to reach the target state. We max out on the BP at
+ * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is
+ * responsible for bringing it up to the target state.
+ */
+ target = min((int)target, CPUHP_BRINGUP_CPU);
+ ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target);
out:
cpu_hotplug_done();
-
return ret;
}
-int cpu_up(unsigned int cpu)
+static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
{
int err = 0;
@@ -558,12 +1001,16 @@ int cpu_up(unsigned int cpu)
goto out;
}
- err = _cpu_up(cpu, 0);
-
+ err = _cpu_up(cpu, 0, target);
out:
cpu_maps_update_done();
return err;
}
+
+int cpu_up(unsigned int cpu)
+{
+ return do_cpu_up(cpu, CPUHP_ONLINE);
+}
EXPORT_SYMBOL_GPL(cpu_up);
#ifdef CONFIG_PM_SLEEP_SMP
@@ -586,7 +1033,7 @@ int disable_nonboot_cpus(void)
if (cpu == first_cpu)
continue;
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
- error = _cpu_down(cpu, 1);
+ error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
@@ -636,7 +1083,7 @@ void enable_nonboot_cpus(void)
for_each_cpu(cpu, frozen_cpus) {
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
- error = _cpu_up(cpu, 1);
+ error = _cpu_up(cpu, 1, CPUHP_ONLINE);
trace_suspend_resume(TPS("CPU_ON"), cpu, false);
if (!error) {
pr_info("CPU%d is up\n", cpu);
@@ -709,26 +1156,463 @@ core_initcall(cpu_hotplug_pm_sync_init);
#endif /* CONFIG_PM_SLEEP_SMP */
+#endif /* CONFIG_SMP */
+
+/* Boot processor state steps */
+static struct cpuhp_step cpuhp_bp_states[] = {
+ [CPUHP_OFFLINE] = {
+ .name = "offline",
+ .startup = NULL,
+ .teardown = NULL,
+ },
+#ifdef CONFIG_SMP
+ [CPUHP_CREATE_THREADS]= {
+ .name = "threads:create",
+ .startup = smpboot_create_threads,
+ .teardown = NULL,
+ .cant_stop = true,
+ },
+ /*
+ * Preparatory and dead notifiers. Will be replaced once the notifiers
+ * are converted to states.
+ */
+ [CPUHP_NOTIFY_PREPARE] = {
+ .name = "notify:prepare",
+ .startup = notify_prepare,
+ .teardown = notify_dead,
+ .skip_onerr = true,
+ .cant_stop = true,
+ },
+ /* Kicks the plugged cpu into life */
+ [CPUHP_BRINGUP_CPU] = {
+ .name = "cpu:bringup",
+ .startup = bringup_cpu,
+ .teardown = NULL,
+ .cant_stop = true,
+ },
+ /*
+ * Handled on controll processor until the plugged processor manages
+ * this itself.
+ */
+ [CPUHP_TEARDOWN_CPU] = {
+ .name = "cpu:teardown",
+ .startup = NULL,
+ .teardown = takedown_cpu,
+ .cant_stop = true,
+ },
+#endif
+};
+
+/* Application processor state steps */
+static struct cpuhp_step cpuhp_ap_states[] = {
+#ifdef CONFIG_SMP
+ /* Final state before CPU kills itself */
+ [CPUHP_AP_IDLE_DEAD] = {
+ .name = "idle:dead",
+ },
+ /*
+ * Last state before CPU enters the idle loop to die. Transient state
+ * for synchronization.
+ */
+ [CPUHP_AP_OFFLINE] = {
+ .name = "ap:offline",
+ .cant_stop = true,
+ },
+ /*
+ * Low level startup/teardown notifiers. Run with interrupts
+ * disabled. Will be removed once the notifiers are converted to
+ * states.
+ */
+ [CPUHP_AP_NOTIFY_STARTING] = {
+ .name = "notify:starting",
+ .startup = notify_starting,
+ .teardown = notify_dying,
+ .skip_onerr = true,
+ .cant_stop = true,
+ },
+ /* Entry state on starting. Interrupts enabled from here on. Transient
+ * state for synchronsization */
+ [CPUHP_AP_ONLINE] = {
+ .name = "ap:online",
+ },
+ /* Handle smpboot threads park/unpark */
+ [CPUHP_AP_SMPBOOT_THREADS] = {
+ .name = "smpboot:threads",
+ .startup = smpboot_unpark_threads,
+ .teardown = NULL,
+ },
+ /*
+ * Online/down_prepare notifiers. Will be removed once the notifiers
+ * are converted to states.
+ */
+ [CPUHP_AP_NOTIFY_ONLINE] = {
+ .name = "notify:online",
+ .startup = notify_online,
+ .teardown = notify_down_prepare,
+ },
+#endif
+ /*
+ * The dynamically registered state space is here
+ */
+
+ /* CPU is fully up and running. */
+ [CPUHP_ONLINE] = {
+ .name = "online",
+ .startup = NULL,
+ .teardown = NULL,
+ },
+};
+
+/* Sanity check for callbacks */
+static int cpuhp_cb_check(enum cpuhp_state state)
+{
+ if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE)
+ return -EINVAL;
+ return 0;
+}
+
+static bool cpuhp_is_ap_state(enum cpuhp_state state)
+{
+ /*
+ * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
+ * purposes as that state is handled explicitely in cpu_down.
+ */
+ return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
+}
+
+static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
+{
+ struct cpuhp_step *sp;
+
+ sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
+ return sp + state;
+}
+
+static void cpuhp_store_callbacks(enum cpuhp_state state,
+ const char *name,
+ int (*startup)(unsigned int cpu),
+ int (*teardown)(unsigned int cpu))
+{
+ /* (Un)Install the callbacks for further cpu hotplug operations */
+ struct cpuhp_step *sp;
+
+ mutex_lock(&cpuhp_state_mutex);
+ sp = cpuhp_get_step(state);
+ sp->startup = startup;
+ sp->teardown = teardown;
+ sp->name = name;
+ mutex_unlock(&cpuhp_state_mutex);
+}
+
+static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
+{
+ return cpuhp_get_step(state)->teardown;
+}
+
+/*
+ * Call the startup/teardown function for a step either on the AP or
+ * on the current CPU.
+ */
+static int cpuhp_issue_call(int cpu, enum cpuhp_state state,
+ int (*cb)(unsigned int), bool bringup)
+{
+ int ret;
+
+ if (!cb)
+ return 0;
+ /*
+ * The non AP bound callbacks can fail on bringup. On teardown
+ * e.g. module removal we crash for now.
+ */
+#ifdef CONFIG_SMP
+ if (cpuhp_is_ap_state(state))
+ ret = cpuhp_invoke_ap_callback(cpu, state, cb);
+ else
+ ret = cpuhp_invoke_callback(cpu, state, cb);
+#else
+ ret = cpuhp_invoke_callback(cpu, state, cb);
+#endif
+ BUG_ON(ret && !bringup);
+ return ret;
+}
+
+/*
+ * Called from __cpuhp_setup_state on a recoverable failure.
+ *
+ * Note: The teardown callbacks for rollback are not allowed to fail!
+ */
+static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state,
+ int (*teardown)(unsigned int cpu))
+{
+ int cpu;
+
+ if (!teardown)
+ return;
+
+ /* Roll back the already executed steps on the other cpus */
+ for_each_present_cpu(cpu) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int cpustate = st->state;
+
+ if (cpu >= failedcpu)
+ break;
+
+ /* Did we invoke the startup call on that cpu ? */
+ if (cpustate >= state)
+ cpuhp_issue_call(cpu, state, teardown, false);
+ }
+}
+
+/*
+ * Returns a free for dynamic slot assignment of the Online state. The states
+ * are protected by the cpuhp_slot_states mutex and an empty slot is identified
+ * by having no name assigned.
+ */
+static int cpuhp_reserve_state(enum cpuhp_state state)
+{
+ enum cpuhp_state i;
+
+ mutex_lock(&cpuhp_state_mutex);
+ for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
+ if (cpuhp_ap_states[i].name)
+ continue;
+
+ cpuhp_ap_states[i].name = "Reserved";
+ mutex_unlock(&cpuhp_state_mutex);
+ return i;
+ }
+ mutex_unlock(&cpuhp_state_mutex);
+ WARN(1, "No more dynamic states available for CPU hotplug\n");
+ return -ENOSPC;
+}
+
/**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
- * @cpu: cpu that just started
+ * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state
+ * @state: The state to setup
+ * @invoke: If true, the startup function is invoked for cpus where
+ * cpu state >= @state
+ * @startup: startup callback function
+ * @teardown: teardown callback function
*
- * This function calls the cpu_chain notifiers with CPU_STARTING.
- * It must be called by the arch code on the new cpu, before the new cpu
- * enables interrupts and before the "boot" cpu returns from __cpu_up().
+ * Returns 0 if successful, otherwise a proper error code
*/
-void notify_cpu_starting(unsigned int cpu)
+int __cpuhp_setup_state(enum cpuhp_state state,
+ const char *name, bool invoke,
+ int (*startup)(unsigned int cpu),
+ int (*teardown)(unsigned int cpu))
{
- unsigned long val = CPU_STARTING;
+ int cpu, ret = 0;
+ int dyn_state = 0;
-#ifdef CONFIG_PM_SLEEP_SMP
- if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
- val = CPU_STARTING_FROZEN;
-#endif /* CONFIG_PM_SLEEP_SMP */
- cpu_notify(val, (void *)(long)cpu);
+ if (cpuhp_cb_check(state) || !name)
+ return -EINVAL;
+
+ get_online_cpus();
+
+ /* currently assignments for the ONLINE state are possible */
+ if (state == CPUHP_AP_ONLINE_DYN) {
+ dyn_state = 1;
+ ret = cpuhp_reserve_state(state);
+ if (ret < 0)
+ goto out;
+ state = ret;
+ }
+
+ cpuhp_store_callbacks(state, name, startup, teardown);
+
+ if (!invoke || !startup)
+ goto out;
+
+ /*
+ * Try to call the startup callback for each present cpu
+ * depending on the hotplug state of the cpu.
+ */
+ for_each_present_cpu(cpu) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int cpustate = st->state;
+
+ if (cpustate < state)
+ continue;
+
+ ret = cpuhp_issue_call(cpu, state, startup, true);
+ if (ret) {
+ cpuhp_rollback_install(cpu, state, teardown);
+ cpuhp_store_callbacks(state, NULL, NULL, NULL);
+ goto out;
+ }
+ }
+out:
+ put_online_cpus();
+ if (!ret && dyn_state)
+ return state;
+ return ret;
}
+EXPORT_SYMBOL(__cpuhp_setup_state);
-#endif /* CONFIG_SMP */
+/**
+ * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state
+ * @state: The state to remove
+ * @invoke: If true, the teardown function is invoked for cpus where
+ * cpu state >= @state
+ *
+ * The teardown callback is currently not allowed to fail. Think
+ * about module removal!
+ */
+void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
+{
+ int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state);
+ int cpu;
+
+ BUG_ON(cpuhp_cb_check(state));
+
+ get_online_cpus();
+
+ if (!invoke || !teardown)
+ goto remove;
+
+ /*
+ * Call the teardown callback for each present cpu depending
+ * on the hotplug state of the cpu. This function is not
+ * allowed to fail currently!
+ */
+ for_each_present_cpu(cpu) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int cpustate = st->state;
+
+ if (cpustate >= state)
+ cpuhp_issue_call(cpu, state, teardown, false);
+ }
+remove:
+ cpuhp_store_callbacks(state, NULL, NULL, NULL);
+ put_online_cpus();
+}
+EXPORT_SYMBOL(__cpuhp_remove_state);
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
+static ssize_t show_cpuhp_state(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+
+ return sprintf(buf, "%d\n", st->state);
+}
+static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL);
+
+static ssize_t write_cpuhp_target(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+ struct cpuhp_step *sp;
+ int target, ret;
+
+ ret = kstrtoint(buf, 10, &target);
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL
+ if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE)
+ return -EINVAL;
+#else
+ if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE)
+ return -EINVAL;
+#endif
+
+ ret = lock_device_hotplug_sysfs();
+ if (ret)
+ return ret;
+
+ mutex_lock(&cpuhp_state_mutex);
+ sp = cpuhp_get_step(target);
+ ret = !sp->name || sp->cant_stop ? -EINVAL : 0;
+ mutex_unlock(&cpuhp_state_mutex);
+ if (ret)
+ return ret;
+
+ if (st->state < target)
+ ret = do_cpu_up(dev->id, target);
+ else
+ ret = do_cpu_down(dev->id, target);
+
+ unlock_device_hotplug();
+ return ret ? ret : count;
+}
+
+static ssize_t show_cpuhp_target(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
+
+ return sprintf(buf, "%d\n", st->target);
+}
+static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target);
+
+static struct attribute *cpuhp_cpu_attrs[] = {
+ &dev_attr_state.attr,
+ &dev_attr_target.attr,
+ NULL
+};
+
+static struct attribute_group cpuhp_cpu_attr_group = {
+ .attrs = cpuhp_cpu_attrs,
+ .name = "hotplug",
+ NULL
+};
+
+static ssize_t show_cpuhp_states(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t cur, res = 0;
+ int i;
+
+ mutex_lock(&cpuhp_state_mutex);
+ for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) {
+ struct cpuhp_step *sp = cpuhp_get_step(i);
+
+ if (sp->name) {
+ cur = sprintf(buf, "%3d: %s\n", i, sp->name);
+ buf += cur;
+ res += cur;
+ }
+ }
+ mutex_unlock(&cpuhp_state_mutex);
+ return res;
+}
+static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL);
+
+static struct attribute *cpuhp_cpu_root_attrs[] = {
+ &dev_attr_states.attr,
+ NULL
+};
+
+static struct attribute_group cpuhp_cpu_root_attr_group = {
+ .attrs = cpuhp_cpu_root_attrs,
+ .name = "hotplug",
+ NULL
+};
+
+static int __init cpuhp_sysfs_init(void)
+{
+ int cpu, ret;
+
+ ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
+ &cpuhp_cpu_root_attr_group);
+ if (ret)
+ return ret;
+
+ for_each_possible_cpu(cpu) {
+ struct device *dev = get_cpu_device(cpu);
+
+ if (!dev)
+ continue;
+ ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+device_initcall(cpuhp_sysfs_init);
+#endif
/*
* cpu_bit_bitmap[] is a special, "compressed" data structure that
@@ -789,3 +1673,25 @@ void init_cpu_online(const struct cpumask *src)
{
cpumask_copy(&__cpu_online_mask, src);
}
+
+/*
+ * Activate the first processor.
+ */
+void __init boot_cpu_init(void)
+{
+ int cpu = smp_processor_id();
+
+ /* Mark the boot cpu "present", "online" etc for SMP and UP case */
+ set_cpu_online(cpu, true);
+ set_cpu_active(cpu, true);
+ set_cpu_present(cpu, true);
+ set_cpu_possible(cpu, true);
+}
+
+/*
+ * Must be called _AFTER_ setting up the per_cpu areas
+ */
+void __init boot_cpu_state_init(void)
+{
+ per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
+}
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 3e945fcd8179..41989ab4db57 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -287,6 +287,8 @@ static struct cpuset top_cpuset = {
static DEFINE_MUTEX(cpuset_mutex);
static DEFINE_SPINLOCK(callback_lock);
+static struct workqueue_struct *cpuset_migrate_mm_wq;
+
/*
* CPU / memory hotplug is handled asynchronously.
*/
@@ -972,31 +974,51 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
}
/*
- * cpuset_migrate_mm
- *
- * Migrate memory region from one set of nodes to another.
- *
- * Temporarilly set tasks mems_allowed to target nodes of migration,
- * so that the migration code can allocate pages on these nodes.
- *
- * While the mm_struct we are migrating is typically from some
- * other task, the task_struct mems_allowed that we are hacking
- * is for our current task, which must allocate new pages for that
- * migrating memory region.
+ * Migrate memory region from one set of nodes to another. This is
+ * performed asynchronously as it can be called from process migration path
+ * holding locks involved in process management. All mm migrations are
+ * performed in the queued order and can be waited for by flushing
+ * cpuset_migrate_mm_wq.
*/
+struct cpuset_migrate_mm_work {
+ struct work_struct work;
+ struct mm_struct *mm;
+ nodemask_t from;
+ nodemask_t to;
+};
+
+static void cpuset_migrate_mm_workfn(struct work_struct *work)
+{
+ struct cpuset_migrate_mm_work *mwork =
+ container_of(work, struct cpuset_migrate_mm_work, work);
+
+ /* on a wq worker, no need to worry about %current's mems_allowed */
+ do_migrate_pages(mwork->mm, &mwork->from, &mwork->to, MPOL_MF_MOVE_ALL);
+ mmput(mwork->mm);
+ kfree(mwork);
+}
+
static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
const nodemask_t *to)
{
- struct task_struct *tsk = current;
-
- tsk->mems_allowed = *to;
+ struct cpuset_migrate_mm_work *mwork;
- do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);
+ mwork = kzalloc(sizeof(*mwork), GFP_KERNEL);
+ if (mwork) {
+ mwork->mm = mm;
+ mwork->from = *from;
+ mwork->to = *to;
+ INIT_WORK(&mwork->work, cpuset_migrate_mm_workfn);
+ queue_work(cpuset_migrate_mm_wq, &mwork->work);
+ } else {
+ mmput(mm);
+ }
+}
- rcu_read_lock();
- guarantee_online_mems(task_cs(tsk), &tsk->mems_allowed);
- rcu_read_unlock();
+void cpuset_post_attach_flush(void)
+{
+ flush_workqueue(cpuset_migrate_mm_wq);
}
/*
@@ -1097,7 +1119,8 @@ static void update_tasks_nodemask(struct cpuset *cs)
mpol_rebind_mm(mm, &cs->mems_allowed);
if (migrate)
cpuset_migrate_mm(mm, &cs->old_mems_allowed, &newmems);
- mmput(mm);
+ else
+ mmput(mm);
}
css_task_iter_end(&it);
@@ -1545,11 +1568,11 @@ static void cpuset_attach(struct cgroup_taskset *tset)
* @old_mems_allowed is the right nodesets that we
* migrate mm from.
*/
- if (is_memory_migrate(cs)) {
+ if (is_memory_migrate(cs))
cpuset_migrate_mm(mm, &oldcs->old_mems_allowed,
&cpuset_attach_nodemask_to);
- }
- mmput(mm);
+ else
+ mmput(mm);
}
}
@@ -1714,6 +1737,7 @@ out_unlock:
mutex_unlock(&cpuset_mutex);
kernfs_unbreak_active_protection(of->kn);
css_put(&cs->css);
+ flush_workqueue(cpuset_migrate_mm_wq);
return retval ?: nbytes;
}
@@ -2359,6 +2383,9 @@ void __init cpuset_init_smp(void)
top_cpuset.effective_mems = node_states[N_MEMORY];
register_hotmemory_notifier(&cpuset_track_online_nodes_nb);
+
+ cpuset_migrate_mm_wq = alloc_ordered_workqueue("cpuset_migrate_mm", 0);
+ BUG_ON(!cpuset_migrate_mm_wq);
}
/**
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index e1dbf4a2c69e..90ff129c88a2 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -153,13 +153,11 @@ static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
} else {
kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
__func__, bp->bp_addr);
-#ifdef CONFIG_DEBUG_RODATA
if (!bp->bp_type) {
kdb_printf("Software breakpoints are unavailable.\n"
- " Change the kernel CONFIG_DEBUG_RODATA=n\n"
+ " Boot the kernel with rodata=off\n"
" OR use hw breaks: help bph\n");
}
-#endif
return 1;
}
return 0;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5946460b2425..712570dddacd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -64,8 +64,17 @@ static void remote_function(void *data)
struct task_struct *p = tfc->p;
if (p) {
- tfc->ret = -EAGAIN;
- if (task_cpu(p) != smp_processor_id() || !task_curr(p))
+ /* -EAGAIN */
+ if (task_cpu(p) != smp_processor_id())
+ return;
+
+ /*
+ * Now that we're on right CPU with IRQs disabled, we can test
+ * if we hit the right task without races.
+ */
+
+ tfc->ret = -ESRCH; /* No such (running) process */
+ if (p != current)
return;
}
@@ -92,13 +101,17 @@ task_function_call(struct task_struct *p, remote_function_f func, void *info)
.p = p,
.func = func,
.info = info,
- .ret = -ESRCH, /* No such (running) process */
+ .ret = -EAGAIN,
};
+ int ret;
- if (task_curr(p))
- smp_call_function_single(task_cpu(p), remote_function, &data, 1);
+ do {
+ ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1);
+ if (!ret)
+ ret = data.ret;
+ } while (ret == -EAGAIN);
- return data.ret;
+ return ret;
}
/**
@@ -169,19 +182,6 @@ static bool is_kernel_event(struct perf_event *event)
* rely on ctx->is_active and therefore cannot use event_function_call().
* See perf_install_in_context().
*
- * This is because we need a ctx->lock serialized variable (ctx->is_active)
- * to reliably determine if a particular task/context is scheduled in. The
- * task_curr() use in task_function_call() is racy in that a remote context
- * switch is not a single atomic operation.
- *
- * As is, the situation is 'safe' because we set rq->curr before we do the
- * actual context switch. This means that task_curr() will fail early, but
- * we'll continue spinning on ctx->is_active until we've passed
- * perf_event_task_sched_out().
- *
- * Without this ctx->lock serialized variable we could have race where we find
- * the task (and hence the context) would not be active while in fact they are.
- *
* If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
*/
@@ -212,7 +212,7 @@ static int event_function(void *info)
*/
if (ctx->task) {
if (ctx->task != current) {
- ret = -EAGAIN;
+ ret = -ESRCH;
goto unlock;
}
@@ -276,10 +276,10 @@ static void event_function_call(struct perf_event *event, event_f func, void *da
return;
}
-again:
if (task == TASK_TOMBSTONE)
return;
+again:
if (!task_function_call(task, event_function, &efs))
return;
@@ -289,13 +289,15 @@ again:
* a concurrent perf_event_context_sched_out().
*/
task = ctx->task;
- if (task != TASK_TOMBSTONE) {
- if (ctx->is_active) {
- raw_spin_unlock_irq(&ctx->lock);
- goto again;
- }
- func(event, NULL, ctx, data);
+ if (task == TASK_TOMBSTONE) {
+ raw_spin_unlock_irq(&ctx->lock);
+ return;
}
+ if (ctx->is_active) {
+ raw_spin_unlock_irq(&ctx->lock);
+ goto again;
+ }
+ func(event, NULL, ctx, data);
raw_spin_unlock_irq(&ctx->lock);
}
@@ -314,6 +316,7 @@ again:
enum event_type_t {
EVENT_FLEXIBLE = 0x1,
EVENT_PINNED = 0x2,
+ EVENT_TIME = 0x4,
EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
};
@@ -321,7 +324,13 @@ enum event_type_t {
* perf_sched_events : >0 events exist
* perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
*/
-struct static_key_deferred perf_sched_events __read_mostly;
+
+static void perf_sched_delayed(struct work_struct *work);
+DEFINE_STATIC_KEY_FALSE(perf_sched_events);
+static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
+static DEFINE_MUTEX(perf_sched_mutex);
+static atomic_t perf_sched_count;
+
static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
static DEFINE_PER_CPU(int, perf_sched_cb_usages);
@@ -1288,16 +1297,18 @@ static u64 perf_event_time(struct perf_event *event)
/*
* Update the total_time_enabled and total_time_running fields for a event.
- * The caller of this function needs to hold the ctx->lock.
*/
static void update_event_times(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
u64 run_end;
+ lockdep_assert_held(&ctx->lock);
+
if (event->state < PERF_EVENT_STATE_INACTIVE ||
event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
return;
+
/*
* in cgroup mode, time_enabled represents
* the time the event was enabled AND active
@@ -1645,7 +1656,7 @@ out:
static bool is_orphaned_event(struct perf_event *event)
{
- return event->state == PERF_EVENT_STATE_EXIT;
+ return event->state == PERF_EVENT_STATE_DEAD;
}
static inline int pmu_filter_match(struct perf_event *event)
@@ -1690,14 +1701,14 @@ event_sched_out(struct perf_event *event,
perf_pmu_disable(event->pmu);
+ event->tstamp_stopped = tstamp;
+ event->pmu->del(event, 0);
+ event->oncpu = -1;
event->state = PERF_EVENT_STATE_INACTIVE;
if (event->pending_disable) {
event->pending_disable = 0;
event->state = PERF_EVENT_STATE_OFF;
}
- event->tstamp_stopped = tstamp;
- event->pmu->del(event, 0);
- event->oncpu = -1;
if (!is_software_event(event))
cpuctx->active_oncpu--;
@@ -1732,7 +1743,6 @@ group_sched_out(struct perf_event *group_event,
}
#define DETACH_GROUP 0x01UL
-#define DETACH_STATE 0x02UL
/*
* Cross CPU call to remove a performance event
@@ -1752,8 +1762,6 @@ __perf_remove_from_context(struct perf_event *event,
if (flags & DETACH_GROUP)
perf_group_detach(event);
list_del_event(event, ctx);
- if (flags & DETACH_STATE)
- event->state = PERF_EVENT_STATE_EXIT;
if (!ctx->nr_events && ctx->is_active) {
ctx->is_active = 0;
@@ -2063,14 +2071,27 @@ static void add_event_to_ctx(struct perf_event *event,
event->tstamp_stopped = tstamp;
}
-static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx);
+static void ctx_sched_out(struct perf_event_context *ctx,
+ struct perf_cpu_context *cpuctx,
+ enum event_type_t event_type);
static void
ctx_sched_in(struct perf_event_context *ctx,
struct perf_cpu_context *cpuctx,
enum event_type_t event_type,
struct task_struct *task);
+static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
+ struct perf_event_context *ctx)
+{
+ if (!cpuctx->task_ctx)
+ return;
+
+ if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
+ return;
+
+ ctx_sched_out(ctx, cpuctx, EVENT_ALL);
+}
+
static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx,
struct task_struct *task)
@@ -2097,49 +2118,68 @@ static void ctx_resched(struct perf_cpu_context *cpuctx,
/*
* Cross CPU call to install and enable a performance event
*
- * Must be called with ctx->mutex held
+ * Very similar to remote_function() + event_function() but cannot assume that
+ * things like ctx->is_active and cpuctx->task_ctx are set.
*/
static int __perf_install_in_context(void *info)
{
- struct perf_event_context *ctx = info;
+ struct perf_event *event = info;
+ struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
struct perf_event_context *task_ctx = cpuctx->task_ctx;
+ bool activate = true;
+ int ret = 0;
raw_spin_lock(&cpuctx->ctx.lock);
if (ctx->task) {
raw_spin_lock(&ctx->lock);
- /*
- * If we hit the 'wrong' task, we've since scheduled and
- * everything should be sorted, nothing to do!
- */
task_ctx = ctx;
- if (ctx->task != current)
+
+ /* If we're on the wrong CPU, try again */
+ if (task_cpu(ctx->task) != smp_processor_id()) {
+ ret = -ESRCH;
goto unlock;
+ }
/*
- * If task_ctx is set, it had better be to us.
+ * If we're on the right CPU, see if the task we target is
+ * current, if not we don't have to activate the ctx, a future
+ * context switch will do that for us.
*/
- WARN_ON_ONCE(cpuctx->task_ctx != ctx && cpuctx->task_ctx);
+ if (ctx->task != current)
+ activate = false;
+ else
+ WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx);
+
} else if (task_ctx) {
raw_spin_lock(&task_ctx->lock);
}
- ctx_resched(cpuctx, task_ctx);
+ if (activate) {
+ ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+ add_event_to_ctx(event, ctx);
+ ctx_resched(cpuctx, task_ctx);
+ } else {
+ add_event_to_ctx(event, ctx);
+ }
+
unlock:
perf_ctx_unlock(cpuctx, task_ctx);
- return 0;
+ return ret;
}
/*
- * Attach a performance event to a context
+ * Attach a performance event to a context.
+ *
+ * Very similar to event_function_call, see comment there.
*/
static void
perf_install_in_context(struct perf_event_context *ctx,
struct perf_event *event,
int cpu)
{
- struct task_struct *task = NULL;
+ struct task_struct *task = READ_ONCE(ctx->task);
lockdep_assert_held(&ctx->mutex);
@@ -2147,40 +2187,46 @@ perf_install_in_context(struct perf_event_context *ctx,
if (event->cpu != -1)
event->cpu = cpu;
+ if (!task) {
+ cpu_function_call(cpu, __perf_install_in_context, event);
+ return;
+ }
+
+ /*
+ * Should not happen, we validate the ctx is still alive before calling.
+ */
+ if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
+ return;
+
/*
* Installing events is tricky because we cannot rely on ctx->is_active
* to be set in case this is the nr_events 0 -> 1 transition.
- *
- * So what we do is we add the event to the list here, which will allow
- * a future context switch to DTRT and then send a racy IPI. If the IPI
- * fails to hit the right task, this means a context switch must have
- * happened and that will have taken care of business.
*/
- raw_spin_lock_irq(&ctx->lock);
- task = ctx->task;
+again:
/*
- * Worse, we cannot even rely on the ctx actually existing anymore. If
- * between find_get_context() and perf_install_in_context() the task
- * went through perf_event_exit_task() its dead and we should not be
- * adding new events.
+ * Cannot use task_function_call() because we need to run on the task's
+ * CPU regardless of whether its current or not.
*/
- if (task == TASK_TOMBSTONE) {
+ if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event))
+ return;
+
+ raw_spin_lock_irq(&ctx->lock);
+ task = ctx->task;
+ if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
+ /*
+ * Cannot happen because we already checked above (which also
+ * cannot happen), and we hold ctx->mutex, which serializes us
+ * against perf_event_exit_task_context().
+ */
raw_spin_unlock_irq(&ctx->lock);
return;
}
- update_context_time(ctx);
+ raw_spin_unlock_irq(&ctx->lock);
/*
- * Update cgrp time only if current cgrp matches event->cgrp.
- * Must be done before calling add_event_to_ctx().
+ * Since !ctx->is_active doesn't mean anything, we must IPI
+ * unconditionally.
*/
- update_cgrp_time_from_event(event);
- add_event_to_ctx(event, ctx);
- raw_spin_unlock_irq(&ctx->lock);
-
- if (task)
- task_function_call(task, __perf_install_in_context, ctx);
- else
- cpu_function_call(cpu, __perf_install_in_context, ctx);
+ goto again;
}
/*
@@ -2219,17 +2265,18 @@ static void __perf_event_enable(struct perf_event *event,
event->state <= PERF_EVENT_STATE_ERROR)
return;
- update_context_time(ctx);
+ if (ctx->is_active)
+ ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+
__perf_event_mark_enabled(event);
if (!ctx->is_active)
return;
if (!event_filter_match(event)) {
- if (is_cgroup_event(event)) {
- perf_cgroup_set_timestamp(current, ctx); // XXX ?
+ if (is_cgroup_event(event))
perf_cgroup_defer_enabled(event);
- }
+ ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
return;
}
@@ -2237,8 +2284,10 @@ static void __perf_event_enable(struct perf_event *event,
* If the event is in a group and isn't the group leader,
* then don't put it on unless the group is on.
*/
- if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
+ if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
+ ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
return;
+ }
task_ctx = cpuctx->task_ctx;
if (ctx->task)
@@ -2344,24 +2393,33 @@ static void ctx_sched_out(struct perf_event_context *ctx,
}
ctx->is_active &= ~event_type;
+ if (!(ctx->is_active & EVENT_ALL))
+ ctx->is_active = 0;
+
if (ctx->task) {
WARN_ON_ONCE(cpuctx->task_ctx != ctx);
if (!ctx->is_active)
cpuctx->task_ctx = NULL;
}
- update_context_time(ctx);
- update_cgrp_time_from_cpuctx(cpuctx);
- if (!ctx->nr_active)
+ is_active ^= ctx->is_active; /* changed bits */
+
+ if (is_active & EVENT_TIME) {
+ /* update (and stop) ctx time */
+ update_context_time(ctx);
+ update_cgrp_time_from_cpuctx(cpuctx);
+ }
+
+ if (!ctx->nr_active || !(is_active & EVENT_ALL))
return;
perf_pmu_disable(ctx->pmu);
- if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) {
+ if (is_active & EVENT_PINNED) {
list_for_each_entry(event, &ctx->pinned_groups, group_entry)
group_sched_out(event, cpuctx, ctx);
}
- if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) {
+ if (is_active & EVENT_FLEXIBLE) {
list_for_each_entry(event, &ctx->flexible_groups, group_entry)
group_sched_out(event, cpuctx, ctx);
}
@@ -2641,18 +2699,6 @@ void __perf_event_task_sched_out(struct task_struct *task,
perf_cgroup_sched_out(task, next);
}
-static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
-{
- if (!cpuctx->task_ctx)
- return;
-
- if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
- return;
-
- ctx_sched_out(ctx, cpuctx, EVENT_ALL);
-}
-
/*
* Called with IRQs disabled
*/
@@ -2735,7 +2781,7 @@ ctx_sched_in(struct perf_event_context *ctx,
if (likely(!ctx->nr_events))
return;
- ctx->is_active |= event_type;
+ ctx->is_active |= (event_type | EVENT_TIME);
if (ctx->task) {
if (!is_active)
cpuctx->task_ctx = ctx;
@@ -2743,18 +2789,24 @@ ctx_sched_in(struct perf_event_context *ctx,
WARN_ON_ONCE(cpuctx->task_ctx != ctx);
}
- now = perf_clock();
- ctx->timestamp = now;
- perf_cgroup_set_timestamp(task, ctx);
+ is_active ^= ctx->is_active; /* changed bits */
+
+ if (is_active & EVENT_TIME) {
+ /* start ctx time */
+ now = perf_clock();
+ ctx->timestamp = now;
+ perf_cgroup_set_timestamp(task, ctx);
+ }
+
/*
* First go through the list and put on any pinned groups
* in order to give them the best chance of going on.
*/
- if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED))
+ if (is_active & EVENT_PINNED)
ctx_pinned_sched_in(ctx, cpuctx);
/* Then walk through the lower prio flexible groups */
- if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE))
+ if (is_active & EVENT_FLEXIBLE)
ctx_flexible_sched_in(ctx, cpuctx);
}
@@ -3060,17 +3112,6 @@ done:
return rotate;
}
-#ifdef CONFIG_NO_HZ_FULL
-bool perf_event_can_stop_tick(void)
-{
- if (atomic_read(&nr_freq_events) ||
- __this_cpu_read(perf_throttled_count))
- return false;
- else
- return true;
-}
-#endif
-
void perf_event_task_tick(void)
{
struct list_head *head = this_cpu_ptr(&active_ctx_list);
@@ -3081,6 +3122,7 @@ void perf_event_task_tick(void)
__this_cpu_inc(perf_throttled_seq);
throttled = __this_cpu_xchg(perf_throttled_count, 0);
+ tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
perf_adjust_freq_unthr_context(ctx, throttled);
@@ -3120,6 +3162,7 @@ static void perf_event_enable_on_exec(int ctxn)
cpuctx = __get_cpu_context(ctx);
perf_ctx_lock(cpuctx, ctx);
+ ctx_sched_out(ctx, cpuctx, EVENT_TIME);
list_for_each_entry(event, &ctx->event_list, event_entry)
enabled |= event_enable_on_exec(event, ctx);
@@ -3511,6 +3554,28 @@ static void unaccount_event_cpu(struct perf_event *event, int cpu)
atomic_dec(&per_cpu(perf_cgroup_events, cpu));
}
+#ifdef CONFIG_NO_HZ_FULL
+static DEFINE_SPINLOCK(nr_freq_lock);
+#endif
+
+static void unaccount_freq_event_nohz(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ spin_lock(&nr_freq_lock);
+ if (atomic_dec_and_test(&nr_freq_events))
+ tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
+ spin_unlock(&nr_freq_lock);
+#endif
+}
+
+static void unaccount_freq_event(void)
+{
+ if (tick_nohz_full_enabled())
+ unaccount_freq_event_nohz();
+ else
+ atomic_dec(&nr_freq_events);
+}
+
static void unaccount_event(struct perf_event *event)
{
bool dec = false;
@@ -3527,7 +3592,7 @@ static void unaccount_event(struct perf_event *event)
if (event->attr.task)
atomic_dec(&nr_task_events);
if (event->attr.freq)
- atomic_dec(&nr_freq_events);
+ unaccount_freq_event();
if (event->attr.context_switch) {
dec = true;
atomic_dec(&nr_switch_events);
@@ -3537,12 +3602,22 @@ static void unaccount_event(struct perf_event *event)
if (has_branch_stack(event))
dec = true;
- if (dec)
- static_key_slow_dec_deferred(&perf_sched_events);
+ if (dec) {
+ if (!atomic_add_unless(&perf_sched_count, -1, 1))
+ schedule_delayed_work(&perf_sched_work, HZ);
+ }
unaccount_event_cpu(event, event->cpu);
}
+static void perf_sched_delayed(struct work_struct *work)
+{
+ mutex_lock(&perf_sched_mutex);
+ if (atomic_dec_and_test(&perf_sched_count))
+ static_branch_disable(&perf_sched_events);
+ mutex_unlock(&perf_sched_mutex);
+}
+
/*
* The following implement mutual exclusion of events on "exclusive" pmus
* (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
@@ -3752,30 +3827,42 @@ static void put_event(struct perf_event *event)
*/
int perf_event_release_kernel(struct perf_event *event)
{
- struct perf_event_context *ctx;
+ struct perf_event_context *ctx = event->ctx;
struct perf_event *child, *tmp;
+ /*
+ * If we got here through err_file: fput(event_file); we will not have
+ * attached to a context yet.
+ */
+ if (!ctx) {
+ WARN_ON_ONCE(event->attach_state &
+ (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
+ goto no_ctx;
+ }
+
if (!is_kernel_event(event))
perf_remove_from_owner(event);
ctx = perf_event_ctx_lock(event);
WARN_ON_ONCE(ctx->parent_ctx);
- perf_remove_from_context(event, DETACH_GROUP | DETACH_STATE);
- perf_event_ctx_unlock(event, ctx);
+ perf_remove_from_context(event, DETACH_GROUP);
+ raw_spin_lock_irq(&ctx->lock);
/*
- * At this point we must have event->state == PERF_EVENT_STATE_EXIT,
- * either from the above perf_remove_from_context() or through
- * perf_event_exit_event().
+ * Mark this even as STATE_DEAD, there is no external reference to it
+ * anymore.
*
- * Therefore, anybody acquiring event->child_mutex after the below
- * loop _must_ also see this, most importantly inherit_event() which
- * will avoid placing more children on the list.
+ * Anybody acquiring event->child_mutex after the below loop _must_
+ * also see this, most importantly inherit_event() which will avoid
+ * placing more children on the list.
*
* Thus this guarantees that we will in fact observe and kill _ALL_
* child events.
*/
- WARN_ON_ONCE(event->state != PERF_EVENT_STATE_EXIT);
+ event->state = PERF_EVENT_STATE_DEAD;
+ raw_spin_unlock_irq(&ctx->lock);
+
+ perf_event_ctx_unlock(event, ctx);
again:
mutex_lock(&event->child_mutex);
@@ -3830,8 +3917,8 @@ again:
}
mutex_unlock(&event->child_mutex);
- /* Must be the last reference */
- put_event(event);
+no_ctx:
+ put_event(event); /* Must be the 'last' reference */
return 0;
}
EXPORT_SYMBOL_GPL(perf_event_release_kernel);
@@ -3988,7 +4075,7 @@ static bool is_event_hup(struct perf_event *event)
{
bool no_children;
- if (event->state != PERF_EVENT_STATE_EXIT)
+ if (event->state > PERF_EVENT_STATE_EXIT)
return false;
mutex_lock(&event->child_mutex);
@@ -6349,9 +6436,9 @@ static int __perf_event_overflow(struct perf_event *event,
if (unlikely(throttle
&& hwc->interrupts >= max_samples_per_tick)) {
__this_cpu_inc(perf_throttled_count);
+ tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
hwc->interrupts = MAX_INTERRUPTS;
perf_log_throttle(event, 0);
- tick_nohz_full_kick();
ret = 1;
}
}
@@ -6710,7 +6797,7 @@ static void swevent_hlist_release(struct swevent_htable *swhash)
kfree_rcu(hlist, rcu_head);
}
-static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
+static void swevent_hlist_put_cpu(int cpu)
{
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
@@ -6722,15 +6809,15 @@ static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
mutex_unlock(&swhash->hlist_mutex);
}
-static void swevent_hlist_put(struct perf_event *event)
+static void swevent_hlist_put(void)
{
int cpu;
for_each_possible_cpu(cpu)
- swevent_hlist_put_cpu(event, cpu);
+ swevent_hlist_put_cpu(cpu);
}
-static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
+static int swevent_hlist_get_cpu(int cpu)
{
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
int err = 0;
@@ -6753,14 +6840,13 @@ exit:
return err;
}
-static int swevent_hlist_get(struct perf_event *event)
+static int swevent_hlist_get(void)
{
- int err;
- int cpu, failed_cpu;
+ int err, cpu, failed_cpu;
get_online_cpus();
for_each_possible_cpu(cpu) {
- err = swevent_hlist_get_cpu(event, cpu);
+ err = swevent_hlist_get_cpu(cpu);
if (err) {
failed_cpu = cpu;
goto fail;
@@ -6773,7 +6859,7 @@ fail:
for_each_possible_cpu(cpu) {
if (cpu == failed_cpu)
break;
- swevent_hlist_put_cpu(event, cpu);
+ swevent_hlist_put_cpu(cpu);
}
put_online_cpus();
@@ -6789,7 +6875,7 @@ static void sw_perf_event_destroy(struct perf_event *event)
WARN_ON(event->parent);
static_key_slow_dec(&perf_swevent_enabled[event_id]);
- swevent_hlist_put(event);
+ swevent_hlist_put();
}
static int perf_swevent_init(struct perf_event *event)
@@ -6820,7 +6906,7 @@ static int perf_swevent_init(struct perf_event *event)
if (!event->parent) {
int err;
- err = swevent_hlist_get(event);
+ err = swevent_hlist_get();
if (err)
return err;
@@ -7741,6 +7827,27 @@ static void account_event_cpu(struct perf_event *event, int cpu)
atomic_inc(&per_cpu(perf_cgroup_events, cpu));
}
+/* Freq events need the tick to stay alive (see perf_event_task_tick). */
+static void account_freq_event_nohz(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ /* Lock so we don't race with concurrent unaccount */
+ spin_lock(&nr_freq_lock);
+ if (atomic_inc_return(&nr_freq_events) == 1)
+ tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
+ spin_unlock(&nr_freq_lock);
+#endif
+}
+
+static void account_freq_event(void)
+{
+ if (tick_nohz_full_enabled())
+ account_freq_event_nohz();
+ else
+ atomic_inc(&nr_freq_events);
+}
+
+
static void account_event(struct perf_event *event)
{
bool inc = false;
@@ -7756,10 +7863,8 @@ static void account_event(struct perf_event *event)
atomic_inc(&nr_comm_events);
if (event->attr.task)
atomic_inc(&nr_task_events);
- if (event->attr.freq) {
- if (atomic_inc_return(&nr_freq_events) == 1)
- tick_nohz_full_kick_all();
- }
+ if (event->attr.freq)
+ account_freq_event();
if (event->attr.context_switch) {
atomic_inc(&nr_switch_events);
inc = true;
@@ -7769,8 +7874,28 @@ static void account_event(struct perf_event *event)
if (is_cgroup_event(event))
inc = true;
- if (inc)
- static_key_slow_inc(&perf_sched_events.key);
+ if (inc) {
+ if (atomic_inc_not_zero(&perf_sched_count))
+ goto enabled;
+
+ mutex_lock(&perf_sched_mutex);
+ if (!atomic_read(&perf_sched_count)) {
+ static_branch_enable(&perf_sched_events);
+ /*
+ * Guarantee that all CPUs observe they key change and
+ * call the perf scheduling hooks before proceeding to
+ * install events that need them.
+ */
+ synchronize_sched();
+ }
+ /*
+ * Now that we have waited for the sync_sched(), allow further
+ * increments to by-pass the mutex.
+ */
+ atomic_inc(&perf_sched_count);
+ mutex_unlock(&perf_sched_mutex);
+ }
+enabled:
account_event_cpu(event, event->cpu);
}
@@ -7906,6 +8031,9 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
}
}
+ /* symmetric to unaccount_event() in _free_event() */
+ account_event(event);
+
return event;
err_per_task:
@@ -8269,8 +8397,6 @@ SYSCALL_DEFINE5(perf_event_open,
}
}
- account_event(event);
-
/*
* Special case software events and allow them to be part of
* any hardware group.
@@ -8389,10 +8515,19 @@ SYSCALL_DEFINE5(perf_event_open,
if (move_group) {
gctx = group_leader->ctx;
mutex_lock_double(&gctx->mutex, &ctx->mutex);
+ if (gctx->task == TASK_TOMBSTONE) {
+ err = -ESRCH;
+ goto err_locked;
+ }
} else {
mutex_lock(&ctx->mutex);
}
+ if (ctx->task == TASK_TOMBSTONE) {
+ err = -ESRCH;
+ goto err_locked;
+ }
+
if (!perf_event_validate_size(event)) {
err = -E2BIG;
goto err_locked;
@@ -8509,7 +8644,12 @@ err_context:
perf_unpin_context(ctx);
put_ctx(ctx);
err_alloc:
- free_event(event);
+ /*
+ * If event_file is set, the fput() above will have called ->release()
+ * and that will take care of freeing the event.
+ */
+ if (!event_file)
+ free_event(event);
err_cpus:
put_online_cpus();
err_task:
@@ -8553,8 +8693,6 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
/* Mark owner so we could distinguish it from user events. */
event->owner = TASK_TOMBSTONE;
- account_event(event);
-
ctx = find_get_context(event->pmu, task, event);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
@@ -8563,12 +8701,14 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
+ if (ctx->task == TASK_TOMBSTONE) {
+ err = -ESRCH;
+ goto err_unlock;
+ }
+
if (!exclusive_event_installable(event, ctx)) {
- mutex_unlock(&ctx->mutex);
- perf_unpin_context(ctx);
- put_ctx(ctx);
err = -EBUSY;
- goto err_free;
+ goto err_unlock;
}
perf_install_in_context(ctx, event, cpu);
@@ -8577,6 +8717,10 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
return event;
+err_unlock:
+ mutex_unlock(&ctx->mutex);
+ perf_unpin_context(ctx);
+ put_ctx(ctx);
err_free:
free_event(event);
err:
@@ -8695,7 +8839,7 @@ perf_event_exit_event(struct perf_event *child_event,
if (parent_event)
perf_group_detach(child_event);
list_del_event(child_event, child_ctx);
- child_event->state = PERF_EVENT_STATE_EXIT; /* see perf_event_release_kernel() */
+ child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
raw_spin_unlock_irq(&child_ctx->lock);
/*
@@ -9206,7 +9350,7 @@ static void perf_event_init_cpu(int cpu)
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
- if (swhash->hlist_refcount > 0) {
+ if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
struct swevent_hlist *hlist;
hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
@@ -9282,11 +9426,9 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
- case CPU_DOWN_FAILED:
perf_event_init_cpu(cpu);
break;
- case CPU_UP_CANCELED:
case CPU_DOWN_PREPARE:
perf_event_exit_cpu(cpu);
break;
@@ -9315,9 +9457,6 @@ void __init perf_event_init(void)
ret = init_hw_breakpoint();
WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
- /* do not patch jump label more than once per second */
- jump_label_rate_limit(&perf_sched_events, HZ);
-
/*
* Build time assertion that we keep the data_head at the intended
* location. IOW, validation we got the __reserved[] size right.
@@ -9337,6 +9476,7 @@ ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
return 0;
}
+EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
static int __init perf_event_sysfs_init(void)
{
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 0167679182c0..5f6ce931f1ea 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1178,6 +1178,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
goto free_area;
area->xol_mapping.name = "[uprobes]";
+ area->xol_mapping.fault = NULL;
area->xol_mapping.pages = area->pages;
area->pages[0] = alloc_page(GFP_HIGHUSER);
if (!area->pages[0])
diff --git a/kernel/futex.c b/kernel/futex.c
index 5d6ce6413ef1..a5d2e74c89e0 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -124,16 +124,16 @@
* futex_wait(futex, val);
*
* waiters++; (a)
- * mb(); (A) <-- paired with -.
- * |
- * lock(hash_bucket(futex)); |
- * |
- * uval = *futex; |
- * | *futex = newval;
- * | sys_futex(WAKE, futex);
- * | futex_wake(futex);
- * |
- * `-------> mb(); (B)
+ * smp_mb(); (A) <-- paired with -.
+ * |
+ * lock(hash_bucket(futex)); |
+ * |
+ * uval = *futex; |
+ * | *futex = newval;
+ * | sys_futex(WAKE, futex);
+ * | futex_wake(futex);
+ * |
+ * `--------> smp_mb(); (B)
* if (uval == val)
* queue();
* unlock(hash_bucket(futex));
@@ -334,7 +334,7 @@ static inline void futex_get_mm(union futex_key *key)
/*
* Ensure futex_get_mm() implies a full barrier such that
* get_futex_key() implies a full barrier. This is relied upon
- * as full barrier (B), see the ordering comment above.
+ * as smp_mb(); (B), see the ordering comment above.
*/
smp_mb__after_atomic();
}
@@ -407,10 +407,10 @@ static void get_futex_key_refs(union futex_key *key)
switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
case FUT_OFF_INODE:
- ihold(key->shared.inode); /* implies MB (B) */
+ ihold(key->shared.inode); /* implies smp_mb(); (B) */
break;
case FUT_OFF_MMSHARED:
- futex_get_mm(key); /* implies MB (B) */
+ futex_get_mm(key); /* implies smp_mb(); (B) */
break;
default:
/*
@@ -418,7 +418,7 @@ static void get_futex_key_refs(union futex_key *key)
* mm, therefore the only purpose of calling get_futex_key_refs
* is because we need the barrier for the lockless waiter check.
*/
- smp_mb(); /* explicit MB (B) */
+ smp_mb(); /* explicit smp_mb(); (B) */
}
}
@@ -497,7 +497,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
if (!fshared) {
key->private.mm = mm;
key->private.address = address;
- get_futex_key_refs(key); /* implies MB (B) */
+ get_futex_key_refs(key); /* implies smp_mb(); (B) */
return 0;
}
@@ -520,7 +520,20 @@ again:
else
err = 0;
- lock_page(page);
+ /*
+ * The treatment of mapping from this point on is critical. The page
+ * lock protects many things but in this context the page lock
+ * stabilizes mapping, prevents inode freeing in the shared
+ * file-backed region case and guards against movement to swap cache.
+ *
+ * Strictly speaking the page lock is not needed in all cases being
+ * considered here and page lock forces unnecessarily serialization
+ * From this point on, mapping will be re-verified if necessary and
+ * page lock will be acquired only if it is unavoidable
+ */
+ page = compound_head(page);
+ mapping = READ_ONCE(page->mapping);
+
/*
* If page->mapping is NULL, then it cannot be a PageAnon
* page; but it might be the ZERO_PAGE or in the gate area or
@@ -536,19 +549,31 @@ again:
* shmem_writepage move it from filecache to swapcache beneath us:
* an unlikely race, but we do need to retry for page->mapping.
*/
- mapping = compound_head(page)->mapping;
- if (!mapping) {
- int shmem_swizzled = PageSwapCache(page);
+ if (unlikely(!mapping)) {
+ int shmem_swizzled;
+
+ /*
+ * Page lock is required to identify which special case above
+ * applies. If this is really a shmem page then the page lock
+ * will prevent unexpected transitions.
+ */
+ lock_page(page);
+ shmem_swizzled = PageSwapCache(page) || page->mapping;
unlock_page(page);
put_page(page);
+
if (shmem_swizzled)
goto again;
+
return -EFAULT;
}
/*
* Private mappings are handled in a simple way.
*
+ * If the futex key is stored on an anonymous page, then the associated
+ * object is the mm which is implicitly pinned by the calling process.
+ *
* NOTE: When userspace waits on a MAP_SHARED mapping, even if
* it's a read-only handle, it's expected that futexes attach to
* the object not the particular process.
@@ -566,16 +591,74 @@ again:
key->both.offset |= FUT_OFF_MMSHARED; /* ref taken on mm */
key->private.mm = mm;
key->private.address = address;
+
+ get_futex_key_refs(key); /* implies smp_mb(); (B) */
+
} else {
+ struct inode *inode;
+
+ /*
+ * The associated futex object in this case is the inode and
+ * the page->mapping must be traversed. Ordinarily this should
+ * be stabilised under page lock but it's not strictly
+ * necessary in this case as we just want to pin the inode, not
+ * update the radix tree or anything like that.
+ *
+ * The RCU read lock is taken as the inode is finally freed
+ * under RCU. If the mapping still matches expectations then the
+ * mapping->host can be safely accessed as being a valid inode.
+ */
+ rcu_read_lock();
+
+ if (READ_ONCE(page->mapping) != mapping) {
+ rcu_read_unlock();
+ put_page(page);
+
+ goto again;
+ }
+
+ inode = READ_ONCE(mapping->host);
+ if (!inode) {
+ rcu_read_unlock();
+ put_page(page);
+
+ goto again;
+ }
+
+ /*
+ * Take a reference unless it is about to be freed. Previously
+ * this reference was taken by ihold under the page lock
+ * pinning the inode in place so i_lock was unnecessary. The
+ * only way for this check to fail is if the inode was
+ * truncated in parallel so warn for now if this happens.
+ *
+ * We are not calling into get_futex_key_refs() in file-backed
+ * cases, therefore a successful atomic_inc return below will
+ * guarantee that get_futex_key() will still imply smp_mb(); (B).
+ */
+ if (WARN_ON_ONCE(!atomic_inc_not_zero(&inode->i_count))) {
+ rcu_read_unlock();
+ put_page(page);
+
+ goto again;
+ }
+
+ /* Should be impossible but lets be paranoid for now */
+ if (WARN_ON_ONCE(inode->i_mapping != mapping)) {
+ err = -EFAULT;
+ rcu_read_unlock();
+ iput(inode);
+
+ goto out;
+ }
+
key->both.offset |= FUT_OFF_INODE; /* inode-based key */
- key->shared.inode = mapping->host;
+ key->shared.inode = inode;
key->shared.pgoff = basepage_index(page);
+ rcu_read_unlock();
}
- get_futex_key_refs(key); /* implies MB (B) */
-
out:
- unlock_page(page);
put_page(page);
return err;
}
@@ -1864,7 +1947,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
q->lock_ptr = &hb->lock;
- spin_lock(&hb->lock); /* implies MB (A) */
+ spin_lock(&hb->lock); /* implies smp_mb(); (A) */
return hb;
}
@@ -1927,8 +2010,12 @@ static int unqueue_me(struct futex_q *q)
/* In the common case we don't take the spinlock, which is nice. */
retry:
- lock_ptr = q->lock_ptr;
- barrier();
+ /*
+ * q->lock_ptr can change between this read and the following spin_lock.
+ * Use READ_ONCE to forbid the compiler from reloading q->lock_ptr and
+ * optimizing lock_ptr out of the logic below.
+ */
+ lock_ptr = READ_ONCE(q->lock_ptr);
if (lock_ptr != NULL) {
spin_lock(lock_ptr);
/*
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 3b48dab80164..3bbfd6a9c475 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -64,6 +64,10 @@ config IRQ_DOMAIN_HIERARCHY
bool
select IRQ_DOMAIN
+# Generic IRQ IPI support
+config GENERIC_IRQ_IPI
+ bool
+
# Generic MSI interrupt support
config GENERIC_MSI_IRQ
bool
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 2fc9cbdf35b6..2ee42e95a3ce 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
obj-$(CONFIG_GENERIC_IRQ_MIGRATION) += cpuhotplug.o
obj-$(CONFIG_PM_SLEEP) += pm.o
obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o
+obj-$(CONFIG_GENERIC_IRQ_IPI) += ipi.o
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 5797909f4e5b..2f9f2b0e79f2 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -961,6 +961,7 @@ void irq_chip_mask_parent(struct irq_data *data)
data = data->parent_data;
data->chip->irq_mask(data);
}
+EXPORT_SYMBOL_GPL(irq_chip_mask_parent);
/**
* irq_chip_unmask_parent - Unmask the parent interrupt
@@ -971,6 +972,7 @@ void irq_chip_unmask_parent(struct irq_data *data)
data = data->parent_data;
data->chip->irq_unmask(data);
}
+EXPORT_SYMBOL_GPL(irq_chip_unmask_parent);
/**
* irq_chip_eoi_parent - Invoke EOI on the parent interrupt
@@ -981,6 +983,7 @@ void irq_chip_eoi_parent(struct irq_data *data)
data = data->parent_data;
data->chip->irq_eoi(data);
}
+EXPORT_SYMBOL_GPL(irq_chip_eoi_parent);
/**
* irq_chip_set_affinity_parent - Set affinity on the parent interrupt
@@ -1016,6 +1019,7 @@ int irq_chip_set_type_parent(struct irq_data *data, unsigned int type)
return -ENOSYS;
}
+EXPORT_SYMBOL_GPL(irq_chip_set_type_parent);
/**
* irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 57bff7857e87..a15b5485b446 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -136,10 +136,9 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
{
irqreturn_t retval = IRQ_NONE;
unsigned int flags = 0, irq = desc->irq_data.irq;
- struct irqaction *action = desc->action;
+ struct irqaction *action;
- /* action might have become NULL since we dropped the lock */
- while (action) {
+ for_each_action_of_desc(desc, action) {
irqreturn_t res;
trace_irq_handler_entry(irq, action);
@@ -173,7 +172,6 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
}
retval |= res;
- action = action->next;
}
add_interrupt_randomness(irq, flags);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index fcab63c66905..09be2c903c6d 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -131,6 +131,9 @@ static inline void chip_bus_sync_unlock(struct irq_desc *desc)
#define IRQ_GET_DESC_CHECK_GLOBAL (_IRQ_DESC_CHECK)
#define IRQ_GET_DESC_CHECK_PERCPU (_IRQ_DESC_CHECK | _IRQ_DESC_PERCPU)
+#define for_each_action_of_desc(desc, act) \
+ for (act = desc->act; act; act = act->next)
+
struct irq_desc *
__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
unsigned int check);
@@ -160,6 +163,8 @@ irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags)
__irq_put_desc_unlock(desc, flags, false);
}
+#define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
+
/*
* Manipulation functions for irq_data.state
*/
@@ -188,6 +193,8 @@ static inline bool irqd_has_set(struct irq_data *d, unsigned int mask)
return __irqd_to_state(d) & mask;
}
+#undef __irqd_to_state
+
static inline void kstat_incr_irqs_this_cpu(struct irq_desc *desc)
{
__this_cpu_inc(*desc->kstat_irqs);
diff --git a/kernel/irq/ipi.c b/kernel/irq/ipi.c
new file mode 100644
index 000000000000..c37f34b00a11
--- /dev/null
+++ b/kernel/irq/ipi.c
@@ -0,0 +1,326 @@
+/*
+ * linux/kernel/irq/ipi.c
+ *
+ * Copyright (C) 2015 Imagination Technologies Ltd
+ * Author: Qais Yousef <qais.yousef@imgtec.com>
+ *
+ * This file contains driver APIs to the IPI subsystem.
+ */
+
+#define pr_fmt(fmt) "genirq/ipi: " fmt
+
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+
+/**
+ * irq_reserve_ipi() - Setup an IPI to destination cpumask
+ * @domain: IPI domain
+ * @dest: cpumask of cpus which can receive the IPI
+ *
+ * Allocate a virq that can be used to send IPI to any CPU in dest mask.
+ *
+ * On success it'll return linux irq number and 0 on failure
+ */
+unsigned int irq_reserve_ipi(struct irq_domain *domain,
+ const struct cpumask *dest)
+{
+ unsigned int nr_irqs, offset;
+ struct irq_data *data;
+ int virq, i;
+
+ if (!domain ||!irq_domain_is_ipi(domain)) {
+ pr_warn("Reservation on a non IPI domain\n");
+ return 0;
+ }
+
+ if (!cpumask_subset(dest, cpu_possible_mask)) {
+ pr_warn("Reservation is not in possible_cpu_mask\n");
+ return 0;
+ }
+
+ nr_irqs = cpumask_weight(dest);
+ if (!nr_irqs) {
+ pr_warn("Reservation for empty destination mask\n");
+ return 0;
+ }
+
+ if (irq_domain_is_ipi_single(domain)) {
+ /*
+ * If the underlying implementation uses a single HW irq on
+ * all cpus then we only need a single Linux irq number for
+ * it. We have no restrictions vs. the destination mask. The
+ * underlying implementation can deal with holes nicely.
+ */
+ nr_irqs = 1;
+ offset = 0;
+ } else {
+ unsigned int next;
+
+ /*
+ * The IPI requires a seperate HW irq on each CPU. We require
+ * that the destination mask is consecutive. If an
+ * implementation needs to support holes, it can reserve
+ * several IPI ranges.
+ */
+ offset = cpumask_first(dest);
+ /*
+ * Find a hole and if found look for another set bit after the
+ * hole. For now we don't support this scenario.
+ */
+ next = cpumask_next_zero(offset, dest);
+ if (next < nr_cpu_ids)
+ next = cpumask_next(next, dest);
+ if (next < nr_cpu_ids) {
+ pr_warn("Destination mask has holes\n");
+ return 0;
+ }
+ }
+
+ virq = irq_domain_alloc_descs(-1, nr_irqs, 0, NUMA_NO_NODE);
+ if (virq <= 0) {
+ pr_warn("Can't reserve IPI, failed to alloc descs\n");
+ return 0;
+ }
+
+ virq = __irq_domain_alloc_irqs(domain, virq, nr_irqs, NUMA_NO_NODE,
+ (void *) dest, true);
+
+ if (virq <= 0) {
+ pr_warn("Can't reserve IPI, failed to alloc hw irqs\n");
+ goto free_descs;
+ }
+
+ for (i = 0; i < nr_irqs; i++) {
+ data = irq_get_irq_data(virq + i);
+ cpumask_copy(data->common->affinity, dest);
+ data->common->ipi_offset = offset;
+ }
+ return virq;
+
+free_descs:
+ irq_free_descs(virq, nr_irqs);
+ return 0;
+}
+
+/**
+ * irq_destroy_ipi() - unreserve an IPI that was previously allocated
+ * @irq: linux irq number to be destroyed
+ *
+ * Return the IPIs allocated with irq_reserve_ipi() to the system destroying
+ * all virqs associated with them.
+ */
+void irq_destroy_ipi(unsigned int irq)
+{
+ struct irq_data *data = irq_get_irq_data(irq);
+ struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+ struct irq_domain *domain;
+ unsigned int nr_irqs;
+
+ if (!irq || !data || !ipimask)
+ return;
+
+ domain = data->domain;
+ if (WARN_ON(domain == NULL))
+ return;
+
+ if (!irq_domain_is_ipi(domain)) {
+ pr_warn("Trying to destroy a non IPI domain!\n");
+ return;
+ }
+
+ if (irq_domain_is_ipi_per_cpu(domain))
+ nr_irqs = cpumask_weight(ipimask);
+ else
+ nr_irqs = 1;
+
+ irq_domain_free_irqs(irq, nr_irqs);
+}
+
+/**
+ * ipi_get_hwirq - Get the hwirq associated with an IPI to a cpu
+ * @irq: linux irq number
+ * @cpu: the target cpu
+ *
+ * When dealing with coprocessors IPI, we need to inform the coprocessor of
+ * the hwirq it needs to use to receive and send IPIs.
+ *
+ * Returns hwirq value on success and INVALID_HWIRQ on failure.
+ */
+irq_hw_number_t ipi_get_hwirq(unsigned int irq, unsigned int cpu)
+{
+ struct irq_data *data = irq_get_irq_data(irq);
+ struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+
+ if (!data || !ipimask || cpu > nr_cpu_ids)
+ return INVALID_HWIRQ;
+
+ if (!cpumask_test_cpu(cpu, ipimask))
+ return INVALID_HWIRQ;
+
+ /*
+ * Get the real hardware irq number if the underlying implementation
+ * uses a seperate irq per cpu. If the underlying implementation uses
+ * a single hardware irq for all cpus then the IPI send mechanism
+ * needs to take care of the cpu destinations.
+ */
+ if (irq_domain_is_ipi_per_cpu(data->domain))
+ data = irq_get_irq_data(irq + cpu - data->common->ipi_offset);
+
+ return data ? irqd_to_hwirq(data) : INVALID_HWIRQ;
+}
+EXPORT_SYMBOL_GPL(ipi_get_hwirq);
+
+static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data,
+ const struct cpumask *dest, unsigned int cpu)
+{
+ struct cpumask *ipimask = irq_data_get_affinity_mask(data);
+
+ if (!chip || !ipimask)
+ return -EINVAL;
+
+ if (!chip->ipi_send_single && !chip->ipi_send_mask)
+ return -EINVAL;
+
+ if (cpu > nr_cpu_ids)
+ return -EINVAL;
+
+ if (dest) {
+ if (!cpumask_subset(dest, ipimask))
+ return -EINVAL;
+ } else {
+ if (!cpumask_test_cpu(cpu, ipimask))
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/**
+ * __ipi_send_single - send an IPI to a target Linux SMP CPU
+ * @desc: pointer to irq_desc of the IRQ
+ * @cpu: destination CPU, must in the destination mask passed to
+ * irq_reserve_ipi()
+ *
+ * This function is for architecture or core code to speed up IPI sending. Not
+ * usable from driver code.
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int __ipi_send_single(struct irq_desc *desc, unsigned int cpu)
+{
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+
+#ifdef DEBUG
+ /*
+ * Minimise the overhead by omitting the checks for Linux SMP IPIs.
+ * Since the callers should be arch or core code which is generally
+ * trusted, only check for errors when debugging.
+ */
+ if (WARN_ON_ONCE(ipi_send_verify(chip, data, NULL, cpu)))
+ return -EINVAL;
+#endif
+ if (!chip->ipi_send_single) {
+ chip->ipi_send_mask(data, cpumask_of(cpu));
+ return 0;
+ }
+
+ /* FIXME: Store this information in irqdata flags */
+ if (irq_domain_is_ipi_per_cpu(data->domain) &&
+ cpu != data->common->ipi_offset) {
+ /* use the correct data for that cpu */
+ unsigned irq = data->irq + cpu - data->common->ipi_offset;
+
+ data = irq_get_irq_data(irq);
+ }
+ chip->ipi_send_single(data, cpu);
+ return 0;
+}
+
+/**
+ * ipi_send_mask - send an IPI to target Linux SMP CPU(s)
+ * @desc: pointer to irq_desc of the IRQ
+ * @dest: dest CPU(s), must be a subset of the mask passed to
+ * irq_reserve_ipi()
+ *
+ * This function is for architecture or core code to speed up IPI sending. Not
+ * usable from driver code.
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int __ipi_send_mask(struct irq_desc *desc, const struct cpumask *dest)
+{
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+ unsigned int cpu;
+
+#ifdef DEBUG
+ /*
+ * Minimise the overhead by omitting the checks for Linux SMP IPIs.
+ * Since the callers should be arch or core code which is generally
+ * trusted, only check for errors when debugging.
+ */
+ if (WARN_ON_ONCE(ipi_send_verify(chip, data, dest, 0)))
+ return -EINVAL;
+#endif
+ if (chip->ipi_send_mask) {
+ chip->ipi_send_mask(data, dest);
+ return 0;
+ }
+
+ if (irq_domain_is_ipi_per_cpu(data->domain)) {
+ unsigned int base = data->irq;
+
+ for_each_cpu(cpu, dest) {
+ unsigned irq = base + cpu - data->common->ipi_offset;
+
+ data = irq_get_irq_data(irq);
+ chip->ipi_send_single(data, cpu);
+ }
+ } else {
+ for_each_cpu(cpu, dest)
+ chip->ipi_send_single(data, cpu);
+ }
+ return 0;
+}
+
+/**
+ * ipi_send_single - Send an IPI to a single CPU
+ * @virq: linux irq number from irq_reserve_ipi()
+ * @cpu: destination CPU, must in the destination mask passed to
+ * irq_reserve_ipi()
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int ipi_send_single(unsigned int virq, unsigned int cpu)
+{
+ struct irq_desc *desc = irq_to_desc(virq);
+ struct irq_data *data = desc ? irq_desc_get_irq_data(desc) : NULL;
+ struct irq_chip *chip = data ? irq_data_get_irq_chip(data) : NULL;
+
+ if (WARN_ON_ONCE(ipi_send_verify(chip, data, NULL, cpu)))
+ return -EINVAL;
+
+ return __ipi_send_single(desc, cpu);
+}
+EXPORT_SYMBOL_GPL(ipi_send_single);
+
+/**
+ * ipi_send_mask - Send an IPI to target CPU(s)
+ * @virq: linux irq number from irq_reserve_ipi()
+ * @dest: dest CPU(s), must be a subset of the mask passed to
+ * irq_reserve_ipi()
+ *
+ * Returns zero on success and negative error number on failure.
+ */
+int ipi_send_mask(unsigned int virq, const struct cpumask *dest)
+{
+ struct irq_desc *desc = irq_to_desc(virq);
+ struct irq_data *data = desc ? irq_desc_get_irq_data(desc) : NULL;
+ struct irq_chip *chip = data ? irq_data_get_irq_chip(data) : NULL;
+
+ if (WARN_ON_ONCE(ipi_send_verify(chip, data, dest, 0)))
+ return -EINVAL;
+
+ return __ipi_send_mask(desc, dest);
+}
+EXPORT_SYMBOL_GPL(ipi_send_mask);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0409da0bcc33..0ccd028817d7 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -24,10 +24,27 @@
static struct lock_class_key irq_desc_lock_class;
#if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+ cpulist_parse(str, irq_default_affinity);
+ /*
+ * Set at least the boot cpu. We don't want to end up with
+ * bugreports caused by random comandline masks
+ */
+ cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+ return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
static void __init init_irq_default_affinity(void)
{
- alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
- cpumask_setall(irq_default_affinity);
+#ifdef CONFIG_CPUMASK_OFFSTACK
+ if (!irq_default_affinity)
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+#endif
+ if (cpumask_empty(irq_default_affinity))
+ cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3e56d2f03e24..3a519a01118b 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -23,8 +23,6 @@ static DEFINE_MUTEX(irq_domain_mutex);
static DEFINE_MUTEX(revmap_trees_mutex);
static struct irq_domain *irq_default_domain;
-static int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
- irq_hw_number_t hwirq, int node);
static void irq_domain_check_hierarchy(struct irq_domain *domain);
struct irqchip_fwid {
@@ -840,8 +838,8 @@ const struct irq_domain_ops irq_domain_simple_ops = {
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
-static int irq_domain_alloc_descs(int virq, unsigned int cnt,
- irq_hw_number_t hwirq, int node)
+int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
+ int node)
{
unsigned int hint;
@@ -895,6 +893,7 @@ struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
return domain;
}
+EXPORT_SYMBOL_GPL(irq_domain_create_hierarchy);
static void irq_domain_insert_irq(int virq)
{
@@ -1045,6 +1044,7 @@ int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
return 0;
}
+EXPORT_SYMBOL_GPL(irq_domain_set_hwirq_and_chip);
/**
* irq_domain_set_info - Set the complete data for a @virq in @domain
@@ -1078,6 +1078,7 @@ void irq_domain_reset_irq_data(struct irq_data *irq_data)
irq_data->chip = &no_irq_chip;
irq_data->chip_data = NULL;
}
+EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
/**
* irq_domain_free_irqs_common - Clear irq_data and free the parent
@@ -1275,6 +1276,7 @@ int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
nr_irqs, arg);
return -ENOSYS;
}
+EXPORT_SYMBOL_GPL(irq_domain_alloc_irqs_parent);
/**
* irq_domain_free_irqs_parent - Free interrupts from parent domain
@@ -1292,6 +1294,7 @@ void irq_domain_free_irqs_parent(struct irq_domain *domain,
irq_domain_free_irqs_recursive(domain->parent, irq_base,
nr_irqs);
}
+EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent);
/**
* irq_domain_activate_irq - Call domain_ops->activate recursively to activate
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 841187239adc..64731e84c982 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -144,13 +144,11 @@ int irq_can_set_affinity(unsigned int irq)
*/
void irq_set_thread_affinity(struct irq_desc *desc)
{
- struct irqaction *action = desc->action;
+ struct irqaction *action;
- while (action) {
+ for_each_action_of_desc(desc, action)
if (action->thread)
set_bit(IRQTF_AFFINITY, &action->thread_flags);
- action = action->next;
- }
}
#ifdef CONFIG_GENERIC_PENDING_IRQ
@@ -994,7 +992,7 @@ void irq_wake_thread(unsigned int irq, void *dev_id)
return;
raw_spin_lock_irqsave(&desc->lock, flags);
- for (action = desc->action; action; action = action->next) {
+ for_each_action_of_desc(desc, action) {
if (action->dev_id == dev_id) {
if (action->thread)
__irq_wake_thread(desc, action);
@@ -1609,6 +1607,9 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
struct irq_desc *desc;
int retval;
+ if (irq == IRQ_NOTCONNECTED)
+ return -ENOTCONN;
+
/*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
@@ -1699,9 +1700,13 @@ EXPORT_SYMBOL(request_threaded_irq);
int request_any_context_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *name, void *dev_id)
{
- struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_desc *desc;
int ret;
+ if (irq == IRQ_NOTCONNECTED)
+ return -ENOTCONN;
+
+ desc = irq_to_desc(irq);
if (!desc)
return -EINVAL;
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index a2c02fd5d6d0..4e1b94726818 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -291,7 +291,7 @@ static int name_unique(unsigned int irq, struct irqaction *new_action)
int ret = 1;
raw_spin_lock_irqsave(&desc->lock, flags);
- for (action = desc->action ; action; action = action->next) {
+ for_each_action_of_desc(desc, action) {
if ((action != new_action) && action->name &&
!strcmp(new_action->name, action->name)) {
ret = 0;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 32144175458d..5707f97a3e6a 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -211,14 +211,12 @@ static void __report_bad_irq(struct irq_desc *desc, irqreturn_t action_ret)
* desc->lock here. See synchronize_irq().
*/
raw_spin_lock_irqsave(&desc->lock, flags);
- action = desc->action;
- while (action) {
+ for_each_action_of_desc(desc, action) {
printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler);
if (action->thread_fn)
printk(KERN_CONT " threaded [<%p>] %pf",
action->thread_fn, action->thread_fn);
printk(KERN_CONT "\n");
- action = action->next;
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 5c5987f10819..fafd1a3ef0da 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -38,6 +38,7 @@
* during the second link stage.
*/
extern const unsigned long kallsyms_addresses[] __weak;
+extern const int kallsyms_offsets[] __weak;
extern const u8 kallsyms_names[] __weak;
/*
@@ -47,6 +48,9 @@ extern const u8 kallsyms_names[] __weak;
extern const unsigned long kallsyms_num_syms
__attribute__((weak, section(".rodata")));
+extern const unsigned long kallsyms_relative_base
+__attribute__((weak, section(".rodata")));
+
extern const u8 kallsyms_token_table[] __weak;
extern const u16 kallsyms_token_index[] __weak;
@@ -176,6 +180,23 @@ static unsigned int get_symbol_offset(unsigned long pos)
return name - kallsyms_names;
}
+static unsigned long kallsyms_sym_address(int idx)
+{
+ if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
+ return kallsyms_addresses[idx];
+
+ /* values are unsigned offsets if --absolute-percpu is not in effect */
+ if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU))
+ return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
+
+ /* ...otherwise, positive offsets are absolute values */
+ if (kallsyms_offsets[idx] >= 0)
+ return kallsyms_offsets[idx];
+
+ /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
+ return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
+}
+
/* Lookup the address for this symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name)
{
@@ -187,7 +208,7 @@ unsigned long kallsyms_lookup_name(const char *name)
off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
if (strcmp(namebuf, name) == 0)
- return kallsyms_addresses[i];
+ return kallsyms_sym_address(i);
}
return module_kallsyms_lookup_name(name);
}
@@ -204,7 +225,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
- ret = fn(data, namebuf, NULL, kallsyms_addresses[i]);
+ ret = fn(data, namebuf, NULL, kallsyms_sym_address(i));
if (ret != 0)
return ret;
}
@@ -220,7 +241,10 @@ static unsigned long get_symbol_pos(unsigned long addr,
unsigned long i, low, high, mid;
/* This kernel should never had been booted. */
- BUG_ON(!kallsyms_addresses);
+ if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
+ BUG_ON(!kallsyms_addresses);
+ else
+ BUG_ON(!kallsyms_offsets);
/* Do a binary search on the sorted kallsyms_addresses array. */
low = 0;
@@ -228,7 +252,7 @@ static unsigned long get_symbol_pos(unsigned long addr,
while (high - low > 1) {
mid = low + (high - low) / 2;
- if (kallsyms_addresses[mid] <= addr)
+ if (kallsyms_sym_address(mid) <= addr)
low = mid;
else
high = mid;
@@ -238,15 +262,15 @@ static unsigned long get_symbol_pos(unsigned long addr,
* Search for the first aliased symbol. Aliased
* symbols are symbols with the same address.
*/
- while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low])
+ while (low && kallsyms_sym_address(low-1) == kallsyms_sym_address(low))
--low;
- symbol_start = kallsyms_addresses[low];
+ symbol_start = kallsyms_sym_address(low);
/* Search for next non-aliased symbol. */
for (i = low + 1; i < kallsyms_num_syms; i++) {
- if (kallsyms_addresses[i] > symbol_start) {
- symbol_end = kallsyms_addresses[i];
+ if (kallsyms_sym_address(i) > symbol_start) {
+ symbol_end = kallsyms_sym_address(i);
break;
}
}
@@ -470,7 +494,7 @@ static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
unsigned off = iter->nameoff;
iter->module_name[0] = '\0';
- iter->value = kallsyms_addresses[iter->pos];
+ iter->value = kallsyms_sym_address(iter->pos);
iter->type = kallsyms_get_symbol_type(off);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 8dc659144869..8d34308ea449 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -66,13 +66,15 @@ struct resource crashk_res = {
.name = "Crash kernel",
.start = 0,
.end = 0,
- .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+ .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+ .desc = IORES_DESC_CRASH_KERNEL
};
struct resource crashk_low_res = {
.name = "Crash kernel",
.start = 0,
.end = 0,
- .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+ .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+ .desc = IORES_DESC_CRASH_KERNEL
};
int kexec_should_crash(struct task_struct *p)
@@ -959,7 +961,7 @@ int crash_shrink_memory(unsigned long new_size)
ram_res->start = end;
ram_res->end = crashk_res.end;
- ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+ ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
ram_res->name = "System RAM";
crashk_res.end = end - 1;
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b696c3f3708f..c72d2ff5896e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -469,10 +469,10 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
/* Walk the RAM ranges and allocate a suitable range for the buffer */
if (image->type == KEXEC_TYPE_CRASH)
- ret = walk_iomem_res("Crash kernel",
- IORESOURCE_MEM | IORESOURCE_BUSY,
- crashk_res.start, crashk_res.end, kbuf,
- locate_mem_hole_callback);
+ ret = walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+ crashk_res.start, crashk_res.end, kbuf,
+ locate_mem_hole_callback);
else
ret = walk_system_ram_res(0, -1, kbuf,
locate_mem_hole_callback);
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index a02812743a7e..b5c30d9f46c5 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -47,12 +47,12 @@
* of times)
*/
-#include <linux/latencytop.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
#include <linux/notifier.h>
#include <linux/spinlock.h>
#include <linux/proc_fs.h>
+#include <linux/latencytop.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/list.h>
@@ -289,4 +289,16 @@ static int __init init_lstats_procfs(void)
proc_create("latency_stats", 0644, NULL, &lstats_fops);
return 0;
}
+
+int sysctl_latencytop(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ int err;
+
+ err = proc_dointvec(table, write, buffer, lenp, ppos);
+ if (latencytop_enabled)
+ force_schedstat_enabled();
+
+ return err;
+}
device_initcall(init_lstats_procfs);
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 60ace56618f6..53ab2f85d77e 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -123,8 +123,6 @@ static inline int debug_locks_off_graph_unlock(void)
return ret;
}
-static int lockdep_initialized;
-
unsigned long nr_list_entries;
static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
@@ -150,8 +148,7 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
}
#ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
- cpu_lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats);
static inline u64 lockstat_clock(void)
{
@@ -292,7 +289,7 @@ LIST_HEAD(all_lock_classes);
#define __classhashfn(key) hash_long((unsigned long)key, CLASSHASH_BITS)
#define classhashentry(key) (classhash_table + __classhashfn((key)))
-static struct list_head classhash_table[CLASSHASH_SIZE];
+static struct hlist_head classhash_table[CLASSHASH_SIZE];
/*
* We put the lock dependency chains into a hash-table as well, to cache
@@ -303,7 +300,7 @@ static struct list_head classhash_table[CLASSHASH_SIZE];
#define __chainhashfn(chain) hash_long(chain, CHAINHASH_BITS)
#define chainhashentry(chain) (chainhash_table + __chainhashfn((chain)))
-static struct list_head chainhash_table[CHAINHASH_SIZE];
+static struct hlist_head chainhash_table[CHAINHASH_SIZE];
/*
* The hash key of the lock dependency chains is a hash itself too:
@@ -434,19 +431,6 @@ unsigned int max_lockdep_depth;
#ifdef CONFIG_DEBUG_LOCKDEP
/*
- * We cannot printk in early bootup code. Not even early_printk()
- * might work. So we mark any initialization errors and printk
- * about it later on, in lockdep_info().
- */
-static int lockdep_init_error;
-static const char *lock_init_error;
-static unsigned long lockdep_init_trace_data[20];
-static struct stack_trace lockdep_init_trace = {
- .max_entries = ARRAY_SIZE(lockdep_init_trace_data),
- .entries = lockdep_init_trace_data,
-};
-
-/*
* Various lockdep statistics:
*/
DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
@@ -666,23 +650,9 @@ static inline struct lock_class *
look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
{
struct lockdep_subclass_key *key;
- struct list_head *hash_head;
+ struct hlist_head *hash_head;
struct lock_class *class;
-#ifdef CONFIG_DEBUG_LOCKDEP
- /*
- * If the architecture calls into lockdep before initializing
- * the hashes then we'll warn about it later. (we cannot printk
- * right now)
- */
- if (unlikely(!lockdep_initialized)) {
- lockdep_init();
- lockdep_init_error = 1;
- lock_init_error = lock->name;
- save_stack_trace(&lockdep_init_trace);
- }
-#endif
-
if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
debug_locks_off();
printk(KERN_ERR
@@ -719,7 +689,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return NULL;
- list_for_each_entry_rcu(class, hash_head, hash_entry) {
+ hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
if (class->key == key) {
/*
* Huh! same key, different name? Did someone trample
@@ -742,7 +712,7 @@ static inline struct lock_class *
register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
{
struct lockdep_subclass_key *key;
- struct list_head *hash_head;
+ struct hlist_head *hash_head;
struct lock_class *class;
DEBUG_LOCKS_WARN_ON(!irqs_disabled());
@@ -774,7 +744,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
* We have to do the hash-walk again, to avoid races
* with another CPU:
*/
- list_for_each_entry_rcu(class, hash_head, hash_entry) {
+ hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
if (class->key == key)
goto out_unlock_set;
}
@@ -805,7 +775,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
* We use RCU's safe list-add method to make
* parallel walking of the hash-list safe:
*/
- list_add_tail_rcu(&class->hash_entry, hash_head);
+ hlist_add_head_rcu(&class->hash_entry, hash_head);
/*
* Add it to the global list of classes:
*/
@@ -1822,7 +1792,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
*/
static int
check_prev_add(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next, int distance, int trylock_loop)
+ struct held_lock *next, int distance, int *stack_saved)
{
struct lock_list *entry;
int ret;
@@ -1883,8 +1853,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
}
}
- if (!trylock_loop && !save_trace(&trace))
- return 0;
+ if (!*stack_saved) {
+ if (!save_trace(&trace))
+ return 0;
+ *stack_saved = 1;
+ }
/*
* Ok, all validations passed, add the new lock
@@ -1907,6 +1880,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
* Debugging printouts:
*/
if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
+ /* We drop graph lock, so another thread can overwrite trace. */
+ *stack_saved = 0;
graph_unlock();
printk("\n new dependency: ");
print_lock_name(hlock_class(prev));
@@ -1929,7 +1904,7 @@ static int
check_prevs_add(struct task_struct *curr, struct held_lock *next)
{
int depth = curr->lockdep_depth;
- int trylock_loop = 0;
+ int stack_saved = 0;
struct held_lock *hlock;
/*
@@ -1956,7 +1931,7 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
*/
if (hlock->read != 2 && hlock->check) {
if (!check_prev_add(curr, hlock, next,
- distance, trylock_loop))
+ distance, &stack_saved))
return 0;
/*
* Stop after the first non-trylock entry,
@@ -1979,7 +1954,6 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
if (curr->held_locks[depth].irq_context !=
curr->held_locks[depth-1].irq_context)
break;
- trylock_loop = 1;
}
return 1;
out_bug:
@@ -2007,6 +1981,53 @@ struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
}
/*
+ * Returns the index of the first held_lock of the current chain
+ */
+static inline int get_first_held_lock(struct task_struct *curr,
+ struct held_lock *hlock)
+{
+ int i;
+ struct held_lock *hlock_curr;
+
+ for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+ hlock_curr = curr->held_locks + i;
+ if (hlock_curr->irq_context != hlock->irq_context)
+ break;
+
+ }
+
+ return ++i;
+}
+
+/*
+ * Checks whether the chain and the current held locks are consistent
+ * in depth and also in content. If they are not it most likely means
+ * that there was a collision during the calculation of the chain_key.
+ * Returns: 0 not passed, 1 passed
+ */
+static int check_no_collision(struct task_struct *curr,
+ struct held_lock *hlock,
+ struct lock_chain *chain)
+{
+#ifdef CONFIG_DEBUG_LOCKDEP
+ int i, j, id;
+
+ i = get_first_held_lock(curr, hlock);
+
+ if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1)))
+ return 0;
+
+ for (j = 0; j < chain->depth - 1; j++, i++) {
+ id = curr->held_locks[i].class_idx - 1;
+
+ if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id))
+ return 0;
+ }
+#endif
+ return 1;
+}
+
+/*
* Look up a dependency chain. If the key is not present yet then
* add it and return 1 - in this case the new dependency chain is
* validated. If the key is already hashed, return 0.
@@ -2017,9 +2038,8 @@ static inline int lookup_chain_cache(struct task_struct *curr,
u64 chain_key)
{
struct lock_class *class = hlock_class(hlock);
- struct list_head *hash_head = chainhashentry(chain_key);
+ struct hlist_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
- struct held_lock *hlock_curr;
int i, j;
/*
@@ -2033,10 +2053,13 @@ static inline int lookup_chain_cache(struct task_struct *curr,
* We can walk it lock-free, because entries only get added
* to the hash:
*/
- list_for_each_entry_rcu(chain, hash_head, entry) {
+ hlist_for_each_entry_rcu(chain, hash_head, entry) {
if (chain->chain_key == chain_key) {
cache_hit:
debug_atomic_inc(chain_lookup_hits);
+ if (!check_no_collision(curr, hlock, chain))
+ return 0;
+
if (very_verbose(class))
printk("\nhash chain already cached, key: "
"%016Lx tail class: [%p] %s\n",
@@ -2057,7 +2080,7 @@ cache_hit:
/*
* We have to walk the chain again locked - to avoid duplicates:
*/
- list_for_each_entry(chain, hash_head, entry) {
+ hlist_for_each_entry(chain, hash_head, entry) {
if (chain->chain_key == chain_key) {
graph_unlock();
goto cache_hit;
@@ -2074,13 +2097,7 @@ cache_hit:
chain = lock_chains + nr_lock_chains++;
chain->chain_key = chain_key;
chain->irq_context = hlock->irq_context;
- /* Find the first held_lock of current chain */
- for (i = curr->lockdep_depth - 1; i >= 0; i--) {
- hlock_curr = curr->held_locks + i;
- if (hlock_curr->irq_context != hlock->irq_context)
- break;
- }
- i++;
+ i = get_first_held_lock(curr, hlock);
chain->depth = curr->lockdep_depth + 1 - i;
if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
chain->base = nr_chain_hlocks;
@@ -2091,7 +2108,7 @@ cache_hit:
}
chain_hlocks[chain->base + j] = class - lock_classes;
}
- list_add_tail_rcu(&chain->entry, hash_head);
+ hlist_add_head_rcu(&chain->entry, hash_head);
debug_atomic_inc(chain_lookup_misses);
inc_chains();
@@ -2168,7 +2185,7 @@ static void check_chain_key(struct task_struct *curr)
{
#ifdef CONFIG_DEBUG_LOCKDEP
struct held_lock *hlock, *prev_hlock = NULL;
- unsigned int i, id;
+ unsigned int i;
u64 chain_key = 0;
for (i = 0; i < curr->lockdep_depth; i++) {
@@ -2185,17 +2202,16 @@ static void check_chain_key(struct task_struct *curr)
(unsigned long long)hlock->prev_chain_key);
return;
}
- id = hlock->class_idx - 1;
/*
* Whoops ran out of static storage again?
*/
- if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+ if (DEBUG_LOCKS_WARN_ON(hlock->class_idx > MAX_LOCKDEP_KEYS))
return;
if (prev_hlock && (prev_hlock->irq_context !=
hlock->irq_context))
chain_key = 0;
- chain_key = iterate_chain_key(chain_key, id);
+ chain_key = iterate_chain_key(chain_key, hlock->class_idx);
prev_hlock = hlock;
}
if (chain_key != curr->curr_chain_key) {
@@ -3073,7 +3089,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
struct task_struct *curr = current;
struct lock_class *class = NULL;
struct held_lock *hlock;
- unsigned int depth, id;
+ unsigned int depth;
int chain_head = 0;
int class_idx;
u64 chain_key;
@@ -3176,11 +3192,10 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
* The 'key ID' is what is the most compact key value to drive
* the hash, not class->key.
*/
- id = class - lock_classes;
/*
* Whoops, we did it again.. ran straight out of our static allocation.
*/
- if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+ if (DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS))
return 0;
chain_key = curr->curr_chain_key;
@@ -3198,7 +3213,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
chain_key = 0;
chain_head = 1;
}
- chain_key = iterate_chain_key(chain_key, id);
+ chain_key = iterate_chain_key(chain_key, class_idx);
if (nest_lock && !__lock_is_held(nest_lock))
return print_lock_nested_lock_not_held(curr, hlock, ip);
@@ -3875,7 +3890,7 @@ void lockdep_reset(void)
nr_process_chains = 0;
debug_locks = 1;
for (i = 0; i < CHAINHASH_SIZE; i++)
- INIT_LIST_HEAD(chainhash_table + i);
+ INIT_HLIST_HEAD(chainhash_table + i);
raw_local_irq_restore(flags);
}
@@ -3894,7 +3909,7 @@ static void zap_class(struct lock_class *class)
/*
* Unhash the class and remove it from the all_lock_classes list:
*/
- list_del_rcu(&class->hash_entry);
+ hlist_del_rcu(&class->hash_entry);
list_del_rcu(&class->lock_entry);
RCU_INIT_POINTER(class->key, NULL);
@@ -3917,7 +3932,7 @@ static inline int within(const void *addr, void *start, unsigned long size)
void lockdep_free_key_range(void *start, unsigned long size)
{
struct lock_class *class;
- struct list_head *head;
+ struct hlist_head *head;
unsigned long flags;
int i;
int locked;
@@ -3930,9 +3945,7 @@ void lockdep_free_key_range(void *start, unsigned long size)
*/
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
- if (list_empty(head))
- continue;
- list_for_each_entry_rcu(class, head, hash_entry) {
+ hlist_for_each_entry_rcu(class, head, hash_entry) {
if (within(class->key, start, size))
zap_class(class);
else if (within(class->name, start, size))
@@ -3962,7 +3975,7 @@ void lockdep_free_key_range(void *start, unsigned long size)
void lockdep_reset_lock(struct lockdep_map *lock)
{
struct lock_class *class;
- struct list_head *head;
+ struct hlist_head *head;
unsigned long flags;
int i, j;
int locked;
@@ -3987,9 +4000,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
locked = graph_lock();
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
- if (list_empty(head))
- continue;
- list_for_each_entry_rcu(class, head, hash_entry) {
+ hlist_for_each_entry_rcu(class, head, hash_entry) {
int match = 0;
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
@@ -4013,28 +4024,6 @@ out_restore:
raw_local_irq_restore(flags);
}
-void lockdep_init(void)
-{
- int i;
-
- /*
- * Some architectures have their own start_kernel()
- * code which calls lockdep_init(), while we also
- * call lockdep_init() from the start_kernel() itself,
- * and we want to initialize the hashes only once:
- */
- if (lockdep_initialized)
- return;
-
- for (i = 0; i < CLASSHASH_SIZE; i++)
- INIT_LIST_HEAD(classhash_table + i);
-
- for (i = 0; i < CHAINHASH_SIZE; i++)
- INIT_LIST_HEAD(chainhash_table + i);
-
- lockdep_initialized = 1;
-}
-
void __init lockdep_info(void)
{
printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
@@ -4061,14 +4050,6 @@ void __init lockdep_info(void)
printk(" per task-struct memory footprint: %lu bytes\n",
sizeof(struct held_lock) * MAX_LOCK_DEPTH);
-
-#ifdef CONFIG_DEBUG_LOCKDEP
- if (lockdep_init_error) {
- printk("WARNING: lockdep init error: lock '%s' was acquired before lockdep_init().\n", lock_init_error);
- printk("Call stack leading to lockdep invocation was:\n");
- print_stack_trace(&lockdep_init_trace, 0);
- }
-#endif
}
static void
diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index 5b9102a47ea5..c835270f0c2f 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/kernel/locking/mcs_spinlock.h
@@ -67,7 +67,13 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
node->locked = 0;
node->next = NULL;
- prev = xchg_acquire(lock, node);
+ /*
+ * We rely on the full barrier with global transitivity implied by the
+ * below xchg() to order the initialization stores above against any
+ * observation of @node. And to provide the ACQUIRE ordering associated
+ * with a LOCK primitive.
+ */
+ prev = xchg(lock, node);
if (likely(prev == NULL)) {
/*
* Lock acquired, don't need to set node->locked to 1. Threads
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 0551c219c40e..e364b424b019 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -716,6 +716,7 @@ static inline void
__mutex_unlock_common_slowpath(struct mutex *lock, int nested)
{
unsigned long flags;
+ WAKE_Q(wake_q);
/*
* As a performance measurement, release the lock before doing other
@@ -743,11 +744,11 @@ __mutex_unlock_common_slowpath(struct mutex *lock, int nested)
struct mutex_waiter, list);
debug_mutex_wake_waiter(lock, waiter);
-
- wake_up_process(waiter->task);
+ wake_q_add(&wake_q, waiter->task);
}
spin_unlock_mutex(&lock->wait_lock, flags);
+ wake_up_q(&wake_q);
}
/*
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 393d1874b9e0..ce2f75e32ae1 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -358,8 +358,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
* sequentiality; this is because not all clear_pending_set_locked()
* implementations imply full barriers.
*/
- while ((val = smp_load_acquire(&lock->val.counter)) & _Q_LOCKED_MASK)
- cpu_relax();
+ smp_cond_acquire(!(atomic_read(&lock->val) & _Q_LOCKED_MASK));
/*
* take ownership and clear the pending bit.
@@ -435,7 +434,7 @@ queue:
*
* The PV pv_wait_head_or_lock function, if active, will acquire
* the lock and return a non-zero value. So we have to skip the
- * smp_load_acquire() call. As the next PV queue head hasn't been
+ * smp_cond_acquire() call. As the next PV queue head hasn't been
* designated yet, there is no way for the locked value to become
* _Q_SLOW_VAL. So both the set_locked() and the
* atomic_cmpxchg_relaxed() calls will be safe.
@@ -466,7 +465,7 @@ locked:
break;
}
/*
- * The smp_load_acquire() call above has provided the necessary
+ * The smp_cond_acquire() call above has provided the necessary
* acquire semantics required for locking. At most two
* iterations of this loop may be ran.
*/
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 87bb235c3448..21ede57f68b3 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -55,6 +55,11 @@ struct pv_node {
};
/*
+ * Include queued spinlock statistics code
+ */
+#include "qspinlock_stat.h"
+
+/*
* By replacing the regular queued_spin_trylock() with the function below,
* it will be called once when a lock waiter enter the PV slowpath before
* being queued. By allowing one lock stealing attempt here when the pending
@@ -65,9 +70,11 @@ struct pv_node {
static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock)
{
struct __qspinlock *l = (void *)lock;
+ int ret = !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) &&
+ (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0);
- return !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) &&
- (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0);
+ qstat_inc(qstat_pv_lock_stealing, ret);
+ return ret;
}
/*
@@ -138,11 +145,6 @@ static __always_inline int trylock_clear_pending(struct qspinlock *lock)
#endif /* _Q_PENDING_BITS == 8 */
/*
- * Include queued spinlock statistics code
- */
-#include "qspinlock_stat.h"
-
-/*
* Lock and MCS node addresses hash table for fast lookup
*
* Hashing is done on a per-cacheline basis to minimize the need to access
@@ -398,6 +400,11 @@ pv_wait_head_or_lock(struct qspinlock *lock, struct mcs_spinlock *node)
if (READ_ONCE(pn->state) == vcpu_hashed)
lp = (struct qspinlock **)1;
+ /*
+ * Tracking # of slowpath locking operations
+ */
+ qstat_inc(qstat_pv_lock_slowpath, true);
+
for (;; waitcnt++) {
/*
* Set correct vCPU state to be used by queue node wait-early
diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 640dcecdd1df..eb2a2c9bc3fc 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -22,6 +22,7 @@
* pv_kick_wake - # of vCPU kicks used for computing pv_latency_wake
* pv_latency_kick - average latency (ns) of vCPU kick operation
* pv_latency_wake - average latency (ns) from vCPU kick to wakeup
+ * pv_lock_slowpath - # of locking operations via the slowpath
* pv_lock_stealing - # of lock stealing operations
* pv_spurious_wakeup - # of spurious wakeups
* pv_wait_again - # of vCPU wait's that happened after a vCPU kick
@@ -45,6 +46,7 @@ enum qlock_stats {
qstat_pv_kick_wake,
qstat_pv_latency_kick,
qstat_pv_latency_wake,
+ qstat_pv_lock_slowpath,
qstat_pv_lock_stealing,
qstat_pv_spurious_wakeup,
qstat_pv_wait_again,
@@ -70,6 +72,7 @@ static const char * const qstat_names[qstat_num + 1] = {
[qstat_pv_spurious_wakeup] = "pv_spurious_wakeup",
[qstat_pv_latency_kick] = "pv_latency_kick",
[qstat_pv_latency_wake] = "pv_latency_wake",
+ [qstat_pv_lock_slowpath] = "pv_lock_slowpath",
[qstat_pv_lock_stealing] = "pv_lock_stealing",
[qstat_pv_wait_again] = "pv_wait_again",
[qstat_pv_wait_early] = "pv_wait_early",
@@ -279,19 +282,6 @@ static inline void __pv_wait(u8 *ptr, u8 val)
#define pv_kick(c) __pv_kick(c)
#define pv_wait(p, v) __pv_wait(p, v)
-/*
- * PV unfair trylock count tracking function
- */
-static inline int qstat_spin_steal_lock(struct qspinlock *lock)
-{
- int ret = pv_queued_spin_steal_lock(lock);
-
- qstat_inc(qstat_pv_lock_stealing, ret);
- return ret;
-}
-#undef queued_spin_trylock
-#define queued_spin_trylock(l) qstat_spin_steal_lock(l)
-
#else /* CONFIG_QUEUED_LOCK_STAT */
static inline void qstat_inc(enum qlock_stats stat, bool cond) { }
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 70ee3775de24..584febd13e2e 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -29,10 +29,10 @@ __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
static void *try_ram_remap(resource_size_t offset, size_t size)
{
- struct page *page = pfn_to_page(offset >> PAGE_SHIFT);
+ unsigned long pfn = PHYS_PFN(offset);
/* In the simple case just return the existing linear address */
- if (!PageHighMem(page))
+ if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)))
return __va(offset);
return NULL; /* fallback to ioremap_cache */
}
@@ -47,7 +47,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size)
* being mapped does not have i/o side effects and the __iomem
* annotation is not applicable.
*
- * MEMREMAP_WB - matches the default mapping for "System RAM" on
+ * MEMREMAP_WB - matches the default mapping for System RAM on
* the architecture. This is usually a read-allocate write-back cache.
* Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
* memremap() will bypass establishing a new mapping and instead return
@@ -56,11 +56,12 @@ static void *try_ram_remap(resource_size_t offset, size_t size)
* MEMREMAP_WT - establish a mapping whereby writes either bypass the
* cache or are written through to memory and never exist in a
* cache-dirty state with respect to program visibility. Attempts to
- * map "System RAM" with this mapping type will fail.
+ * map System RAM with this mapping type will fail.
*/
void *memremap(resource_size_t offset, size_t size, unsigned long flags)
{
- int is_ram = region_intersects(offset, size, "System RAM");
+ int is_ram = region_intersects(offset, size,
+ IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
void *addr = NULL;
if (is_ram == REGION_MIXED) {
@@ -76,7 +77,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
* MEMREMAP_WB is special in that it can be satisifed
* from the direct map. Some archs depend on the
* capability of memremap() to autodetect cases where
- * the requested range is potentially in "System RAM"
+ * the requested range is potentially in System RAM.
*/
if (is_ram == REGION_INTERSECTS)
addr = try_ram_remap(offset, size);
@@ -88,7 +89,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
* If we don't have a mapping yet and more request flags are
* pending then we will be attempting to establish a new virtual
* address mapping. Enforce that this mapping is not aliasing
- * "System RAM"
+ * System RAM.
*/
if (!addr && is_ram == REGION_INTERSECTS && flags) {
WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
@@ -114,7 +115,7 @@ EXPORT_SYMBOL(memunmap);
static void devm_memremap_release(struct device *dev, void *res)
{
- memunmap(res);
+ memunmap(*(void **)res);
}
static int devm_memremap_match(struct device *dev, void *res, void *match_data)
@@ -136,8 +137,10 @@ void *devm_memremap(struct device *dev, resource_size_t offset,
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
- } else
+ } else {
devres_free(ptr);
+ return ERR_PTR(-ENXIO);
+ }
return addr;
}
@@ -150,7 +153,7 @@ void devm_memunmap(struct device *dev, void *addr)
}
EXPORT_SYMBOL(devm_memunmap);
-pfn_t phys_to_pfn_t(phys_addr_t addr, unsigned long flags)
+pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags)
{
return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
}
@@ -268,13 +271,17 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
void *devm_memremap_pages(struct device *dev, struct resource *res,
struct percpu_ref *ref, struct vmem_altmap *altmap)
{
- int is_ram = region_intersects(res->start, resource_size(res),
- "System RAM");
resource_size_t key, align_start, align_size, align_end;
struct dev_pagemap *pgmap;
struct page_map *page_map;
+ int error, nid, is_ram;
unsigned long pfn;
- int error, nid;
+
+ align_start = res->start & ~(SECTION_SIZE - 1);
+ align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
+ - align_start;
+ is_ram = region_intersects(align_start, align_size,
+ IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
if (is_ram == REGION_MIXED) {
WARN_ONCE(1, "%s attempted on mixed region %pr\n",
@@ -312,8 +319,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
mutex_lock(&pgmap_lock);
error = 0;
- align_start = res->start & ~(SECTION_SIZE - 1);
- align_size = ALIGN(resource_size(res), SECTION_SIZE);
align_end = align_start + align_size - 1;
for (key = align_start; key <= align_end; key += SECTION_SIZE) {
struct dev_pagemap *dup;
@@ -349,8 +354,13 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
for_each_device_pfn(pfn, page_map) {
struct page *page = pfn_to_page(pfn);
- /* ZONE_DEVICE pages must never appear on a slab lru */
- list_force_poison(&page->lru);
+ /*
+ * ZONE_DEVICE pages union ->lru with a ->pgmap back
+ * pointer. It is a bug if a ZONE_DEVICE page is ever
+ * freed or placed on a driver-private list. Seed the
+ * storage with LIST_POISON* values.
+ */
+ list_del(&page->lru);
page->pgmap = pgmap;
}
devres_add(dev, page_map);
@@ -381,7 +391,7 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
/*
* 'memmap_start' is the virtual address for the first "struct
* page" in this range of the vmemmap array. In the case of
- * CONFIG_SPARSE_VMEMMAP a page_to_pfn conversion is simple
+ * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple
* pointer arithmetic, so we can perform this to_vmem_altmap()
* conversion without concern for the initialization state of
* the struct page fields.
@@ -390,7 +400,7 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
struct dev_pagemap *pgmap;
/*
- * Uncoditionally retrieve a dev_pagemap associated with the
+ * Unconditionally retrieve a dev_pagemap associated with the
* given physical address, this is only for use in the
* arch_{add|remove}_memory() for setting up and tearing down
* the memmap.
diff --git a/kernel/module.c b/kernel/module.c
index 955410928696..87cfeb25cf65 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -303,6 +303,9 @@ struct load_info {
struct _ddebug *debug;
unsigned int num_debug;
bool sig_ok;
+#ifdef CONFIG_KALLSYMS
+ unsigned long mod_kallsyms_init_off;
+#endif
struct {
unsigned int sym, str, mod, vers, info, pcpu;
} index;
@@ -981,6 +984,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
mod->exit();
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
+ ftrace_release_mod(mod);
+
async_synchronize_full();
/* Store the name of the last unloaded module for diagnostic purposes */
@@ -2480,10 +2485,21 @@ static void layout_symtab(struct module *mod, struct load_info *info)
strsect->sh_flags |= SHF_ALLOC;
strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
info->index.str) | INIT_OFFSET_MASK;
- mod->init_layout.size = debug_align(mod->init_layout.size);
pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
+
+ /* We'll tack temporary mod_kallsyms on the end. */
+ mod->init_layout.size = ALIGN(mod->init_layout.size,
+ __alignof__(struct mod_kallsyms));
+ info->mod_kallsyms_init_off = mod->init_layout.size;
+ mod->init_layout.size += sizeof(struct mod_kallsyms);
+ mod->init_layout.size = debug_align(mod->init_layout.size);
}
+/*
+ * We use the full symtab and strtab which layout_symtab arranged to
+ * be appended to the init section. Later we switch to the cut-down
+ * core-only ones.
+ */
static void add_kallsyms(struct module *mod, const struct load_info *info)
{
unsigned int i, ndst;
@@ -2492,29 +2508,34 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
char *s;
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
- mod->symtab = (void *)symsec->sh_addr;
- mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+ /* Set up to point into init section. */
+ mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
+
+ mod->kallsyms->symtab = (void *)symsec->sh_addr;
+ mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
/* Make sure we get permanent strtab: don't use info->strtab. */
- mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+ mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
/* Set types up while we still have access to sections. */
- for (i = 0; i < mod->num_symtab; i++)
- mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
-
- mod->core_symtab = dst = mod->core_layout.base + info->symoffs;
- mod->core_strtab = s = mod->core_layout.base + info->stroffs;
- src = mod->symtab;
- for (ndst = i = 0; i < mod->num_symtab; i++) {
+ for (i = 0; i < mod->kallsyms->num_symtab; i++)
+ mod->kallsyms->symtab[i].st_info
+ = elf_type(&mod->kallsyms->symtab[i], info);
+
+ /* Now populate the cut down core kallsyms for after init. */
+ mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
+ mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
+ src = mod->kallsyms->symtab;
+ for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
if (i == 0 ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
dst[ndst] = src[i];
- dst[ndst++].st_name = s - mod->core_strtab;
- s += strlcpy(s, &mod->strtab[src[i].st_name],
+ dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
+ s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
KSYM_NAME_LEN) + 1;
}
}
- mod->core_num_syms = ndst;
+ mod->core_kallsyms.num_symtab = ndst;
}
#else
static inline void layout_symtab(struct module *mod, struct load_info *info)
@@ -3206,9 +3227,8 @@ static noinline int do_init_module(struct module *mod)
module_put(mod);
trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
- mod->num_symtab = mod->core_num_syms;
- mod->symtab = mod->core_symtab;
- mod->strtab = mod->core_strtab;
+ /* Switch to core kallsyms now init is done: kallsyms may be walking! */
+ rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
#endif
mod_tree_remove_init(mod);
disable_ro_nx(&mod->init_layout);
@@ -3238,6 +3258,7 @@ fail:
module_put(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
+ ftrace_release_mod(mod);
free_module(mod);
wake_up_all(&module_wq);
return ret;
@@ -3314,6 +3335,7 @@ static int complete_formation(struct module *mod, struct load_info *info)
mod->state = MODULE_STATE_COMING;
mutex_unlock(&module_mutex);
+ ftrace_module_enable(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
return 0;
@@ -3439,7 +3461,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
/* Module is ready to execute: parsing args may do that. */
after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
- -32768, 32767, NULL,
+ -32768, 32767, mod,
unknown_module_param_cb);
if (IS_ERR(after_dashes)) {
err = PTR_ERR(after_dashes);
@@ -3575,6 +3597,11 @@ static inline int is_arm_mapping_symbol(const char *str)
&& (str[2] == '\0' || str[2] == '.');
}
+static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
+{
+ return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
+}
+
static const char *get_ksymbol(struct module *mod,
unsigned long addr,
unsigned long *size,
@@ -3582,6 +3609,7 @@ static const char *get_ksymbol(struct module *mod,
{
unsigned int i, best = 0;
unsigned long nextval;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
/* At worse, next value is at end of module */
if (within_module_init(addr, mod))
@@ -3591,32 +3619,32 @@ static const char *get_ksymbol(struct module *mod,
/* Scan for closest preceding symbol, and next symbol. (ELF
starts real symbols at 1). */
- for (i = 1; i < mod->num_symtab; i++) {
- if (mod->symtab[i].st_shndx == SHN_UNDEF)
+ for (i = 1; i < kallsyms->num_symtab; i++) {
+ if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
continue;
/* We ignore unnamed symbols: they're uninformative
* and inserted at a whim. */
- if (mod->symtab[i].st_value <= addr
- && mod->symtab[i].st_value > mod->symtab[best].st_value
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
+ if (*symname(kallsyms, i) == '\0'
+ || is_arm_mapping_symbol(symname(kallsyms, i)))
+ continue;
+
+ if (kallsyms->symtab[i].st_value <= addr
+ && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
best = i;
- if (mod->symtab[i].st_value > addr
- && mod->symtab[i].st_value < nextval
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
- nextval = mod->symtab[i].st_value;
+ if (kallsyms->symtab[i].st_value > addr
+ && kallsyms->symtab[i].st_value < nextval)
+ nextval = kallsyms->symtab[i].st_value;
}
if (!best)
return NULL;
if (size)
- *size = nextval - mod->symtab[best].st_value;
+ *size = nextval - kallsyms->symtab[best].st_value;
if (offset)
- *offset = addr - mod->symtab[best].st_value;
- return mod->strtab + mod->symtab[best].st_name;
+ *offset = addr - kallsyms->symtab[best].st_value;
+ return symname(kallsyms, best);
}
/* For kallsyms to ask for address resolution. NULL means not found. Careful
@@ -3706,19 +3734,21 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ struct mod_kallsyms *kallsyms;
+
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- if (symnum < mod->num_symtab) {
- *value = mod->symtab[symnum].st_value;
- *type = mod->symtab[symnum].st_info;
- strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
- KSYM_NAME_LEN);
+ kallsyms = rcu_dereference_sched(mod->kallsyms);
+ if (symnum < kallsyms->num_symtab) {
+ *value = kallsyms->symtab[symnum].st_value;
+ *type = kallsyms->symtab[symnum].st_info;
+ strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, *value, mod);
preempt_enable();
return 0;
}
- symnum -= mod->num_symtab;
+ symnum -= kallsyms->num_symtab;
}
preempt_enable();
return -ERANGE;
@@ -3727,11 +3757,12 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
static unsigned long mod_find_symname(struct module *mod, const char *name)
{
unsigned int i;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
- for (i = 0; i < mod->num_symtab; i++)
- if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
- mod->symtab[i].st_info != 'U')
- return mod->symtab[i].st_value;
+ for (i = 0; i < kallsyms->num_symtab; i++)
+ if (strcmp(name, symname(kallsyms, i)) == 0 &&
+ kallsyms->symtab[i].st_info != 'U')
+ return kallsyms->symtab[i].st_value;
return 0;
}
@@ -3770,11 +3801,14 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
module_assert_mutex();
list_for_each_entry(mod, &modules, list) {
+ /* We hold module_mutex: no need for rcu_dereference_sched */
+ struct mod_kallsyms *kallsyms = mod->kallsyms;
+
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- for (i = 0; i < mod->num_symtab; i++) {
- ret = fn(data, mod->strtab + mod->symtab[i].st_name,
- mod, mod->symtab[i].st_value);
+ for (i = 0; i < kallsyms->num_symtab; i++) {
+ ret = fn(data, symname(kallsyms, i),
+ mod, kallsyms->symtab[i].st_value);
if (ret != 0)
return ret;
}
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index b7342a24f559..aa0f26b58426 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1158,6 +1158,22 @@ static int __init kaslr_nohibernate_setup(char *str)
return nohibernate_setup(str);
}
+static int __init page_poison_nohibernate_setup(char *str)
+{
+#ifdef CONFIG_PAGE_POISONING_ZERO
+ /*
+ * The zeroing option for page poison skips the checks on alloc.
+ * since hibernation doesn't save free pages there's no way to
+ * guarantee the pages will still be zeroed.
+ */
+ if (!strcmp(str, "on")) {
+ pr_info("Disabling hibernation due to page poisoning\n");
+ return nohibernate_setup(str);
+ }
+#endif
+ return 1;
+}
+
__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);
@@ -1166,3 +1182,4 @@ __setup("resumewait", resumewait_setup);
__setup("resumedelay=", resumedelay_setup);
__setup("nohibernate", nohibernate_setup);
__setup("kaslr", kaslr_nohibernate_setup);
+__setup("page_poison=", page_poison_nohibernate_setup);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 564f786df470..df058bed53ce 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -30,13 +30,12 @@ static int try_to_freeze_tasks(bool user_only)
unsigned long end_time;
unsigned int todo;
bool wq_busy = false;
- struct timeval start, end;
- u64 elapsed_msecs64;
+ ktime_t start, end, elapsed;
unsigned int elapsed_msecs;
bool wakeup = false;
int sleep_usecs = USEC_PER_MSEC;
- do_gettimeofday(&start);
+ start = ktime_get_boottime();
end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
@@ -78,10 +77,9 @@ static int try_to_freeze_tasks(bool user_only)
sleep_usecs *= 2;
}
- do_gettimeofday(&end);
- elapsed_msecs64 = timeval_to_ns(&end) - timeval_to_ns(&start);
- do_div(elapsed_msecs64, NSEC_PER_MSEC);
- elapsed_msecs = elapsed_msecs64;
+ end = ktime_get_boottime();
+ elapsed = ktime_sub(end, start);
+ elapsed_msecs = ktime_to_ms(elapsed);
if (todo) {
pr_cont("\n");
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index f9fe133c13e2..230a77225e2e 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -248,7 +248,7 @@ static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
if (pm_test_level == level) {
- printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
+ pr_info("suspend debug: Waiting for %d second(s).\n",
pm_test_delay);
mdelay(pm_test_delay * 1000);
return 1;
@@ -320,7 +320,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
error = dpm_suspend_late(PMSG_SUSPEND);
if (error) {
- printk(KERN_ERR "PM: late suspend of devices failed\n");
+ pr_err("PM: late suspend of devices failed\n");
goto Platform_finish;
}
error = platform_suspend_prepare_late(state);
@@ -329,7 +329,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
- printk(KERN_ERR "PM: noirq suspend of devices failed\n");
+ pr_err("PM: noirq suspend of devices failed\n");
goto Platform_early_resume;
}
error = platform_suspend_prepare_noirq(state);
diff --git a/kernel/profile.c b/kernel/profile.c
index 99513e1160e5..51369697466e 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -59,6 +59,7 @@ int profile_setup(char *str)
if (!strncmp(str, sleepstr, strlen(sleepstr))) {
#ifdef CONFIG_SCHEDSTATS
+ force_schedstat_enabled();
prof_on = SLEEP_PROFILING;
if (str[strlen(sleepstr)] == ',')
str += strlen(sleepstr) + 1;
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d2988d047d66..250ea67c1615 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -130,10 +130,8 @@ static struct rcu_torture __rcu *rcu_torture_current;
static unsigned long rcu_torture_current_version;
static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
static DEFINE_SPINLOCK(rcu_torture_lock);
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
- rcu_torture_count) = { 0 };
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
- rcu_torture_batch) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = { 0 };
static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
static atomic_t n_rcu_torture_alloc;
static atomic_t n_rcu_torture_alloc_fail;
@@ -932,12 +930,14 @@ rcu_torture_writer(void *arg)
int nsynctypes = 0;
VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
- pr_alert("%s" TORTURE_FLAG
- " Grace periods expedited from boot/sysfs for %s,\n",
- torture_type, cur_ops->name);
- pr_alert("%s" TORTURE_FLAG
- " Testing of dynamic grace-period expediting diabled.\n",
- torture_type);
+ if (!can_expedite) {
+ pr_alert("%s" TORTURE_FLAG
+ " Grace periods expedited from boot/sysfs for %s,\n",
+ torture_type, cur_ops->name);
+ pr_alert("%s" TORTURE_FLAG
+ " Disabled dynamic grace-period expediting.\n",
+ torture_type);
+ }
/* Initialize synctype[] array. If none set, take default. */
if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
diff --git a/kernel/rcu/tiny_plugin.h b/kernel/rcu/tiny_plugin.h
index e492a5253e0f..196f0302e2f4 100644
--- a/kernel/rcu/tiny_plugin.h
+++ b/kernel/rcu/tiny_plugin.h
@@ -23,7 +23,7 @@
*/
#include <linux/kthread.h>
-#include <linux/module.h>
+#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
@@ -122,18 +122,7 @@ free_out:
debugfs_remove_recursive(rcudir);
return 1;
}
-
-static void __exit rcutiny_trace_cleanup(void)
-{
- debugfs_remove_recursive(rcudir);
-}
-
-module_init(rcutiny_trace_init);
-module_exit(rcutiny_trace_cleanup);
-
-MODULE_AUTHOR("Paul E. McKenney");
-MODULE_DESCRIPTION("Read-Copy Update tracing for tiny implementation");
-MODULE_LICENSE("GPL");
+device_initcall(rcutiny_trace_init);
static void check_cpu_stall(struct rcu_ctrlblk *rcp)
{
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e41dd4131f7a..9a535a86e732 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -108,7 +108,6 @@ RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
static struct rcu_state *const rcu_state_p;
-static struct rcu_data __percpu *const rcu_data_p;
LIST_HEAD(rcu_struct_flavors);
/* Dump rcu_node combining tree at boot to verify correct setup. */
@@ -1083,13 +1082,12 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp,
rcu_sysidle_check_cpu(rdp, isidle, maxj);
if ((rdp->dynticks_snap & 0x1) == 0) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
- return 1;
- } else {
if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4,
rdp->mynode->gpnum))
WRITE_ONCE(rdp->gpwrap, true);
- return 0;
+ return 1;
}
+ return 0;
}
/*
@@ -1173,15 +1171,16 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
smp_mb(); /* ->cond_resched_completed before *rcrmp. */
WRITE_ONCE(*rcrmp,
READ_ONCE(*rcrmp) + rdp->rsp->flavor_mask);
- resched_cpu(rdp->cpu); /* Force CPU into scheduler. */
- rdp->rsp->jiffies_resched += 5; /* Enable beating. */
- } else if (ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
- /* Time to beat on that CPU again! */
- resched_cpu(rdp->cpu); /* Force CPU into scheduler. */
- rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
}
+ rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
}
+ /* And if it has been a really long time, kick the CPU as well. */
+ if (ULONG_CMP_GE(jiffies,
+ rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) ||
+ ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs))
+ resched_cpu(rdp->cpu); /* Force CPU into scheduler. */
+
return 0;
}
@@ -1246,7 +1245,7 @@ static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
if (rnp->qsmask & (1UL << cpu))
dump_cpu_task(rnp->grplo + cpu);
}
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
@@ -1266,12 +1265,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
delta = jiffies - READ_ONCE(rsp->jiffies_stall);
if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
WRITE_ONCE(rsp->jiffies_stall,
jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/*
* OK, time to rat on our buddy...
@@ -1292,7 +1291,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
ndetected++;
}
}
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
print_cpu_stall_info_end();
@@ -1357,7 +1356,7 @@ static void print_cpu_stall(struct rcu_state *rsp)
if (ULONG_CMP_GE(jiffies, READ_ONCE(rsp->jiffies_stall)))
WRITE_ONCE(rsp->jiffies_stall,
jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/*
* Attempt to revive the RCU machinery by forcing a context switch.
@@ -1595,7 +1594,7 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp,
}
unlock_out:
if (rnp != rnp_root)
- raw_spin_unlock(&rnp_root->lock);
+ raw_spin_unlock_rcu_node(rnp_root);
out:
if (c_out != NULL)
*c_out = c;
@@ -1614,7 +1613,6 @@ static int rcu_future_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
int needmore;
struct rcu_data *rdp = this_cpu_ptr(rsp->rda);
- rcu_nocb_gp_cleanup(rsp, rnp);
rnp->need_future_gp[c & 0x1] = 0;
needmore = rnp->need_future_gp[(c + 1) & 0x1];
trace_rcu_future_gp(rnp, rdp, c,
@@ -1635,7 +1633,7 @@ static void rcu_gp_kthread_wake(struct rcu_state *rsp)
!READ_ONCE(rsp->gp_flags) ||
!rsp->gp_kthread)
return;
- wake_up(&rsp->gp_wq);
+ swake_up(&rsp->gp_wq);
}
/*
@@ -1815,7 +1813,7 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
return;
}
needwake = __note_gp_changes(rsp, rnp, rdp);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
if (needwake)
rcu_gp_kthread_wake(rsp);
}
@@ -1840,7 +1838,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
raw_spin_lock_irq_rcu_node(rnp);
if (!READ_ONCE(rsp->gp_flags)) {
/* Spurious wakeup, tell caller to go back to sleep. */
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
return false;
}
WRITE_ONCE(rsp->gp_flags, 0); /* Clear all flags: New grace period. */
@@ -1850,7 +1848,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
* Grace period already in progress, don't start another.
* Not supposed to be able to happen.
*/
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
return false;
}
@@ -1859,7 +1857,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
/* Record GP times before starting GP, hence smp_store_release(). */
smp_store_release(&rsp->gpnum, rsp->gpnum + 1);
trace_rcu_grace_period(rsp->name, rsp->gpnum, TPS("start"));
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
/*
* Apply per-leaf buffered online and offline operations to the
@@ -1873,7 +1871,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
if (rnp->qsmaskinit == rnp->qsmaskinitnext &&
!rnp->wait_blkd_tasks) {
/* Nothing to do on this leaf rcu_node structure. */
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
continue;
}
@@ -1907,7 +1905,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
rcu_cleanup_dead_rnp(rnp);
}
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
}
/*
@@ -1938,7 +1936,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
trace_rcu_grace_period_init(rsp->name, rnp->gpnum,
rnp->level, rnp->grplo,
rnp->grphi, rnp->qsmask);
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
cond_resched_rcu_qs();
WRITE_ONCE(rsp->gp_activity, jiffies);
}
@@ -1996,7 +1994,7 @@ static void rcu_gp_fqs(struct rcu_state *rsp, bool first_time)
raw_spin_lock_irq_rcu_node(rnp);
WRITE_ONCE(rsp->gp_flags,
READ_ONCE(rsp->gp_flags) & ~RCU_GP_FLAG_FQS);
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
}
}
@@ -2010,6 +2008,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
int nocb = 0;
struct rcu_data *rdp;
struct rcu_node *rnp = rcu_get_root(rsp);
+ struct swait_queue_head *sq;
WRITE_ONCE(rsp->gp_activity, jiffies);
raw_spin_lock_irq_rcu_node(rnp);
@@ -2025,7 +2024,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
* safe for us to drop the lock in order to mark the grace
* period as completed in all of the rcu_node structures.
*/
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
/*
* Propagate new ->completed value to rcu_node structures so
@@ -2046,7 +2045,9 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
needgp = __note_gp_changes(rsp, rnp, rdp) || needgp;
/* smp_mb() provided by prior unlock-lock pair. */
nocb += rcu_future_gp_cleanup(rsp, rnp);
- raw_spin_unlock_irq(&rnp->lock);
+ sq = rcu_nocb_gp_get(rnp);
+ raw_spin_unlock_irq_rcu_node(rnp);
+ rcu_nocb_gp_cleanup(sq);
cond_resched_rcu_qs();
WRITE_ONCE(rsp->gp_activity, jiffies);
rcu_gp_slow(rsp, gp_cleanup_delay);
@@ -2068,7 +2069,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
READ_ONCE(rsp->gpnum),
TPS("newreq"));
}
- raw_spin_unlock_irq(&rnp->lock);
+ raw_spin_unlock_irq_rcu_node(rnp);
}
/*
@@ -2092,7 +2093,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("reqwait"));
rsp->gp_state = RCU_GP_WAIT_GPS;
- wait_event_interruptible(rsp->gp_wq,
+ swait_event_interruptible(rsp->gp_wq,
READ_ONCE(rsp->gp_flags) &
RCU_GP_FLAG_INIT);
rsp->gp_state = RCU_GP_DONE_GPS;
@@ -2122,7 +2123,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("fqswait"));
rsp->gp_state = RCU_GP_WAIT_FQS;
- ret = wait_event_interruptible_timeout(rsp->gp_wq,
+ ret = swait_event_interruptible_timeout(rsp->gp_wq,
rcu_gp_fqs_check_wake(rsp, &gf), j);
rsp->gp_state = RCU_GP_DOING_FQS;
/* Locking provides needed memory barriers. */
@@ -2234,19 +2235,21 @@ static bool rcu_start_gp(struct rcu_state *rsp)
}
/*
- * Report a full set of quiescent states to the specified rcu_state
- * data structure. This involves cleaning up after the prior grace
- * period and letting rcu_start_gp() start up the next grace period
- * if one is needed. Note that the caller must hold rnp->lock, which
- * is released before return.
+ * Report a full set of quiescent states to the specified rcu_state data
+ * structure. Invoke rcu_gp_kthread_wake() to awaken the grace-period
+ * kthread if another grace period is required. Whether we wake
+ * the grace-period kthread or it awakens itself for the next round
+ * of quiescent-state forcing, that kthread will clean up after the
+ * just-completed grace period. Note that the caller must hold rnp->lock,
+ * which is released before return.
*/
static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
__releases(rcu_get_root(rsp)->lock)
{
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
- raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
- rcu_gp_kthread_wake(rsp);
+ raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags);
+ swake_up(&rsp->gp_wq); /* Memory barrier implied by swake_up() path. */
}
/*
@@ -2275,7 +2278,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
* Our bit has already been cleared, or the
* relevant grace period is already over, so done.
*/
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
WARN_ON_ONCE(oldmask); /* Any child must be all zeroed! */
@@ -2287,7 +2290,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
if (rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) {
/* Other bits still set at this level, so done. */
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
mask = rnp->grpmask;
@@ -2297,7 +2300,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
break;
}
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
rnp_c = rnp;
rnp = rnp->parent;
raw_spin_lock_irqsave_rcu_node(rnp, flags);
@@ -2329,7 +2332,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp,
if (rcu_state_p == &rcu_sched_state || rsp != rcu_state_p ||
rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return; /* Still need more quiescent states! */
}
@@ -2346,19 +2349,14 @@ static void rcu_report_unblock_qs_rnp(struct rcu_state *rsp,
/* Report up the rest of the hierarchy, tracking current ->gpnum. */
gps = rnp->gpnum;
mask = rnp->grpmask;
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
raw_spin_lock_rcu_node(rnp_p); /* irqs already disabled. */
rcu_report_qs_rnp(mask, rsp, rnp_p, gps, flags);
}
/*
* Record a quiescent state for the specified CPU to that CPU's rcu_data
- * structure. This must be either called from the specified CPU, or
- * called when the specified CPU is known to be offline (and when it is
- * also known that no other CPU is concurrently trying to help the offline
- * CPU). The lastcomp argument is used to make sure we are still in the
- * grace period of interest. We don't want to end the current grace period
- * based on quiescent states detected in an earlier grace period!
+ * structure. This must be called from the specified CPU.
*/
static void
rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
@@ -2383,14 +2381,14 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
*/
rdp->cpu_no_qs.b.norm = true; /* need qs for new gp. */
rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
mask = rdp->grpmask;
if ((rnp->qsmask & mask) == 0) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
} else {
- rdp->core_needs_qs = 0;
+ rdp->core_needs_qs = false;
/*
* This GP can't end until cpu checks in, so all of our
@@ -2599,36 +2597,15 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf)
rnp->qsmaskinit &= ~mask;
rnp->qsmask &= ~mask;
if (rnp->qsmaskinit) {
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp);
+ /* irqs remain disabled. */
return;
}
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
}
}
/*
- * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
- * function. We now remove it from the rcu_node tree's ->qsmaskinit
- * bit masks.
- */
-static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
-{
- unsigned long flags;
- unsigned long mask;
- struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
- struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
-
- if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
- return;
-
- /* Remove outgoing CPU from mask in the leaf rcu_node structure. */
- mask = rdp->grpmask;
- raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
- rnp->qsmaskinitnext &= ~mask;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
-}
-
-/*
* The CPU has been completely removed, and some other CPU is reporting
* this fact from process context. Do the remainder of the cleanup,
* including orphaning the outgoing CPU's RCU callbacks, and also
@@ -2859,7 +2836,7 @@ static void force_qs_rnp(struct rcu_state *rsp,
rcu_report_qs_rnp(mask, rsp, rnp, rnp->gpnum, flags);
} else {
/* Nothing to do here, so just drop the lock. */
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
}
@@ -2895,12 +2872,12 @@ static void force_quiescent_state(struct rcu_state *rsp)
raw_spin_unlock(&rnp_old->fqslock);
if (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
rsp->n_force_qs_lh++;
- raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
return; /* Someone beat us to it. */
}
WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
- raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
- rcu_gp_kthread_wake(rsp);
+ raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
+ swake_up(&rsp->gp_wq); /* Memory barrier implied by swake_up() path. */
}
/*
@@ -2925,7 +2902,7 @@ __rcu_process_callbacks(struct rcu_state *rsp)
if (cpu_needs_another_gp(rsp, rdp)) {
raw_spin_lock_rcu_node(rcu_get_root(rsp)); /* irqs disabled. */
needwake = rcu_start_gp(rsp);
- raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags);
if (needwake)
rcu_gp_kthread_wake(rsp);
} else {
@@ -3016,7 +2993,7 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
raw_spin_lock_rcu_node(rnp_root);
needwake = rcu_start_gp(rsp);
- raw_spin_unlock(&rnp_root->lock);
+ raw_spin_unlock_rcu_node(rnp_root);
if (needwake)
rcu_gp_kthread_wake(rsp);
} else {
@@ -3436,14 +3413,14 @@ static void sync_exp_reset_tree_hotplug(struct rcu_state *rsp)
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (rnp->expmaskinit == rnp->expmaskinitnext) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
continue; /* No new CPUs, nothing to do. */
}
/* Update this node's mask, track old value for propagation. */
oldmask = rnp->expmaskinit;
rnp->expmaskinit = rnp->expmaskinitnext;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/* If was already nonzero, nothing to propagate. */
if (oldmask)
@@ -3458,7 +3435,7 @@ static void sync_exp_reset_tree_hotplug(struct rcu_state *rsp)
if (rnp_up->expmaskinit)
done = true;
rnp_up->expmaskinit |= mask;
- raw_spin_unlock_irqrestore(&rnp_up->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp_up, flags);
if (done)
break;
mask = rnp_up->grpmask;
@@ -3481,7 +3458,7 @@ static void __maybe_unused sync_exp_reset_tree(struct rcu_state *rsp)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
WARN_ON_ONCE(rnp->expmask);
rnp->expmask = rnp->expmaskinit;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
@@ -3522,19 +3499,19 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
if (!rnp->expmask)
rcu_initiate_boost(rnp, flags);
else
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
break;
}
if (rnp->parent == NULL) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
if (wake) {
smp_mb(); /* EGP done before wake_up(). */
- wake_up(&rsp->expedited_wq);
+ swake_up(&rsp->expedited_wq);
}
break;
}
mask = rnp->grpmask;
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
+ raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled */
rnp = rnp->parent;
raw_spin_lock_rcu_node(rnp); /* irqs already disabled */
WARN_ON_ONCE(!(rnp->expmask & mask));
@@ -3569,7 +3546,7 @@ static void rcu_report_exp_cpu_mult(struct rcu_state *rsp, struct rcu_node *rnp,
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (!(rnp->expmask & mask)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
rnp->expmask &= ~mask;
@@ -3730,7 +3707,7 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
*/
if (rcu_preempt_has_tasks(rnp))
rnp->exp_tasks = rnp->blkd_tasks.next;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/* IPI the remaining CPUs for expedited quiescent state. */
mask = 1;
@@ -3747,7 +3724,7 @@ retry_ipi:
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (cpu_online(cpu) &&
(rnp->expmask & mask)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
schedule_timeout_uninterruptible(1);
if (cpu_online(cpu) &&
(rnp->expmask & mask))
@@ -3756,7 +3733,7 @@ retry_ipi:
}
if (!(rnp->expmask & mask))
mask_ofl_ipi &= ~mask;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
/* Report quiescent states for those that went offline. */
mask_ofl_test |= mask_ofl_ipi;
@@ -3780,7 +3757,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
jiffies_start = jiffies;
for (;;) {
- ret = wait_event_interruptible_timeout(
+ ret = swait_event_timeout(
rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp_root),
jiffies_stall);
@@ -3788,7 +3765,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
return;
if (ret < 0) {
/* Hit a signal, disable CPU stall warnings. */
- wait_event(rsp->expedited_wq,
+ swait_event(rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp_root));
return;
}
@@ -4163,7 +4140,7 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
return;
raw_spin_lock_rcu_node(rnp); /* Interrupts already disabled. */
rnp->qsmaskinit |= mask;
- raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* Interrupts remain disabled. */
}
}
@@ -4187,7 +4164,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->rsp = rsp;
mutex_init(&rdp->exp_funnel_mutex);
rcu_boot_init_nocb_percpu_data(rdp);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
/*
@@ -4215,7 +4192,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
rcu_sysidle_init_percpu_data(rdp->dynticks);
atomic_set(&rdp->dynticks->dynticks,
(atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1);
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
/*
* Add CPU to leaf rcu_node pending-online bitmask. Any needed
@@ -4236,7 +4213,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu);
rdp->core_needs_qs = false;
trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
static void rcu_prepare_cpu(int cpu)
@@ -4247,6 +4224,46 @@ static void rcu_prepare_cpu(int cpu)
rcu_init_percpu_data(cpu, rsp);
}
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
+ * function. We now remove it from the rcu_node tree's ->qsmaskinit
+ * bit masks.
+ * The CPU is exiting the idle loop into the arch_cpu_idle_dead()
+ * function. We now remove it from the rcu_node tree's ->qsmaskinit
+ * bit masks.
+ */
+static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
+{
+ unsigned long flags;
+ unsigned long mask;
+ struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
+ struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
+
+ if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
+ return;
+
+ /* Remove outgoing CPU from mask in the leaf rcu_node structure. */
+ mask = rdp->grpmask;
+ raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
+ rnp->qsmaskinitnext &= ~mask;
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+}
+
+void rcu_report_dead(unsigned int cpu)
+{
+ struct rcu_state *rsp;
+
+ /* QS for any half-done expedited RCU-sched GP. */
+ preempt_disable();
+ rcu_report_exp_rdp(&rcu_sched_state,
+ this_cpu_ptr(rcu_sched_state.rda), true);
+ preempt_enable();
+ for_each_rcu_flavor(rsp)
+ rcu_cleanup_dying_idle_cpu(cpu, rsp);
+}
+#endif
+
/*
* Handle CPU online/offline notification events.
*/
@@ -4278,17 +4295,6 @@ int rcu_cpu_notify(struct notifier_block *self,
for_each_rcu_flavor(rsp)
rcu_cleanup_dying_cpu(rsp);
break;
- case CPU_DYING_IDLE:
- /* QS for any half-done expedited RCU-sched GP. */
- preempt_disable();
- rcu_report_exp_rdp(&rcu_sched_state,
- this_cpu_ptr(rcu_sched_state.rda), true);
- preempt_enable();
-
- for_each_rcu_flavor(rsp) {
- rcu_cleanup_dying_idle_cpu(cpu, rsp);
- }
- break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
case CPU_UP_CANCELED:
@@ -4358,7 +4364,7 @@ static int __init rcu_spawn_gp_kthread(void)
sp.sched_priority = kthread_prio;
sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
}
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
wake_up_process(t);
}
rcu_spawn_nocb_kthreads();
@@ -4449,8 +4455,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
cpustride *= levelspread[i];
rnp = rsp->level[i];
for (j = 0; j < levelcnt[i]; j++, rnp++) {
- raw_spin_lock_init(&rnp->lock);
- lockdep_set_class_and_name(&rnp->lock,
+ raw_spin_lock_init(&ACCESS_PRIVATE(rnp, lock));
+ lockdep_set_class_and_name(&ACCESS_PRIVATE(rnp, lock),
&rcu_node_class[i], buf[i]);
raw_spin_lock_init(&rnp->fqslock);
lockdep_set_class_and_name(&rnp->fqslock,
@@ -4482,8 +4488,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
}
}
- init_waitqueue_head(&rsp->gp_wq);
- init_waitqueue_head(&rsp->expedited_wq);
+ init_swait_queue_head(&rsp->gp_wq);
+ init_swait_queue_head(&rsp->expedited_wq);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
while (i > rnp->grphi)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 83360b4f4352..df668c0f9e64 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -27,6 +27,7 @@
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
+#include <linux/swait.h>
#include <linux/stop_machine.h>
/*
@@ -149,8 +150,9 @@ struct rcu_dynticks {
* Definition for node within the RCU grace-period-detection hierarchy.
*/
struct rcu_node {
- raw_spinlock_t lock; /* Root rcu_node's lock protects some */
- /* rcu_state fields as well as following. */
+ raw_spinlock_t __private lock; /* Root rcu_node's lock protects */
+ /* some rcu_state fields as well as */
+ /* following. */
unsigned long gpnum; /* Current grace period for this node. */
/* This will either be equal to or one */
/* behind the root rcu_node's gpnum. */
@@ -243,7 +245,7 @@ struct rcu_node {
/* Refused to boost: not sure why, though. */
/* This can happen due to race conditions. */
#ifdef CONFIG_RCU_NOCB_CPU
- wait_queue_head_t nocb_gp_wq[2];
+ struct swait_queue_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
int need_future_gp[2];
@@ -399,7 +401,7 @@ struct rcu_data {
atomic_long_t nocb_q_count_lazy; /* invocation (all stages). */
struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */
struct rcu_head **nocb_follower_tail;
- wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */
+ struct swait_queue_head nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
int nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */
@@ -478,7 +480,7 @@ struct rcu_state {
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
struct task_struct *gp_kthread; /* Task for grace periods. */
- wait_queue_head_t gp_wq; /* Where GP task waits. */
+ struct swait_queue_head gp_wq; /* Where GP task waits. */
short gp_flags; /* Commands for GP task. */
short gp_state; /* GP kthread sleep state. */
@@ -506,7 +508,7 @@ struct rcu_state {
unsigned long expedited_sequence; /* Take a ticket. */
atomic_long_t expedited_normal; /* # fallbacks to normal. */
atomic_t expedited_need_qs; /* # CPUs left to check in. */
- wait_queue_head_t expedited_wq; /* Wait for check-ins. */
+ struct swait_queue_head expedited_wq; /* Wait for check-ins. */
int ncpus_snap; /* # CPUs seen last time. */
unsigned long jiffies_force_qs; /* Time at which to invoke */
@@ -621,7 +623,8 @@ static void zero_cpu_stall_ticks(struct rcu_data *rdp);
static void increment_cpu_stall_ticks(void);
static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu);
static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq);
-static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp);
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);
static void rcu_init_one_nocb(struct rcu_node *rnp);
static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
bool lazy, unsigned long flags);
@@ -680,7 +683,7 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
#endif /* #else #ifdef CONFIG_PPC */
/*
- * Wrappers for the rcu_node::lock acquire.
+ * Wrappers for the rcu_node::lock acquire and release.
*
* Because the rcu_nodes form a tree, the tree traversal locking will observe
* different lock values, this in turn means that an UNLOCK of one level
@@ -689,29 +692,48 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
*
* In order to restore full ordering between tree levels, augment the regular
* lock acquire functions with smp_mb__after_unlock_lock().
+ *
+ * As ->lock of struct rcu_node is a __private field, therefore one should use
+ * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock.
*/
static inline void raw_spin_lock_rcu_node(struct rcu_node *rnp)
{
- raw_spin_lock(&rnp->lock);
+ raw_spin_lock(&ACCESS_PRIVATE(rnp, lock));
smp_mb__after_unlock_lock();
}
+static inline void raw_spin_unlock_rcu_node(struct rcu_node *rnp)
+{
+ raw_spin_unlock(&ACCESS_PRIVATE(rnp, lock));
+}
+
static inline void raw_spin_lock_irq_rcu_node(struct rcu_node *rnp)
{
- raw_spin_lock_irq(&rnp->lock);
+ raw_spin_lock_irq(&ACCESS_PRIVATE(rnp, lock));
smp_mb__after_unlock_lock();
}
-#define raw_spin_lock_irqsave_rcu_node(rnp, flags) \
-do { \
- typecheck(unsigned long, flags); \
- raw_spin_lock_irqsave(&(rnp)->lock, flags); \
- smp_mb__after_unlock_lock(); \
+static inline void raw_spin_unlock_irq_rcu_node(struct rcu_node *rnp)
+{
+ raw_spin_unlock_irq(&ACCESS_PRIVATE(rnp, lock));
+}
+
+#define raw_spin_lock_irqsave_rcu_node(rnp, flags) \
+do { \
+ typecheck(unsigned long, flags); \
+ raw_spin_lock_irqsave(&ACCESS_PRIVATE(rnp, lock), flags); \
+ smp_mb__after_unlock_lock(); \
+} while (0)
+
+#define raw_spin_unlock_irqrestore_rcu_node(rnp, flags) \
+do { \
+ typecheck(unsigned long, flags); \
+ raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(rnp, lock), flags); \
} while (0)
static inline bool raw_spin_trylock_rcu_node(struct rcu_node *rnp)
{
- bool locked = raw_spin_trylock(&rnp->lock);
+ bool locked = raw_spin_trylock(&ACCESS_PRIVATE(rnp, lock));
if (locked)
smp_mb__after_unlock_lock();
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 9467a8b7e756..efdf7b61ce12 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -235,7 +235,7 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
rnp->gp_tasks = &t->rcu_node_entry;
if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD))
rnp->exp_tasks = &t->rcu_node_entry;
- raw_spin_unlock(&rnp->lock); /* rrupts remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* interrupts remain disabled. */
/*
* Report the quiescent state for the expedited GP. This expedited
@@ -489,7 +489,7 @@ void rcu_read_unlock_special(struct task_struct *t)
!!rnp->gp_tasks);
rcu_report_unblock_qs_rnp(rcu_state_p, rnp, flags);
} else {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
/* Unboost if we were boosted. */
@@ -518,14 +518,14 @@ static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (!rcu_preempt_blocked_readers_cgp(rnp)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
t = list_entry(rnp->gp_tasks->prev,
struct task_struct, rcu_node_entry);
list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry)
sched_show_task(t);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
/*
@@ -807,7 +807,6 @@ void exit_rcu(void)
#else /* #ifdef CONFIG_PREEMPT_RCU */
static struct rcu_state *const rcu_state_p = &rcu_sched_state;
-static struct rcu_data __percpu *const rcu_data_p = &rcu_sched_data;
/*
* Tell them what RCU they are running.
@@ -991,7 +990,7 @@ static int rcu_boost(struct rcu_node *rnp)
* might exit their RCU read-side critical sections on their own.
*/
if (rnp->exp_tasks == NULL && rnp->boost_tasks == NULL) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return 0;
}
@@ -1028,7 +1027,7 @@ static int rcu_boost(struct rcu_node *rnp)
*/
t = container_of(tb, struct task_struct, rcu_node_entry);
rt_mutex_init_proxy_locked(&rnp->boost_mtx, t);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/* Lock only for side effect: boosts task t's priority. */
rt_mutex_lock(&rnp->boost_mtx);
rt_mutex_unlock(&rnp->boost_mtx); /* Then keep lockdep happy. */
@@ -1088,7 +1087,7 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) {
rnp->n_balk_exp_gp_tasks++;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
if (rnp->exp_tasks != NULL ||
@@ -1098,13 +1097,13 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
ULONG_CMP_GE(jiffies, rnp->boost_time))) {
if (rnp->exp_tasks == NULL)
rnp->boost_tasks = rnp->gp_tasks;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
t = rnp->boost_kthread_task;
if (t)
rcu_wake_cond(t, rnp->boost_kthread_status);
} else {
rcu_initiate_boost_trace(rnp);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
@@ -1172,7 +1171,7 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
return PTR_ERR(t);
raw_spin_lock_irqsave_rcu_node(rnp, flags);
rnp->boost_kthread_task = t;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
sp.sched_priority = kthread_prio;
sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
@@ -1308,7 +1307,7 @@ static void rcu_prepare_kthreads(int cpu)
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
__releases(rnp->lock)
{
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
static void invoke_rcu_callbacks_kthread(void)
@@ -1559,7 +1558,7 @@ static void rcu_prepare_for_idle(void)
rnp = rdp->mynode;
raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */
needwake = rcu_accelerate_cbs(rsp, rnp, rdp);
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
if (needwake)
rcu_gp_kthread_wake(rsp);
}
@@ -1811,9 +1810,9 @@ early_param("rcu_nocb_poll", parse_rcu_nocb_poll);
* Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended
* grace period.
*/
-static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq)
{
- wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
+ swake_up_all(sq);
}
/*
@@ -1829,10 +1828,15 @@ static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq)
rnp->need_future_gp[(rnp->completed + 1) & 0x1] += nrq;
}
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp)
+{
+ return &rnp->nocb_gp_wq[rnp->completed & 0x1];
+}
+
static void rcu_init_one_nocb(struct rcu_node *rnp)
{
- init_waitqueue_head(&rnp->nocb_gp_wq[0]);
- init_waitqueue_head(&rnp->nocb_gp_wq[1]);
+ init_swait_queue_head(&rnp->nocb_gp_wq[0]);
+ init_swait_queue_head(&rnp->nocb_gp_wq[1]);
}
#ifndef CONFIG_RCU_NOCB_CPU_ALL
@@ -1857,7 +1861,7 @@ static void wake_nocb_leader(struct rcu_data *rdp, bool force)
if (READ_ONCE(rdp_leader->nocb_leader_sleep) || force) {
/* Prior smp_mb__after_atomic() orders against prior enqueue. */
WRITE_ONCE(rdp_leader->nocb_leader_sleep, false);
- wake_up(&rdp_leader->nocb_wq);
+ swake_up(&rdp_leader->nocb_wq);
}
}
@@ -2059,7 +2063,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
needwake = rcu_start_future_gp(rnp, rdp, &c);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
if (needwake)
rcu_gp_kthread_wake(rdp->rsp);
@@ -2069,7 +2073,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
*/
trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- wait_event_interruptible(
+ swait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(READ_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2097,7 +2101,7 @@ wait_again:
/* Wait for callbacks to appear. */
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep");
- wait_event_interruptible(my_rdp->nocb_wq,
+ swait_event_interruptible(my_rdp->nocb_wq,
!READ_ONCE(my_rdp->nocb_leader_sleep));
/* Memory barrier handled by smp_mb() calls below and repoll. */
} else if (firsttime) {
@@ -2172,7 +2176,7 @@ wait_again:
* List was empty, wake up the follower.
* Memory barriers supplied by atomic_long_add().
*/
- wake_up(&rdp->nocb_wq);
+ swake_up(&rdp->nocb_wq);
}
}
@@ -2193,7 +2197,7 @@ static void nocb_follower_wait(struct rcu_data *rdp)
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
"FollowerSleep");
- wait_event_interruptible(rdp->nocb_wq,
+ swait_event_interruptible(rdp->nocb_wq,
READ_ONCE(rdp->nocb_follower_head));
} else if (firsttime) {
/* Don't drown trace log with "Poll"! */
@@ -2352,7 +2356,7 @@ void __init rcu_init_nohz(void)
static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
{
rdp->nocb_tail = &rdp->nocb_head;
- init_waitqueue_head(&rdp->nocb_wq);
+ init_swait_queue_head(&rdp->nocb_wq);
rdp->nocb_follower_tail = &rdp->nocb_follower_head;
}
@@ -2502,7 +2506,7 @@ static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)
return false;
}
-static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq)
{
}
@@ -2510,6 +2514,11 @@ static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq)
{
}
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp)
+{
+ return NULL;
+}
+
static void rcu_init_one_nocb(struct rcu_node *rnp)
{
}
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 76b94e19430b..ca828b41c938 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -128,6 +128,7 @@ bool rcu_gp_is_normal(void)
{
return READ_ONCE(rcu_normal);
}
+EXPORT_SYMBOL_GPL(rcu_gp_is_normal);
static atomic_t rcu_expedited_nesting =
ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0);
diff --git a/kernel/resource.c b/kernel/resource.c
index 09c0597840b0..2e78ead30934 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -233,9 +233,9 @@ static struct resource * __request_resource(struct resource *root, struct resour
}
}
-static int __release_resource(struct resource *old)
+static int __release_resource(struct resource *old, bool release_child)
{
- struct resource *tmp, **p;
+ struct resource *tmp, **p, *chd;
p = &old->parent->child;
for (;;) {
@@ -243,7 +243,17 @@ static int __release_resource(struct resource *old)
if (!tmp)
break;
if (tmp == old) {
- *p = tmp->sibling;
+ if (release_child || !(tmp->child)) {
+ *p = tmp->sibling;
+ } else {
+ for (chd = tmp->child;; chd = chd->sibling) {
+ chd->parent = tmp->parent;
+ if (!(chd->sibling))
+ break;
+ }
+ *p = tmp->child;
+ chd->sibling = tmp->sibling;
+ }
old->parent = NULL;
return 0;
}
@@ -325,7 +335,7 @@ int release_resource(struct resource *old)
int retval;
write_lock(&resource_lock);
- retval = __release_resource(old);
+ retval = __release_resource(old, true);
write_unlock(&resource_lock);
return retval;
}
@@ -333,13 +343,13 @@ int release_resource(struct resource *old)
EXPORT_SYMBOL(release_resource);
/*
- * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
- * the caller must specify res->start, res->end, res->flags and "name".
- * If found, returns 0, res is overwritten, if not found, returns -1.
- * This walks through whole tree and not just first level children
- * until and unless first_level_children_only is true.
+ * Finds the lowest iomem resource existing within [res->start.res->end).
+ * The caller must specify res->start, res->end, res->flags, and optionally
+ * desc. If found, returns 0, res is overwritten, if not found, returns -1.
+ * This function walks the whole tree and not just first level children until
+ * and unless first_level_children_only is true.
*/
-static int find_next_iomem_res(struct resource *res, char *name,
+static int find_next_iomem_res(struct resource *res, unsigned long desc,
bool first_level_children_only)
{
resource_size_t start, end;
@@ -358,9 +368,9 @@ static int find_next_iomem_res(struct resource *res, char *name,
read_lock(&resource_lock);
for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
- if (p->flags != res->flags)
+ if ((p->flags & res->flags) != res->flags)
continue;
- if (name && strcmp(p->name, name))
+ if ((desc != IORES_DESC_NONE) && (desc != p->desc))
continue;
if (p->start > end) {
p = NULL;
@@ -385,15 +395,18 @@ static int find_next_iomem_res(struct resource *res, char *name,
* Walks through iomem resources and calls func() with matching resource
* ranges. This walks through whole tree and not just first level children.
* All the memory ranges which overlap start,end and also match flags and
- * name are valid candidates.
+ * desc are valid candidates.
*
- * @name: name of resource
- * @flags: resource flags
+ * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
+ * @flags: I/O resource flags
* @start: start addr
* @end: end addr
+ *
+ * NOTE: For a new descriptor search, define a new IORES_DESC in
+ * <linux/ioport.h> and set it in 'desc' of a target resource entry.
*/
-int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
- void *arg, int (*func)(u64, u64, void *))
+int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
+ u64 end, void *arg, int (*func)(u64, u64, void *))
{
struct resource res;
u64 orig_end;
@@ -403,23 +416,27 @@ int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
res.end = end;
res.flags = flags;
orig_end = res.end;
+
while ((res.start < res.end) &&
- (!find_next_iomem_res(&res, name, false))) {
+ (!find_next_iomem_res(&res, desc, false))) {
+
ret = (*func)(res.start, res.end, arg);
if (ret)
break;
+
res.start = res.end + 1;
res.end = orig_end;
}
+
return ret;
}
/*
- * This function calls callback against all memory range of "System RAM"
- * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
- * Now, this function is only for "System RAM". This function deals with
- * full ranges and not pfn. If resources are not pfn aligned, dealing
- * with pfn can truncate ranges.
+ * This function calls the @func callback against all memory ranges of type
+ * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
+ * Now, this function is only for System RAM, it deals with full ranges and
+ * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
+ * ranges.
*/
int walk_system_ram_res(u64 start, u64 end, void *arg,
int (*func)(u64, u64, void *))
@@ -430,10 +447,10 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
res.start = start;
res.end = end;
- res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
orig_end = res.end;
while ((res.start < res.end) &&
- (!find_next_iomem_res(&res, "System RAM", true))) {
+ (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) {
ret = (*func)(res.start, res.end, arg);
if (ret)
break;
@@ -446,9 +463,9 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
/*
- * This function calls callback against all memory range of "System RAM"
- * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
- * Now, this function is only for "System RAM".
+ * This function calls the @func callback against all memory ranges of type
+ * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
+ * It is to be used only for System RAM.
*/
int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
@@ -460,10 +477,10 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
res.start = (u64) start_pfn << PAGE_SHIFT;
res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
- res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
orig_end = res.end;
while ((res.start < res.end) &&
- (find_next_iomem_res(&res, "System RAM", true) >= 0)) {
+ (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
end_pfn = (res.end + 1) >> PAGE_SHIFT;
if (end_pfn > pfn)
@@ -484,7 +501,7 @@ static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
}
/*
* This generic page_is_ram() returns true if specified address is
- * registered as "System RAM" in iomem_resource list.
+ * registered as System RAM in iomem_resource list.
*/
int __weak page_is_ram(unsigned long pfn)
{
@@ -496,30 +513,34 @@ EXPORT_SYMBOL_GPL(page_is_ram);
* region_intersects() - determine intersection of region with known resources
* @start: region start address
* @size: size of region
- * @name: name of resource (in iomem_resource)
+ * @flags: flags of resource (in iomem_resource)
+ * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
*
* Check if the specified region partially overlaps or fully eclipses a
- * resource identified by @name. Return REGION_DISJOINT if the region
- * does not overlap @name, return REGION_MIXED if the region overlaps
- * @type and another resource, and return REGION_INTERSECTS if the
- * region overlaps @type and no other defined resource. Note, that
- * REGION_INTERSECTS is also returned in the case when the specified
- * region overlaps RAM and undefined memory holes.
+ * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
+ * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
+ * return REGION_MIXED if the region overlaps @flags/@desc and another
+ * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
+ * and no other defined resource. Note that REGION_INTERSECTS is also
+ * returned in the case when the specified region overlaps RAM and undefined
+ * memory holes.
*
* region_intersect() is used by memory remapping functions to ensure
* the user is not remapping RAM and is a vast speed up over walking
* through the resource table page by page.
*/
-int region_intersects(resource_size_t start, size_t size, const char *name)
+int region_intersects(resource_size_t start, size_t size, unsigned long flags,
+ unsigned long desc)
{
- unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
resource_size_t end = start + size - 1;
int type = 0; int other = 0;
struct resource *p;
read_lock(&resource_lock);
for (p = iomem_resource.child; p ; p = p->sibling) {
- bool is_type = strcmp(p->name, name) == 0 && p->flags == flags;
+ bool is_type = (((p->flags & flags) == flags) &&
+ ((desc == IORES_DESC_NONE) ||
+ (desc == p->desc)));
if (start >= p->start && start <= p->end)
is_type ? type++ : other++;
@@ -538,6 +559,7 @@ int region_intersects(resource_size_t start, size_t size, const char *name)
return REGION_DISJOINT;
}
+EXPORT_SYMBOL_GPL(region_intersects);
void __weak arch_remove_reservations(struct resource *avail)
{
@@ -667,7 +689,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
old->start = new.start;
old->end = new.end;
} else {
- __release_resource(old);
+ __release_resource(old, true);
*old = new;
conflict = __request_resource(root, old);
BUG_ON(conflict);
@@ -813,6 +835,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
* entirely fit within the range of the new resource, then the new
* resource is inserted and the conflicting resources become children of
* the new resource.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
*/
struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
{
@@ -830,6 +855,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour
* @new: new resource to insert
*
* Returns 0 on success, -EBUSY if the resource can't be inserted.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
*/
int insert_resource(struct resource *parent, struct resource *new)
{
@@ -838,6 +866,7 @@ int insert_resource(struct resource *parent, struct resource *new)
conflict = insert_resource_conflict(parent, new);
return conflict ? -EBUSY : 0;
}
+EXPORT_SYMBOL_GPL(insert_resource);
/**
* insert_resource_expand_to_fit - Insert a resource into the resource tree
@@ -873,6 +902,32 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
write_unlock(&resource_lock);
}
+/**
+ * remove_resource - Remove a resource in the resource tree
+ * @old: resource to remove
+ *
+ * Returns 0 on success, -EINVAL if the resource is not valid.
+ *
+ * This function removes a resource previously inserted by insert_resource()
+ * or insert_resource_conflict(), and moves the children (if any) up to
+ * where they were before. insert_resource() and insert_resource_conflict()
+ * insert a new resource, and move any conflicting resources down to the
+ * children of the new resource.
+ *
+ * insert_resource(), insert_resource_conflict() and remove_resource() are
+ * intended for producers of resources, such as FW modules and bus drivers.
+ */
+int remove_resource(struct resource *old)
+{
+ int retval;
+
+ write_lock(&resource_lock);
+ retval = __release_resource(old, false);
+ write_unlock(&resource_lock);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(remove_resource);
+
static int __adjust_resource(struct resource *res, resource_size_t start,
resource_size_t size)
{
@@ -948,6 +1003,7 @@ static void __init __reserve_region_with_split(struct resource *root,
res->start = start;
res->end = end;
res->flags = IORESOURCE_BUSY;
+ res->desc = IORES_DESC_NONE;
while (1) {
@@ -982,6 +1038,7 @@ static void __init __reserve_region_with_split(struct resource *root,
next_res->start = conflict->end + 1;
next_res->end = end;
next_res->flags = IORESOURCE_BUSY;
+ next_res->desc = IORES_DESC_NONE;
}
} else {
res->start = conflict->end + 1;
@@ -1071,21 +1128,24 @@ struct resource * __request_region(struct resource *parent,
res->name = name;
res->start = start;
res->end = start + n - 1;
- res->flags = resource_type(parent);
- res->flags |= IORESOURCE_BUSY | flags;
write_lock(&resource_lock);
for (;;) {
struct resource *conflict;
+ res->flags = resource_type(parent) | resource_ext_type(parent);
+ res->flags |= IORESOURCE_BUSY | flags;
+ res->desc = parent->desc;
+
conflict = __request_resource(parent, res);
if (!conflict)
break;
if (conflict != parent) {
- parent = conflict;
- if (!(conflict->flags & IORESOURCE_BUSY))
+ if (!(conflict->flags & IORESOURCE_BUSY)) {
+ parent = conflict;
continue;
+ }
}
if (conflict->flags & flags & IORESOURCE_MUXED) {
add_wait_queue(&muxed_resource_wait, &wait);
@@ -1237,6 +1297,7 @@ int release_mem_region_adjustable(struct resource *parent,
new_res->start = end + 1;
new_res->end = res->end;
new_res->flags = res->flags;
+ new_res->desc = res->desc;
new_res->parent = res->parent;
new_res->sibling = res->sibling;
new_res->child = NULL;
@@ -1412,6 +1473,7 @@ static int __init reserve_setup(char *str)
res->start = io_start;
res->end = io_start + io_num - 1;
res->flags = IORESOURCE_BUSY;
+ res->desc = IORES_DESC_NONE;
res->child = NULL;
if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
reserved = x+1;
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 67687973ce80..302d6ebd64f7 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -13,9 +13,10 @@ endif
obj-y += core.o loadavg.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
-obj-y += wait.o completion.o idle.o
+obj-y += wait.o swait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
+obj-$(CONFIG_CPU_FREQ) += cpufreq.o
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index bc54e84675da..fedb967a9841 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -61,6 +61,7 @@
#include <linux/static_key.h>
#include <linux/workqueue.h>
#include <linux/compiler.h>
+#include <linux/tick.h>
/*
* Scheduler clock - returns current time in nanosec units.
@@ -89,6 +90,8 @@ static void __set_sched_clock_stable(void)
{
if (!sched_clock_stable())
static_key_slow_inc(&__sched_clock_stable);
+
+ tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE);
}
void set_sched_clock_stable(void)
@@ -108,6 +111,8 @@ static void __clear_sched_clock_stable(struct work_struct *work)
/* XXX worry about clock continuity */
if (sched_clock_stable())
static_key_slow_dec(&__sched_clock_stable);
+
+ tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE);
}
static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9503d590e5ef..ea8f49ae0062 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -26,6 +26,7 @@
* Thomas Gleixner, Mike Kravetz
*/
+#include <linux/kasan.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/nmi.h>
@@ -66,12 +67,10 @@
#include <linux/pagemap.h>
#include <linux/hrtimer.h>
#include <linux/tick.h>
-#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
#include <linux/slab.h>
#include <linux/init_task.h>
-#include <linux/binfmts.h>
#include <linux/context_tracking.h>
#include <linux/compiler.h>
@@ -124,138 +123,6 @@ const_debug unsigned int sysctl_sched_features =
#undef SCHED_FEAT
-#ifdef CONFIG_SCHED_DEBUG
-#define SCHED_FEAT(name, enabled) \
- #name ,
-
-static const char * const sched_feat_names[] = {
-#include "features.h"
-};
-
-#undef SCHED_FEAT
-
-static int sched_feat_show(struct seq_file *m, void *v)
-{
- int i;
-
- for (i = 0; i < __SCHED_FEAT_NR; i++) {
- if (!(sysctl_sched_features & (1UL << i)))
- seq_puts(m, "NO_");
- seq_printf(m, "%s ", sched_feat_names[i]);
- }
- seq_puts(m, "\n");
-
- return 0;
-}
-
-#ifdef HAVE_JUMP_LABEL
-
-#define jump_label_key__true STATIC_KEY_INIT_TRUE
-#define jump_label_key__false STATIC_KEY_INIT_FALSE
-
-#define SCHED_FEAT(name, enabled) \
- jump_label_key__##enabled ,
-
-struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
-#include "features.h"
-};
-
-#undef SCHED_FEAT
-
-static void sched_feat_disable(int i)
-{
- static_key_disable(&sched_feat_keys[i]);
-}
-
-static void sched_feat_enable(int i)
-{
- static_key_enable(&sched_feat_keys[i]);
-}
-#else
-static void sched_feat_disable(int i) { };
-static void sched_feat_enable(int i) { };
-#endif /* HAVE_JUMP_LABEL */
-
-static int sched_feat_set(char *cmp)
-{
- int i;
- int neg = 0;
-
- if (strncmp(cmp, "NO_", 3) == 0) {
- neg = 1;
- cmp += 3;
- }
-
- for (i = 0; i < __SCHED_FEAT_NR; i++) {
- if (strcmp(cmp, sched_feat_names[i]) == 0) {
- if (neg) {
- sysctl_sched_features &= ~(1UL << i);
- sched_feat_disable(i);
- } else {
- sysctl_sched_features |= (1UL << i);
- sched_feat_enable(i);
- }
- break;
- }
- }
-
- return i;
-}
-
-static ssize_t
-sched_feat_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[64];
- char *cmp;
- int i;
- struct inode *inode;
-
- if (cnt > 63)
- cnt = 63;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
- cmp = strstrip(buf);
-
- /* Ensure the static_key remains in a consistent state */
- inode = file_inode(filp);
- inode_lock(inode);
- i = sched_feat_set(cmp);
- inode_unlock(inode);
- if (i == __SCHED_FEAT_NR)
- return -EINVAL;
-
- *ppos += cnt;
-
- return cnt;
-}
-
-static int sched_feat_open(struct inode *inode, struct file *filp)
-{
- return single_open(filp, sched_feat_show, NULL);
-}
-
-static const struct file_operations sched_feat_fops = {
- .open = sched_feat_open,
- .write = sched_feat_write,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
-static __init int sched_init_debug(void)
-{
- debugfs_create_file("sched_features", 0644, NULL, NULL,
- &sched_feat_fops);
-
- return 0;
-}
-late_initcall(sched_init_debug);
-#endif /* CONFIG_SCHED_DEBUG */
-
/*
* Number of tasks to iterate in a single balance run.
* Limited because this is done with IRQs disabled.
@@ -453,20 +320,6 @@ static inline void init_hrtick(void)
}
#endif /* CONFIG_SCHED_HRTICK */
-/*
- * cmpxchg based fetch_or, macro so it works for different integer types
- */
-#define fetch_or(ptr, val) \
-({ typeof(*(ptr)) __old, __val = *(ptr); \
- for (;;) { \
- __old = cmpxchg((ptr), __val, __val | (val)); \
- if (__old == __val) \
- break; \
- __val = __old; \
- } \
- __old; \
-})
-
#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
/*
* Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
@@ -715,31 +568,36 @@ static inline bool got_nohz_idle_kick(void)
#endif /* CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_NO_HZ_FULL
-bool sched_can_stop_tick(void)
+bool sched_can_stop_tick(struct rq *rq)
{
+ int fifo_nr_running;
+
+ /* Deadline tasks, even if single, need the tick */
+ if (rq->dl.dl_nr_running)
+ return false;
+
/*
- * FIFO realtime policy runs the highest priority task. Other runnable
- * tasks are of a lower priority. The scheduler tick does nothing.
+ * FIFO realtime policy runs the highest priority task (after DEADLINE).
+ * Other runnable tasks are of a lower priority. The scheduler tick
+ * isn't needed.
*/
- if (current->policy == SCHED_FIFO)
+ fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+ if (fifo_nr_running)
return true;
/*
* Round-robin realtime tasks time slice with other tasks at the same
- * realtime priority. Is this task the only one at this priority?
+ * realtime priority.
*/
- if (current->policy == SCHED_RR) {
- struct sched_rt_entity *rt_se = &current->rt;
-
- return list_is_singular(&rt_se->run_list);
+ if (rq->rt.rr_nr_running) {
+ if (rq->rt.rr_nr_running == 1)
+ return true;
+ else
+ return false;
}
- /*
- * More than one running task need preemption.
- * nr_running update is assumed to be visible
- * after IPI is sent from wakers.
- */
- if (this_rq()->nr_running > 1)
+ /* Normal multitasking need periodic preemption checks */
+ if (rq->cfs.nr_running > 1)
return false;
return true;
@@ -2093,7 +1951,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
ttwu_queue(p, cpu);
stat:
- ttwu_stat(p, cpu, wake_flags);
+ if (schedstat_enabled())
+ ttwu_stat(p, cpu, wake_flags);
out:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
@@ -2141,7 +2000,8 @@ static void try_to_wake_up_local(struct task_struct *p)
ttwu_activate(rq, p, ENQUEUE_WAKEUP);
ttwu_do_wakeup(rq, p, 0);
- ttwu_stat(p, smp_processor_id(), 0);
+ if (schedstat_enabled())
+ ttwu_stat(p, smp_processor_id(), 0);
out:
raw_spin_unlock(&p->pi_lock);
}
@@ -2183,7 +2043,6 @@ void __dl_clear_params(struct task_struct *p)
dl_se->dl_bw = 0;
dl_se->dl_throttled = 0;
- dl_se->dl_new = 1;
dl_se->dl_yielded = 0;
}
@@ -2210,6 +2069,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
#endif
#ifdef CONFIG_SCHEDSTATS
+ /* Even if schedstat is disabled, there should not be garbage */
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
@@ -2218,6 +2078,10 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
__dl_clear_params(p);
INIT_LIST_HEAD(&p->rt.run_list);
+ p->rt.timeout = 0;
+ p->rt.time_slice = sched_rr_timeslice;
+ p->rt.on_rq = 0;
+ p->rt.on_list = 0;
#ifdef CONFIG_PREEMPT_NOTIFIERS
INIT_HLIST_HEAD(&p->preempt_notifiers);
@@ -2281,6 +2145,69 @@ int sysctl_numa_balancing(struct ctl_table *table, int write,
#endif
#endif
+DEFINE_STATIC_KEY_FALSE(sched_schedstats);
+
+#ifdef CONFIG_SCHEDSTATS
+static void set_schedstats(bool enabled)
+{
+ if (enabled)
+ static_branch_enable(&sched_schedstats);
+ else
+ static_branch_disable(&sched_schedstats);
+}
+
+void force_schedstat_enabled(void)
+{
+ if (!schedstat_enabled()) {
+ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n");
+ static_branch_enable(&sched_schedstats);
+ }
+}
+
+static int __init setup_schedstats(char *str)
+{
+ int ret = 0;
+ if (!str)
+ goto out;
+
+ if (!strcmp(str, "enable")) {
+ set_schedstats(true);
+ ret = 1;
+ } else if (!strcmp(str, "disable")) {
+ set_schedstats(false);
+ ret = 1;
+ }
+out:
+ if (!ret)
+ pr_warn("Unable to parse schedstats=\n");
+
+ return ret;
+}
+__setup("schedstats=", setup_schedstats);
+
+#ifdef CONFIG_PROC_SYSCTL
+int sysctl_schedstats(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table t;
+ int err;
+ int state = static_branch_likely(&sched_schedstats);
+
+ if (write && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ t = *table;
+ t.data = &state;
+ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
+ if (err < 0)
+ return err;
+ if (write)
+ set_schedstats(state);
+ return err;
+}
+#endif
+#endif
+
/*
* fork()/clone()-time setup:
*/
@@ -3010,16 +2937,6 @@ u64 scheduler_tick_max_deferment(void)
}
#endif
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
- if (in_lock_functions(addr)) {
- addr = CALLER_ADDR2;
- if (in_lock_functions(addr))
- addr = CALLER_ADDR3;
- }
- return addr;
-}
-
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
@@ -3041,7 +2958,7 @@ void preempt_count_add(int val)
PREEMPT_MASK - 10);
#endif
if (preempt_count() == val) {
- unsigned long ip = get_parent_ip(CALLER_ADDR1);
+ unsigned long ip = get_lock_parent_ip();
#ifdef CONFIG_DEBUG_PREEMPT
current->preempt_disable_ip = ip;
#endif
@@ -3068,7 +2985,7 @@ void preempt_count_sub(int val)
#endif
if (preempt_count() == val)
- trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
__preempt_count_sub(val);
}
EXPORT_SYMBOL(preempt_count_sub);
@@ -3280,7 +3197,6 @@ static void __sched notrace __schedule(bool preempt)
trace_sched_switch(preempt, prev, next);
rq = context_switch(rq, prev, next); /* unlocks the rq */
- cpu = cpu_of(rq);
} else {
lockdep_unpin_lock(&rq->lock);
raw_spin_unlock_irq(&rq->lock);
@@ -3466,7 +3382,7 @@ EXPORT_SYMBOL(default_wake_function);
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
- int oldprio, queued, running, enqueue_flag = ENQUEUE_RESTORE;
+ int oldprio, queued, running, queue_flag = DEQUEUE_SAVE | DEQUEUE_MOVE;
struct rq *rq;
const struct sched_class *prev_class;
@@ -3494,11 +3410,15 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
trace_sched_pi_setprio(p, prio);
oldprio = p->prio;
+
+ if (oldprio == prio)
+ queue_flag &= ~DEQUEUE_MOVE;
+
prev_class = p->sched_class;
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, queue_flag);
if (running)
put_prev_task(rq, p);
@@ -3516,7 +3436,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (!dl_prio(p->normal_prio) ||
(pi_task && dl_entity_preempt(&pi_task->dl, &p->dl))) {
p->dl.dl_boosted = 1;
- enqueue_flag |= ENQUEUE_REPLENISH;
+ queue_flag |= ENQUEUE_REPLENISH;
} else
p->dl.dl_boosted = 0;
p->sched_class = &dl_sched_class;
@@ -3524,7 +3444,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (dl_prio(oldprio))
p->dl.dl_boosted = 0;
if (oldprio < prio)
- enqueue_flag |= ENQUEUE_HEAD;
+ queue_flag |= ENQUEUE_HEAD;
p->sched_class = &rt_sched_class;
} else {
if (dl_prio(oldprio))
@@ -3539,7 +3459,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (running)
p->sched_class->set_curr_task(rq);
if (queued)
- enqueue_task(rq, p, enqueue_flag);
+ enqueue_task(rq, p, queue_flag);
check_class_changed(rq, p, prev_class, oldprio);
out_unlock:
@@ -3895,6 +3815,7 @@ static int __sched_setscheduler(struct task_struct *p,
const struct sched_class *prev_class;
struct rq *rq;
int reset_on_fork;
+ int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
@@ -4077,17 +3998,14 @@ change:
* itself.
*/
new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
- if (new_effective_prio == oldprio) {
- __setscheduler_params(p, attr);
- task_rq_unlock(rq, p, &flags);
- return 0;
- }
+ if (new_effective_prio == oldprio)
+ queue_flags &= ~DEQUEUE_MOVE;
}
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, queue_flags);
if (running)
put_prev_task(rq, p);
@@ -4097,15 +4015,14 @@ change:
if (running)
p->sched_class->set_curr_task(rq);
if (queued) {
- int enqueue_flags = ENQUEUE_RESTORE;
/*
* We enqueue to tail when the priority of a task is
* increased (user space view).
*/
- if (oldprio <= p->prio)
- enqueue_flags |= ENQUEUE_HEAD;
+ if (oldprio < p->prio)
+ queue_flags |= ENQUEUE_HEAD;
- enqueue_task(rq, p, enqueue_flags);
+ enqueue_task(rq, p, queue_flags);
}
check_class_changed(rq, p, prev_class, oldprio);
@@ -5096,6 +5013,8 @@ void init_idle(struct task_struct *idle, int cpu)
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
+ kasan_unpoison_task_stack(idle);
+
#ifdef CONFIG_SMP
/*
* Its possible that init_idle() gets called multiple times on a task,
@@ -5405,183 +5324,6 @@ static void migrate_tasks(struct rq *dead_rq)
}
#endif /* CONFIG_HOTPLUG_CPU */
-#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
-
-static struct ctl_table sd_ctl_dir[] = {
- {
- .procname = "sched_domain",
- .mode = 0555,
- },
- {}
-};
-
-static struct ctl_table sd_ctl_root[] = {
- {
- .procname = "kernel",
- .mode = 0555,
- .child = sd_ctl_dir,
- },
- {}
-};
-
-static struct ctl_table *sd_alloc_ctl_entry(int n)
-{
- struct ctl_table *entry =
- kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
-
- return entry;
-}
-
-static void sd_free_ctl_entry(struct ctl_table **tablep)
-{
- struct ctl_table *entry;
-
- /*
- * In the intermediate directories, both the child directory and
- * procname are dynamically allocated and could fail but the mode
- * will always be set. In the lowest directory the names are
- * static strings and all have proc handlers.
- */
- for (entry = *tablep; entry->mode; entry++) {
- if (entry->child)
- sd_free_ctl_entry(&entry->child);
- if (entry->proc_handler == NULL)
- kfree(entry->procname);
- }
-
- kfree(*tablep);
- *tablep = NULL;
-}
-
-static int min_load_idx = 0;
-static int max_load_idx = CPU_LOAD_IDX_MAX-1;
-
-static void
-set_table_entry(struct ctl_table *entry,
- const char *procname, void *data, int maxlen,
- umode_t mode, proc_handler *proc_handler,
- bool load_idx)
-{
- entry->procname = procname;
- entry->data = data;
- entry->maxlen = maxlen;
- entry->mode = mode;
- entry->proc_handler = proc_handler;
-
- if (load_idx) {
- entry->extra1 = &min_load_idx;
- entry->extra2 = &max_load_idx;
- }
-}
-
-static struct ctl_table *
-sd_alloc_ctl_domain_table(struct sched_domain *sd)
-{
- struct ctl_table *table = sd_alloc_ctl_entry(14);
-
- if (table == NULL)
- return NULL;
-
- set_table_entry(&table[0], "min_interval", &sd->min_interval,
- sizeof(long), 0644, proc_doulongvec_minmax, false);
- set_table_entry(&table[1], "max_interval", &sd->max_interval,
- sizeof(long), 0644, proc_doulongvec_minmax, false);
- set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[9], "cache_nice_tries",
- &sd->cache_nice_tries,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[10], "flags", &sd->flags,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[11], "max_newidle_lb_cost",
- &sd->max_newidle_lb_cost,
- sizeof(long), 0644, proc_doulongvec_minmax, false);
- set_table_entry(&table[12], "name", sd->name,
- CORENAME_MAX_SIZE, 0444, proc_dostring, false);
- /* &table[13] is terminator */
-
- return table;
-}
-
-static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
-{
- struct ctl_table *entry, *table;
- struct sched_domain *sd;
- int domain_num = 0, i;
- char buf[32];
-
- for_each_domain(cpu, sd)
- domain_num++;
- entry = table = sd_alloc_ctl_entry(domain_num + 1);
- if (table == NULL)
- return NULL;
-
- i = 0;
- for_each_domain(cpu, sd) {
- snprintf(buf, 32, "domain%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_domain_table(sd);
- entry++;
- i++;
- }
- return table;
-}
-
-static struct ctl_table_header *sd_sysctl_header;
-static void register_sched_domain_sysctl(void)
-{
- int i, cpu_num = num_possible_cpus();
- struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
- char buf[32];
-
- WARN_ON(sd_ctl_dir[0].child);
- sd_ctl_dir[0].child = entry;
-
- if (entry == NULL)
- return;
-
- for_each_possible_cpu(i) {
- snprintf(buf, 32, "cpu%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_cpu_table(i);
- entry++;
- }
-
- WARN_ON(sd_sysctl_header);
- sd_sysctl_header = register_sysctl_table(sd_ctl_root);
-}
-
-/* may be called multiple times per register */
-static void unregister_sched_domain_sysctl(void)
-{
- unregister_sysctl_table(sd_sysctl_header);
- sd_sysctl_header = NULL;
- if (sd_ctl_dir[0].child)
- sd_free_ctl_entry(&sd_ctl_dir[0].child);
-}
-#else
-static void register_sched_domain_sysctl(void)
-{
-}
-static void unregister_sched_domain_sysctl(void)
-{
-}
-#endif /* CONFIG_SCHED_DEBUG && CONFIG_SYSCTL */
-
static void set_rq_online(struct rq *rq)
{
if (!rq->online) {
@@ -5692,16 +5434,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
set_cpu_rq_start_time();
return NOTIFY_OK;
- case CPU_ONLINE:
- /*
- * At this point a starting CPU has marked itself as online via
- * set_cpu_online(). But it might not yet have marked itself
- * as active, which is essential from here on.
- */
- set_cpu_active(cpu, true);
- stop_machine_unpark(cpu);
- return NOTIFY_OK;
-
case CPU_DOWN_FAILED:
set_cpu_active(cpu, true);
return NOTIFY_OK;
@@ -6173,11 +5905,16 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
/* Setup the mask of cpus configured for isolated domains */
static int __init isolated_cpu_setup(char *str)
{
+ int ret;
+
alloc_bootmem_cpumask_var(&cpu_isolated_map);
- cpulist_parse(str, cpu_isolated_map);
+ ret = cpulist_parse(str, cpu_isolated_map);
+ if (ret) {
+ pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids);
+ return 0;
+ }
return 1;
}
-
__setup("isolcpus=", isolated_cpu_setup);
struct s_data {
@@ -7860,11 +7597,9 @@ void sched_destroy_group(struct task_group *tg)
void sched_offline_group(struct task_group *tg)
{
unsigned long flags;
- int i;
/* end participation in shares distribution */
- for_each_possible_cpu(i)
- unregister_fair_sched_group(tg, i);
+ unregister_fair_sched_group(tg);
spin_lock_irqsave(&task_group_lock, flags);
list_del_rcu(&tg->list);
@@ -7890,7 +7625,7 @@ void sched_move_task(struct task_struct *tsk)
queued = task_on_rq_queued(tsk);
if (queued)
- dequeue_task(rq, tsk, DEQUEUE_SAVE);
+ dequeue_task(rq, tsk, DEQUEUE_SAVE | DEQUEUE_MOVE);
if (unlikely(running))
put_prev_task(rq, tsk);
@@ -7914,7 +7649,7 @@ void sched_move_task(struct task_struct *tsk)
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (queued)
- enqueue_task(rq, tsk, ENQUEUE_RESTORE);
+ enqueue_task(rq, tsk, ENQUEUE_RESTORE | ENQUEUE_MOVE);
task_rq_unlock(rq, tsk, &flags);
}
diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c
new file mode 100644
index 000000000000..928c4ba32f68
--- /dev/null
+++ b/kernel/sched/cpufreq.c
@@ -0,0 +1,37 @@
+/*
+ * Scheduler code and data structures related to cpufreq.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "sched.h"
+
+DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_set_update_util_data - Populate the CPU's update_util_data pointer.
+ * @cpu: The CPU to set the pointer for.
+ * @data: New pointer value.
+ *
+ * Set and publish the update_util_data pointer for the given CPU. That pointer
+ * points to a struct update_util_data object containing a callback function
+ * to call from cpufreq_update_util(). That function will be called from an RCU
+ * read-side critical section, so it must not sleep.
+ *
+ * Callers must use RCU-sched callbacks to free any memory that might be
+ * accessed via the old update_util_data pointer or invoke synchronize_sched()
+ * right after this function to avoid use-after-free.
+ */
+void cpufreq_set_update_util_data(int cpu, struct update_util_data *data)
+{
+ if (WARN_ON(data && !data->func))
+ return;
+
+ rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
+}
+EXPORT_SYMBOL_GPL(cpufreq_set_update_util_data);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index b2ab2ffb1adc..75f98c5498d5 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -262,21 +262,21 @@ static __always_inline bool steal_account_process_tick(void)
#ifdef CONFIG_PARAVIRT
if (static_key_false(&paravirt_steal_enabled)) {
u64 steal;
- cputime_t steal_ct;
+ unsigned long steal_jiffies;
steal = paravirt_steal_clock(smp_processor_id());
steal -= this_rq()->prev_steal_time;
/*
- * cputime_t may be less precise than nsecs (eg: if it's
- * based on jiffies). Lets cast the result to cputime
+ * steal is in nsecs but our caller is expecting steal
+ * time in jiffies. Lets cast the result to jiffies
* granularity and account the rest on the next rounds.
*/
- steal_ct = nsecs_to_cputime(steal);
- this_rq()->prev_steal_time += cputime_to_nsecs(steal_ct);
+ steal_jiffies = nsecs_to_jiffies(steal);
+ this_rq()->prev_steal_time += jiffies_to_nsecs(steal_jiffies);
- account_steal_time(steal_ct);
- return steal_ct;
+ account_steal_time(jiffies_to_cputime(steal_jiffies));
+ return steal_jiffies;
}
#endif
return false;
@@ -668,26 +668,25 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-static unsigned long long vtime_delta(struct task_struct *tsk)
+static cputime_t vtime_delta(struct task_struct *tsk)
{
- unsigned long long clock;
+ unsigned long now = READ_ONCE(jiffies);
- clock = local_clock();
- if (clock < tsk->vtime_snap)
+ if (time_before(now, (unsigned long)tsk->vtime_snap))
return 0;
- return clock - tsk->vtime_snap;
+ return jiffies_to_cputime(now - tsk->vtime_snap);
}
static cputime_t get_vtime_delta(struct task_struct *tsk)
{
- unsigned long long delta = vtime_delta(tsk);
+ unsigned long now = READ_ONCE(jiffies);
+ unsigned long delta = now - tsk->vtime_snap;
WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_INACTIVE);
- tsk->vtime_snap += delta;
+ tsk->vtime_snap = now;
- /* CHECKME: always safe to convert nsecs to cputime? */
- return nsecs_to_cputime(delta);
+ return jiffies_to_cputime(delta);
}
static void __vtime_account_system(struct task_struct *tsk)
@@ -699,6 +698,9 @@ static void __vtime_account_system(struct task_struct *tsk)
void vtime_account_system(struct task_struct *tsk)
{
+ if (!vtime_delta(tsk))
+ return;
+
write_seqcount_begin(&tsk->vtime_seqcount);
__vtime_account_system(tsk);
write_seqcount_end(&tsk->vtime_seqcount);
@@ -707,7 +709,8 @@ void vtime_account_system(struct task_struct *tsk)
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
write_seqcount_end(&tsk->vtime_seqcount);
@@ -718,16 +721,19 @@ void vtime_account_user(struct task_struct *tsk)
cputime_t delta_cpu;
write_seqcount_begin(&tsk->vtime_seqcount);
- delta_cpu = get_vtime_delta(tsk);
tsk->vtime_snap_whence = VTIME_SYS;
- account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+ if (vtime_delta(tsk)) {
+ delta_cpu = get_vtime_delta(tsk);
+ account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+ }
write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_user_enter(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
write_seqcount_end(&tsk->vtime_seqcount);
}
@@ -742,7 +748,8 @@ void vtime_guest_enter(struct task_struct *tsk)
* that can thus safely catch up with a tickless delta.
*/
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
current->flags |= PF_VCPU;
write_seqcount_end(&tsk->vtime_seqcount);
}
@@ -772,7 +779,7 @@ void arch_vtime_task_switch(struct task_struct *prev)
write_seqcount_begin(&current->vtime_seqcount);
current->vtime_snap_whence = VTIME_SYS;
- current->vtime_snap = sched_clock_cpu(smp_processor_id());
+ current->vtime_snap = jiffies;
write_seqcount_end(&current->vtime_seqcount);
}
@@ -783,7 +790,7 @@ void vtime_init_idle(struct task_struct *t, int cpu)
local_irq_save(flags);
write_seqcount_begin(&t->vtime_seqcount);
t->vtime_snap_whence = VTIME_SYS;
- t->vtime_snap = sched_clock_cpu(cpu);
+ t->vtime_snap = jiffies;
write_seqcount_end(&t->vtime_seqcount);
local_irq_restore(flags);
}
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index cd64c979d0e1..affd97ec9f65 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -352,7 +352,15 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
- WARN_ON(!dl_se->dl_new || dl_se->dl_throttled);
+ WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
+
+ /*
+ * We are racing with the deadline timer. So, do nothing because
+ * the deadline timer handler will take care of properly recharging
+ * the runtime and postponing the deadline
+ */
+ if (dl_se->dl_throttled)
+ return;
/*
* We use the regular wall clock time to set deadlines in the
@@ -361,7 +369,6 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
*/
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
dl_se->runtime = pi_se->dl_runtime;
- dl_se->dl_new = 0;
}
/*
@@ -399,6 +406,9 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
dl_se->runtime = pi_se->dl_runtime;
}
+ if (dl_se->dl_yielded && dl_se->runtime > 0)
+ dl_se->runtime = 0;
+
/*
* We keep moving the deadline away until we get some
* available runtime for the entity. This ensures correct
@@ -420,7 +430,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
* entity.
*/
if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
- printk_deferred_once("sched: DL replenish lagged to much\n");
+ printk_deferred_once("sched: DL replenish lagged too much\n");
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
dl_se->runtime = pi_se->dl_runtime;
}
@@ -500,15 +510,6 @@ static void update_dl_entity(struct sched_dl_entity *dl_se,
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
- /*
- * The arrival of a new instance needs special treatment, i.e.,
- * the actual scheduling parameters have to be "renewed".
- */
- if (dl_se->dl_new) {
- setup_new_dl_entity(dl_se, pi_se);
- return;
- }
-
if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
@@ -605,16 +606,6 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
}
/*
- * This is possible if switched_from_dl() raced against a running
- * callback that took the above !dl_task() path and we've since then
- * switched back into SCHED_DEADLINE.
- *
- * There's nothing to do except drop our task reference.
- */
- if (dl_se->dl_new)
- goto unlock;
-
- /*
* The task might have been boosted by someone else and might be in the
* boosting/deboosting path, its not throttled.
*/
@@ -726,6 +717,10 @@ static void update_curr_dl(struct rq *rq)
if (!dl_task(curr) || !on_dl_rq(dl_se))
return;
+ /* Kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
/*
* Consumed budget is computed considering the time as
* observed by schedulable tasks (excluding time spent
@@ -735,8 +730,11 @@ static void update_curr_dl(struct rq *rq)
* approach need further study.
*/
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
- if (unlikely((s64)delta_exec <= 0))
+ if (unlikely((s64)delta_exec <= 0)) {
+ if (unlikely(dl_se->dl_yielded))
+ goto throttle;
return;
+ }
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
@@ -749,8 +747,10 @@ static void update_curr_dl(struct rq *rq)
sched_rt_avg_update(rq, delta_exec);
- dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec;
- if (dl_runtime_exceeded(dl_se)) {
+ dl_se->runtime -= delta_exec;
+
+throttle:
+ if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) {
dl_se->dl_throttled = 1;
__dequeue_task_dl(rq, curr, 0);
if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr)))
@@ -917,7 +917,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
* parameters of the task might need updating. Otherwise,
* we want a replenishment of its runtime.
*/
- if (dl_se->dl_new || flags & ENQUEUE_WAKEUP)
+ if (flags & ENQUEUE_WAKEUP)
update_dl_entity(dl_se, pi_se);
else if (flags & ENQUEUE_REPLENISH)
replenish_dl_entity(dl_se, pi_se);
@@ -994,18 +994,14 @@ static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags)
*/
static void yield_task_dl(struct rq *rq)
{
- struct task_struct *p = rq->curr;
-
/*
* We make the task go to sleep until its current deadline by
* forcing its runtime to zero. This way, update_curr_dl() stops
* it and the bandwidth timer will wake it up and will give it
* new scheduling parameters (thanks to dl_yielded=1).
*/
- if (p->dl.runtime > 0) {
- rq->curr->dl.dl_yielded = 1;
- p->dl.runtime = 0;
- }
+ rq->curr->dl.dl_yielded = 1;
+
update_rq_clock(rq);
update_curr_dl(rq);
/*
@@ -1722,6 +1718,9 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p)
*/
static void switched_to_dl(struct rq *rq, struct task_struct *p)
{
+ if (dl_time_before(p->dl.deadline, rq_clock(rq)))
+ setup_new_dl_entity(&p->dl, &p->dl);
+
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)
@@ -1768,8 +1767,7 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
*/
resched_curr(rq);
#endif /* CONFIG_SMP */
- } else
- switched_to_dl(rq, p);
+ }
}
const struct sched_class dl_sched_class = {
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 641511771ae6..4fbc3bd5ff60 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -16,6 +16,7 @@
#include <linux/kallsyms.h>
#include <linux/utsname.h>
#include <linux/mempolicy.h>
+#include <linux/debugfs.h>
#include "sched.h"
@@ -58,6 +59,309 @@ static unsigned long nsec_low(unsigned long long nsec)
#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
+#define SCHED_FEAT(name, enabled) \
+ #name ,
+
+static const char * const sched_feat_names[] = {
+#include "features.h"
+};
+
+#undef SCHED_FEAT
+
+static int sched_feat_show(struct seq_file *m, void *v)
+{
+ int i;
+
+ for (i = 0; i < __SCHED_FEAT_NR; i++) {
+ if (!(sysctl_sched_features & (1UL << i)))
+ seq_puts(m, "NO_");
+ seq_printf(m, "%s ", sched_feat_names[i]);
+ }
+ seq_puts(m, "\n");
+
+ return 0;
+}
+
+#ifdef HAVE_JUMP_LABEL
+
+#define jump_label_key__true STATIC_KEY_INIT_TRUE
+#define jump_label_key__false STATIC_KEY_INIT_FALSE
+
+#define SCHED_FEAT(name, enabled) \
+ jump_label_key__##enabled ,
+
+struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
+#include "features.h"
+};
+
+#undef SCHED_FEAT
+
+static void sched_feat_disable(int i)
+{
+ static_key_disable(&sched_feat_keys[i]);
+}
+
+static void sched_feat_enable(int i)
+{
+ static_key_enable(&sched_feat_keys[i]);
+}
+#else
+static void sched_feat_disable(int i) { };
+static void sched_feat_enable(int i) { };
+#endif /* HAVE_JUMP_LABEL */
+
+static int sched_feat_set(char *cmp)
+{
+ int i;
+ int neg = 0;
+
+ if (strncmp(cmp, "NO_", 3) == 0) {
+ neg = 1;
+ cmp += 3;
+ }
+
+ for (i = 0; i < __SCHED_FEAT_NR; i++) {
+ if (strcmp(cmp, sched_feat_names[i]) == 0) {
+ if (neg) {
+ sysctl_sched_features &= ~(1UL << i);
+ sched_feat_disable(i);
+ } else {
+ sysctl_sched_features |= (1UL << i);
+ sched_feat_enable(i);
+ }
+ break;
+ }
+ }
+
+ return i;
+}
+
+static ssize_t
+sched_feat_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ char *cmp;
+ int i;
+ struct inode *inode;
+
+ if (cnt > 63)
+ cnt = 63;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+ cmp = strstrip(buf);
+
+ /* Ensure the static_key remains in a consistent state */
+ inode = file_inode(filp);
+ inode_lock(inode);
+ i = sched_feat_set(cmp);
+ inode_unlock(inode);
+ if (i == __SCHED_FEAT_NR)
+ return -EINVAL;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int sched_feat_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_feat_show, NULL);
+}
+
+static const struct file_operations sched_feat_fops = {
+ .open = sched_feat_open,
+ .write = sched_feat_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static __init int sched_init_debug(void)
+{
+ debugfs_create_file("sched_features", 0644, NULL, NULL,
+ &sched_feat_fops);
+
+ return 0;
+}
+late_initcall(sched_init_debug);
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_SYSCTL
+
+static struct ctl_table sd_ctl_dir[] = {
+ {
+ .procname = "sched_domain",
+ .mode = 0555,
+ },
+ {}
+};
+
+static struct ctl_table sd_ctl_root[] = {
+ {
+ .procname = "kernel",
+ .mode = 0555,
+ .child = sd_ctl_dir,
+ },
+ {}
+};
+
+static struct ctl_table *sd_alloc_ctl_entry(int n)
+{
+ struct ctl_table *entry =
+ kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
+
+ return entry;
+}
+
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+ struct ctl_table *entry;
+
+ /*
+ * In the intermediate directories, both the child directory and
+ * procname are dynamically allocated and could fail but the mode
+ * will always be set. In the lowest directory the names are
+ * static strings and all have proc handlers.
+ */
+ for (entry = *tablep; entry->mode; entry++) {
+ if (entry->child)
+ sd_free_ctl_entry(&entry->child);
+ if (entry->proc_handler == NULL)
+ kfree(entry->procname);
+ }
+
+ kfree(*tablep);
+ *tablep = NULL;
+}
+
+static int min_load_idx = 0;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
+
+static void
+set_table_entry(struct ctl_table *entry,
+ const char *procname, void *data, int maxlen,
+ umode_t mode, proc_handler *proc_handler,
+ bool load_idx)
+{
+ entry->procname = procname;
+ entry->data = data;
+ entry->maxlen = maxlen;
+ entry->mode = mode;
+ entry->proc_handler = proc_handler;
+
+ if (load_idx) {
+ entry->extra1 = &min_load_idx;
+ entry->extra2 = &max_load_idx;
+ }
+}
+
+static struct ctl_table *
+sd_alloc_ctl_domain_table(struct sched_domain *sd)
+{
+ struct ctl_table *table = sd_alloc_ctl_entry(14);
+
+ if (table == NULL)
+ return NULL;
+
+ set_table_entry(&table[0], "min_interval", &sd->min_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[1], "max_interval", &sd->max_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[9], "cache_nice_tries",
+ &sd->cache_nice_tries,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[10], "flags", &sd->flags,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[11], "max_newidle_lb_cost",
+ &sd->max_newidle_lb_cost,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[12], "name", sd->name,
+ CORENAME_MAX_SIZE, 0444, proc_dostring, false);
+ /* &table[13] is terminator */
+
+ return table;
+}
+
+static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
+{
+ struct ctl_table *entry, *table;
+ struct sched_domain *sd;
+ int domain_num = 0, i;
+ char buf[32];
+
+ for_each_domain(cpu, sd)
+ domain_num++;
+ entry = table = sd_alloc_ctl_entry(domain_num + 1);
+ if (table == NULL)
+ return NULL;
+
+ i = 0;
+ for_each_domain(cpu, sd) {
+ snprintf(buf, 32, "domain%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_domain_table(sd);
+ entry++;
+ i++;
+ }
+ return table;
+}
+
+static struct ctl_table_header *sd_sysctl_header;
+void register_sched_domain_sysctl(void)
+{
+ int i, cpu_num = num_possible_cpus();
+ struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
+ char buf[32];
+
+ WARN_ON(sd_ctl_dir[0].child);
+ sd_ctl_dir[0].child = entry;
+
+ if (entry == NULL)
+ return;
+
+ for_each_possible_cpu(i) {
+ snprintf(buf, 32, "cpu%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_cpu_table(i);
+ entry++;
+ }
+
+ WARN_ON(sd_sysctl_header);
+ sd_sysctl_header = register_sysctl_table(sd_ctl_root);
+}
+
+/* may be called multiple times per register */
+void unregister_sched_domain_sysctl(void)
+{
+ unregister_sysctl_table(sd_sysctl_header);
+ sd_sysctl_header = NULL;
+ if (sd_ctl_dir[0].child)
+ sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
+#endif /* CONFIG_SYSCTL */
+#endif /* CONFIG_SMP */
+
#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
{
@@ -75,16 +379,18 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
- PN(se->statistics.wait_start);
- PN(se->statistics.sleep_start);
- PN(se->statistics.block_start);
- PN(se->statistics.sleep_max);
- PN(se->statistics.block_max);
- PN(se->statistics.exec_max);
- PN(se->statistics.slice_max);
- PN(se->statistics.wait_max);
- PN(se->statistics.wait_sum);
- P(se->statistics.wait_count);
+ if (schedstat_enabled()) {
+ PN(se->statistics.wait_start);
+ PN(se->statistics.sleep_start);
+ PN(se->statistics.block_start);
+ PN(se->statistics.sleep_max);
+ PN(se->statistics.block_max);
+ PN(se->statistics.exec_max);
+ PN(se->statistics.slice_max);
+ PN(se->statistics.wait_max);
+ PN(se->statistics.wait_sum);
+ P(se->statistics.wait_count);
+ }
#endif
P(se->load.weight);
#ifdef CONFIG_SMP
@@ -122,10 +428,12 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
(long long)(p->nvcsw + p->nivcsw),
p->prio);
#ifdef CONFIG_SCHEDSTATS
- SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
- SPLIT_NS(p->se.statistics.wait_sum),
- SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.statistics.sum_sleep_runtime));
+ if (schedstat_enabled()) {
+ SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
+ SPLIT_NS(p->se.statistics.wait_sum),
+ SPLIT_NS(p->se.sum_exec_runtime),
+ SPLIT_NS(p->se.statistics.sum_sleep_runtime));
+ }
#else
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
0LL, 0L,
@@ -258,8 +566,17 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
{
+ struct dl_bw *dl_bw;
+
SEQ_printf(m, "\ndl_rq[%d]:\n", cpu);
SEQ_printf(m, " .%-30s: %ld\n", "dl_nr_running", dl_rq->dl_nr_running);
+#ifdef CONFIG_SMP
+ dl_bw = &cpu_rq(cpu)->rd->dl_bw;
+#else
+ dl_bw = &dl_rq->dl_bw;
+#endif
+ SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->bw", dl_bw->bw);
+ SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->total_bw", dl_bw->total_bw);
}
extern __read_mostly int sched_clock_running;
@@ -313,17 +630,18 @@ do { \
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
- P(yld_count);
-
- P(sched_count);
- P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
P64(max_idle_balance_cost);
#endif
- P(ttwu_count);
- P(ttwu_local);
+ if (schedstat_enabled()) {
+ P(yld_count);
+ P(sched_count);
+ P(sched_goidle);
+ P(ttwu_count);
+ P(ttwu_local);
+ }
#undef P
#undef P64
@@ -569,38 +887,39 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
- PN(se.statistics.sum_sleep_runtime);
- PN(se.statistics.wait_start);
- PN(se.statistics.sleep_start);
- PN(se.statistics.block_start);
- PN(se.statistics.sleep_max);
- PN(se.statistics.block_max);
- PN(se.statistics.exec_max);
- PN(se.statistics.slice_max);
- PN(se.statistics.wait_max);
- PN(se.statistics.wait_sum);
- P(se.statistics.wait_count);
- PN(se.statistics.iowait_sum);
- P(se.statistics.iowait_count);
P(se.nr_migrations);
- P(se.statistics.nr_migrations_cold);
- P(se.statistics.nr_failed_migrations_affine);
- P(se.statistics.nr_failed_migrations_running);
- P(se.statistics.nr_failed_migrations_hot);
- P(se.statistics.nr_forced_migrations);
- P(se.statistics.nr_wakeups);
- P(se.statistics.nr_wakeups_sync);
- P(se.statistics.nr_wakeups_migrate);
- P(se.statistics.nr_wakeups_local);
- P(se.statistics.nr_wakeups_remote);
- P(se.statistics.nr_wakeups_affine);
- P(se.statistics.nr_wakeups_affine_attempts);
- P(se.statistics.nr_wakeups_passive);
- P(se.statistics.nr_wakeups_idle);
- {
+ if (schedstat_enabled()) {
u64 avg_atom, avg_per_cpu;
+ PN(se.statistics.sum_sleep_runtime);
+ PN(se.statistics.wait_start);
+ PN(se.statistics.sleep_start);
+ PN(se.statistics.block_start);
+ PN(se.statistics.sleep_max);
+ PN(se.statistics.block_max);
+ PN(se.statistics.exec_max);
+ PN(se.statistics.slice_max);
+ PN(se.statistics.wait_max);
+ PN(se.statistics.wait_sum);
+ P(se.statistics.wait_count);
+ PN(se.statistics.iowait_sum);
+ P(se.statistics.iowait_count);
+ P(se.statistics.nr_migrations_cold);
+ P(se.statistics.nr_failed_migrations_affine);
+ P(se.statistics.nr_failed_migrations_running);
+ P(se.statistics.nr_failed_migrations_hot);
+ P(se.statistics.nr_forced_migrations);
+ P(se.statistics.nr_wakeups);
+ P(se.statistics.nr_wakeups_sync);
+ P(se.statistics.nr_wakeups_migrate);
+ P(se.statistics.nr_wakeups_local);
+ P(se.statistics.nr_wakeups_remote);
+ P(se.statistics.nr_wakeups_affine);
+ P(se.statistics.nr_wakeups_affine_attempts);
+ P(se.statistics.nr_wakeups_passive);
+ P(se.statistics.nr_wakeups_idle);
+
avg_atom = p->se.sum_exec_runtime;
if (nr_switches)
avg_atom = div64_ul(avg_atom, nr_switches);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 56b7d4b83947..46d64e4ccfde 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -20,8 +20,8 @@
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
*/
-#include <linux/latencytop.h>
#include <linux/sched.h>
+#include <linux/latencytop.h>
#include <linux/cpumask.h>
#include <linux/cpuidle.h>
#include <linux/slab.h>
@@ -755,7 +755,9 @@ static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
struct task_struct *p;
- u64 delta = rq_clock(rq_of(cfs_rq)) - se->statistics.wait_start;
+ u64 delta;
+
+ delta = rq_clock(rq_of(cfs_rq)) - se->statistics.wait_start;
if (entity_is_task(se)) {
p = task_of(se);
@@ -776,22 +778,12 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->statistics.wait_sum += delta;
se->statistics.wait_start = 0;
}
-#else
-static inline void
-update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-}
-
-static inline void
-update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-}
-#endif
/*
* Task is being enqueued - update stats:
*/
-static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static inline void
+update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
/*
* Are we enqueueing a waiting task? (for current tasks
@@ -802,7 +794,7 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
static inline void
-update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
/*
* Mark the end of the wait period if dequeueing a
@@ -810,8 +802,41 @@ update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
*/
if (se != cfs_rq->curr)
update_stats_wait_end(cfs_rq, se);
+
+ if (flags & DEQUEUE_SLEEP) {
+ if (entity_is_task(se)) {
+ struct task_struct *tsk = task_of(se);
+
+ if (tsk->state & TASK_INTERRUPTIBLE)
+ se->statistics.sleep_start = rq_clock(rq_of(cfs_rq));
+ if (tsk->state & TASK_UNINTERRUPTIBLE)
+ se->statistics.block_start = rq_clock(rq_of(cfs_rq));
+ }
+ }
+
+}
+#else
+static inline void
+update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+}
+
+static inline void
+update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
}
+static inline void
+update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+}
+
+static inline void
+update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
+{
+}
+#endif
+
/*
* We are picking a new current task - update its stats:
*/
@@ -907,10 +932,11 @@ struct numa_group {
spinlock_t lock; /* nr_tasks, tasks */
int nr_tasks;
pid_t gid;
+ int active_nodes;
struct rcu_head rcu;
- nodemask_t active_nodes;
unsigned long total_faults;
+ unsigned long max_faults_cpu;
/*
* Faults_cpu is used to decide whether memory should move
* towards the CPU. As a consequence, these stats are weighted
@@ -969,6 +995,18 @@ static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)];
}
+/*
+ * A node triggering more than 1/3 as many NUMA faults as the maximum is
+ * considered part of a numa group's pseudo-interleaving set. Migrations
+ * between these nodes are slowed down, to allow things to settle down.
+ */
+#define ACTIVE_NODE_FRACTION 3
+
+static bool numa_is_active_node(int nid, struct numa_group *ng)
+{
+ return group_faults_cpu(ng, nid) * ACTIVE_NODE_FRACTION > ng->max_faults_cpu;
+}
+
/* Handle placement on systems where not all nodes are directly connected. */
static unsigned long score_nearby_nodes(struct task_struct *p, int nid,
int maxdist, bool task)
@@ -1118,27 +1156,23 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
return true;
/*
- * Do not migrate if the destination is not a node that
- * is actively used by this numa group.
- */
- if (!node_isset(dst_nid, ng->active_nodes))
- return false;
-
- /*
- * Source is a node that is not actively used by this
- * numa group, while the destination is. Migrate.
+ * Destination node is much more heavily used than the source
+ * node? Allow migration.
*/
- if (!node_isset(src_nid, ng->active_nodes))
+ if (group_faults_cpu(ng, dst_nid) > group_faults_cpu(ng, src_nid) *
+ ACTIVE_NODE_FRACTION)
return true;
/*
- * Both source and destination are nodes in active
- * use by this numa group. Maximize memory bandwidth
- * by migrating from more heavily used groups, to less
- * heavily used ones, spreading the load around.
- * Use a 1/4 hysteresis to avoid spurious page movement.
+ * Distribute memory according to CPU & memory use on each node,
+ * with 3/4 hysteresis to avoid unnecessary memory migrations:
+ *
+ * faults_cpu(dst) 3 faults_cpu(src)
+ * --------------- * - > ---------------
+ * faults_mem(dst) 4 faults_mem(src)
*/
- return group_faults(p, dst_nid) < (group_faults(p, src_nid) * 3 / 4);
+ return group_faults_cpu(ng, dst_nid) * group_faults(p, src_nid) * 3 >
+ group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
}
static unsigned long weighted_cpuload(const int cpu);
@@ -1484,7 +1518,7 @@ static int task_numa_migrate(struct task_struct *p)
.best_task = NULL,
.best_imp = 0,
- .best_cpu = -1
+ .best_cpu = -1,
};
struct sched_domain *sd;
unsigned long taskweight, groupweight;
@@ -1536,8 +1570,7 @@ static int task_numa_migrate(struct task_struct *p)
* multiple NUMA nodes; in order to better consolidate the group,
* we need to check other locations.
*/
- if (env.best_cpu == -1 || (p->numa_group &&
- nodes_weight(p->numa_group->active_nodes) > 1)) {
+ if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) {
for_each_online_node(nid) {
if (nid == env.src_nid || nid == p->numa_preferred_nid)
continue;
@@ -1572,12 +1605,14 @@ static int task_numa_migrate(struct task_struct *p)
* trying for a better one later. Do not set the preferred node here.
*/
if (p->numa_group) {
+ struct numa_group *ng = p->numa_group;
+
if (env.best_cpu == -1)
nid = env.src_nid;
else
nid = env.dst_nid;
- if (node_isset(nid, p->numa_group->active_nodes))
+ if (ng->active_nodes > 1 && numa_is_active_node(env.dst_nid, ng))
sched_setnuma(p, env.dst_nid);
}
@@ -1627,20 +1662,15 @@ static void numa_migrate_preferred(struct task_struct *p)
}
/*
- * Find the nodes on which the workload is actively running. We do this by
+ * Find out how many nodes on the workload is actively running on. Do this by
* tracking the nodes from which NUMA hinting faults are triggered. This can
* be different from the set of nodes where the workload's memory is currently
* located.
- *
- * The bitmask is used to make smarter decisions on when to do NUMA page
- * migrations, To prevent flip-flopping, and excessive page migrations, nodes
- * are added when they cause over 6/16 of the maximum number of faults, but
- * only removed when they drop below 3/16.
*/
-static void update_numa_active_node_mask(struct numa_group *numa_group)
+static void numa_group_count_active_nodes(struct numa_group *numa_group)
{
unsigned long faults, max_faults = 0;
- int nid;
+ int nid, active_nodes = 0;
for_each_online_node(nid) {
faults = group_faults_cpu(numa_group, nid);
@@ -1650,12 +1680,12 @@ static void update_numa_active_node_mask(struct numa_group *numa_group)
for_each_online_node(nid) {
faults = group_faults_cpu(numa_group, nid);
- if (!node_isset(nid, numa_group->active_nodes)) {
- if (faults > max_faults * 6 / 16)
- node_set(nid, numa_group->active_nodes);
- } else if (faults < max_faults * 3 / 16)
- node_clear(nid, numa_group->active_nodes);
+ if (faults * ACTIVE_NODE_FRACTION > max_faults)
+ active_nodes++;
}
+
+ numa_group->max_faults_cpu = max_faults;
+ numa_group->active_nodes = active_nodes;
}
/*
@@ -1946,7 +1976,7 @@ static void task_numa_placement(struct task_struct *p)
update_task_scan_period(p, fault_types[0], fault_types[1]);
if (p->numa_group) {
- update_numa_active_node_mask(p->numa_group);
+ numa_group_count_active_nodes(p->numa_group);
spin_unlock_irq(group_lock);
max_nid = preferred_group_nid(p, max_group_nid);
}
@@ -1990,14 +2020,14 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
return;
atomic_set(&grp->refcount, 1);
+ grp->active_nodes = 1;
+ grp->max_faults_cpu = 0;
spin_lock_init(&grp->lock);
grp->gid = p->pid;
/* Second half of the array tracks nids where faults happen */
grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES *
nr_node_ids;
- node_set(task_node(current), grp->active_nodes);
-
for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
grp->faults[i] = p->numa_faults[i];
@@ -2111,6 +2141,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
bool migrated = flags & TNF_MIGRATED;
int cpu_node = task_node(current);
int local = !!(flags & TNF_FAULT_LOCAL);
+ struct numa_group *ng;
int priv;
if (!static_branch_likely(&sched_numa_balancing))
@@ -2151,9 +2182,10 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
* actively using should be counted as local. This allows the
* scan rate to slow down when a workload has settled down.
*/
- if (!priv && !local && p->numa_group &&
- node_isset(cpu_node, p->numa_group->active_nodes) &&
- node_isset(mem_node, p->numa_group->active_nodes))
+ ng = p->numa_group;
+ if (!priv && !local && ng && ng->active_nodes > 1 &&
+ numa_is_active_node(cpu_node, ng) &&
+ numa_is_active_node(mem_node, ng))
local = 1;
task_numa_placement(p);
@@ -2824,7 +2856,8 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
{
struct cfs_rq *cfs_rq = cfs_rq_of(se);
u64 now = cfs_rq_clock_task(cfs_rq);
- int cpu = cpu_of(rq_of(cfs_rq));
+ struct rq *rq = rq_of(cfs_rq);
+ int cpu = cpu_of(rq);
/*
* Track task load average for carrying it to new CPU after migrated, and
@@ -2836,6 +2869,29 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
update_tg_load_avg(cfs_rq, 0);
+
+ if (cpu == smp_processor_id() && &rq->cfs == cfs_rq) {
+ unsigned long max = rq->cpu_capacity_orig;
+
+ /*
+ * There are a few boundary cases this might miss but it should
+ * get called often enough that that should (hopefully) not be
+ * a real problem -- added to that it only calls on the local
+ * CPU, so if we enqueue remotely we'll miss an update, but
+ * the next tick/schedule should update.
+ *
+ * It will not get called when we go idle, because the idle
+ * thread is a different class (!fair), nor will the utilization
+ * number include things like RT tasks.
+ *
+ * As is, the util number is not freq-invariant (we'd have to
+ * implement arch_scale_freq_capacity() for that).
+ *
+ * See cpu_util().
+ */
+ cpufreq_update_util(rq_clock(rq),
+ min(cfs_rq->avg.util_avg, max), max);
+ }
}
static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -3102,6 +3158,26 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
+static inline void check_schedstat_required(void)
+{
+#ifdef CONFIG_SCHEDSTATS
+ if (schedstat_enabled())
+ return;
+
+ /* Force schedstat enabled if a dependent tracepoint is active */
+ if (trace_sched_stat_wait_enabled() ||
+ trace_sched_stat_sleep_enabled() ||
+ trace_sched_stat_iowait_enabled() ||
+ trace_sched_stat_blocked_enabled() ||
+ trace_sched_stat_runtime_enabled()) {
+ pr_warn_once("Scheduler tracepoints stat_sleep, stat_iowait, "
+ "stat_blocked and stat_runtime require the "
+ "kernel parameter schedstats=enabled or "
+ "kernel.sched_schedstats=1\n");
+ }
+#endif
+}
+
static void
enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
@@ -3122,11 +3198,15 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
if (flags & ENQUEUE_WAKEUP) {
place_entity(cfs_rq, se, 0);
- enqueue_sleeper(cfs_rq, se);
+ if (schedstat_enabled())
+ enqueue_sleeper(cfs_rq, se);
}
- update_stats_enqueue(cfs_rq, se);
- check_spread(cfs_rq, se);
+ check_schedstat_required();
+ if (schedstat_enabled()) {
+ update_stats_enqueue(cfs_rq, se);
+ check_spread(cfs_rq, se);
+ }
if (se != cfs_rq->curr)
__enqueue_entity(cfs_rq, se);
se->on_rq = 1;
@@ -3193,19 +3273,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
update_curr(cfs_rq);
dequeue_entity_load_avg(cfs_rq, se);
- update_stats_dequeue(cfs_rq, se);
- if (flags & DEQUEUE_SLEEP) {
-#ifdef CONFIG_SCHEDSTATS
- if (entity_is_task(se)) {
- struct task_struct *tsk = task_of(se);
-
- if (tsk->state & TASK_INTERRUPTIBLE)
- se->statistics.sleep_start = rq_clock(rq_of(cfs_rq));
- if (tsk->state & TASK_UNINTERRUPTIBLE)
- se->statistics.block_start = rq_clock(rq_of(cfs_rq));
- }
-#endif
- }
+ if (schedstat_enabled())
+ update_stats_dequeue(cfs_rq, se, flags);
clear_buddies(cfs_rq, se);
@@ -3279,7 +3348,8 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* a CPU. So account for the time it spent waiting on the
* runqueue.
*/
- update_stats_wait_end(cfs_rq, se);
+ if (schedstat_enabled())
+ update_stats_wait_end(cfs_rq, se);
__dequeue_entity(cfs_rq, se);
update_load_avg(se, 1);
}
@@ -3292,7 +3362,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* least twice that of our own weight (i.e. dont track it
* when there are only lesser-weight tasks around):
*/
- if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
+ if (schedstat_enabled() && rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
se->statistics.slice_max = max(se->statistics.slice_max,
se->sum_exec_runtime - se->prev_sum_exec_runtime);
}
@@ -3375,9 +3445,13 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
/* throttle cfs_rqs exceeding runtime */
check_cfs_rq_runtime(cfs_rq);
- check_spread(cfs_rq, prev);
+ if (schedstat_enabled()) {
+ check_spread(cfs_rq, prev);
+ if (prev->on_rq)
+ update_stats_wait_start(cfs_rq, prev);
+ }
+
if (prev->on_rq) {
- update_stats_wait_start(cfs_rq, prev);
/* Put 'current' back into the tree. */
__enqueue_entity(cfs_rq, prev);
/* in !on_rq case, update occurred at dequeue */
@@ -4459,9 +4533,17 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
/* scale is effectively 1 << i now, and >> i divides by scale */
- old_load = this_rq->cpu_load[i] - tickless_load;
+ old_load = this_rq->cpu_load[i];
old_load = decay_load_missed(old_load, pending_updates - 1, i);
- old_load += tickless_load;
+ if (tickless_load) {
+ old_load -= decay_load_missed(tickless_load, pending_updates - 1, i);
+ /*
+ * old_load can never be a negative value because a
+ * decayed tickless_load cannot be greater than the
+ * original tickless_load.
+ */
+ old_load += tickless_load;
+ }
new_load = this_load;
/*
* Round up the averaging division if load is increasing. This
@@ -4484,6 +4566,25 @@ static unsigned long weighted_cpuload(const int cpu)
}
#ifdef CONFIG_NO_HZ_COMMON
+static void __update_cpu_load_nohz(struct rq *this_rq,
+ unsigned long curr_jiffies,
+ unsigned long load,
+ int active)
+{
+ unsigned long pending_updates;
+
+ pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+ if (pending_updates) {
+ this_rq->last_load_update_tick = curr_jiffies;
+ /*
+ * In the regular NOHZ case, we were idle, this means load 0.
+ * In the NOHZ_FULL case, we were non-idle, we should consider
+ * its weighted load.
+ */
+ __update_cpu_load(this_rq, load, pending_updates, active);
+ }
+}
+
/*
* There is no sane way to deal with nohz on smp when using jiffies because the
* cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
@@ -4501,22 +4602,15 @@ static unsigned long weighted_cpuload(const int cpu)
* Called from nohz_idle_balance() to update the load ratings before doing the
* idle balance.
*/
-static void update_idle_cpu_load(struct rq *this_rq)
+static void update_cpu_load_idle(struct rq *this_rq)
{
- unsigned long curr_jiffies = READ_ONCE(jiffies);
- unsigned long load = weighted_cpuload(cpu_of(this_rq));
- unsigned long pending_updates;
-
/*
* bail if there's load or we're actually up-to-date.
*/
- if (load || curr_jiffies == this_rq->last_load_update_tick)
+ if (weighted_cpuload(cpu_of(this_rq)))
return;
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- this_rq->last_load_update_tick = curr_jiffies;
-
- __update_cpu_load(this_rq, load, pending_updates, 0);
+ __update_cpu_load_nohz(this_rq, READ_ONCE(jiffies), 0, 0);
}
/*
@@ -4527,22 +4621,12 @@ void update_cpu_load_nohz(int active)
struct rq *this_rq = this_rq();
unsigned long curr_jiffies = READ_ONCE(jiffies);
unsigned long load = active ? weighted_cpuload(cpu_of(this_rq)) : 0;
- unsigned long pending_updates;
if (curr_jiffies == this_rq->last_load_update_tick)
return;
raw_spin_lock(&this_rq->lock);
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- if (pending_updates) {
- this_rq->last_load_update_tick = curr_jiffies;
- /*
- * In the regular NOHZ case, we were idle, this means load 0.
- * In the NOHZ_FULL case, we were non-idle, we should consider
- * its weighted load.
- */
- __update_cpu_load(this_rq, load, pending_updates, active);
- }
+ __update_cpu_load_nohz(this_rq, curr_jiffies, load, active);
raw_spin_unlock(&this_rq->lock);
}
#endif /* CONFIG_NO_HZ */
@@ -4554,7 +4638,7 @@ void update_cpu_load_active(struct rq *this_rq)
{
unsigned long load = weighted_cpuload(cpu_of(this_rq));
/*
- * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
+ * See the mess around update_cpu_load_idle() / update_cpu_load_nohz().
*/
this_rq->last_load_update_tick = jiffies;
__update_cpu_load(this_rq, load, 1, 1);
@@ -7848,7 +7932,7 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
if (time_after_eq(jiffies, rq->next_balance)) {
raw_spin_lock_irq(&rq->lock);
update_rq_clock(rq);
- update_idle_cpu_load(rq);
+ update_cpu_load_idle(rq);
raw_spin_unlock_irq(&rq->lock);
rebalance_domains(rq, CPU_IDLE);
}
@@ -8234,11 +8318,8 @@ void free_fair_sched_group(struct task_group *tg)
for_each_possible_cpu(i) {
if (tg->cfs_rq)
kfree(tg->cfs_rq[i]);
- if (tg->se) {
- if (tg->se[i])
- remove_entity_load_avg(tg->se[i]);
+ if (tg->se)
kfree(tg->se[i]);
- }
}
kfree(tg->cfs_rq);
@@ -8286,21 +8367,29 @@ err:
return 0;
}
-void unregister_fair_sched_group(struct task_group *tg, int cpu)
+void unregister_fair_sched_group(struct task_group *tg)
{
- struct rq *rq = cpu_rq(cpu);
unsigned long flags;
+ struct rq *rq;
+ int cpu;
- /*
- * Only empty task groups can be destroyed; so we can speculatively
- * check on_list without danger of it being re-added.
- */
- if (!tg->cfs_rq[cpu]->on_list)
- return;
+ for_each_possible_cpu(cpu) {
+ if (tg->se[cpu])
+ remove_entity_load_avg(tg->se[cpu]);
- raw_spin_lock_irqsave(&rq->lock, flags);
- list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ /*
+ * Only empty task groups can be destroyed; so we can speculatively
+ * check on_list without danger of it being re-added.
+ */
+ if (!tg->cfs_rq[cpu]->on_list)
+ continue;
+
+ rq = cpu_rq(cpu);
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ }
}
void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
@@ -8382,7 +8471,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
return 1;
}
-void unregister_fair_sched_group(struct task_group *tg, int cpu) { }
+void unregister_fair_sched_group(struct task_group *tg) { }
#endif /* CONFIG_FAIR_GROUP_SCHED */
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 544a7133cbd1..bd12c6c714ec 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -4,6 +4,7 @@
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
+#include <linux/cpuhotplug.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
@@ -193,8 +194,6 @@ exit_idle:
rcu_idle_exit();
}
-DEFINE_PER_CPU(bool, cpu_dead_idle);
-
/*
* Generic idle loop implementation
*
@@ -221,10 +220,7 @@ static void cpu_idle_loop(void)
rmb();
if (cpu_is_offline(smp_processor_id())) {
- rcu_cpu_notify(NULL, CPU_DYING_IDLE,
- (void *)(long)smp_processor_id());
- smp_mb(); /* all activity before dead. */
- this_cpu_write(cpu_dead_idle, true);
+ cpuhp_report_idle_dead();
arch_cpu_idle_dead();
}
@@ -291,5 +287,6 @@ void cpu_startup_entry(enum cpuhp_state state)
boot_init_stack_canary();
#endif
arch_cpu_idle_prepare();
+ cpuhp_online_idle(state);
cpu_idle_loop();
}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8ec86abe0ea1..c41ea7ac1764 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -58,7 +58,15 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
raw_spin_lock(&rt_b->rt_runtime_lock);
if (!rt_b->rt_period_active) {
rt_b->rt_period_active = 1;
- hrtimer_forward_now(&rt_b->rt_period_timer, rt_b->rt_period);
+ /*
+ * SCHED_DEADLINE updates the bandwidth, as a run away
+ * RT task with a DL task could hog a CPU. But DL does
+ * not reset the period. If a deadline task was running
+ * without an RT task running, it can cause RT tasks to
+ * throttle when they start up. Kick the timer right away
+ * to update the period.
+ */
+ hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0));
hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
}
raw_spin_unlock(&rt_b->rt_runtime_lock);
@@ -436,7 +444,7 @@ static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
static inline int on_rt_rq(struct sched_rt_entity *rt_se)
{
- return !list_empty(&rt_se->run_list);
+ return rt_se->on_rq;
}
#ifdef CONFIG_RT_GROUP_SCHED
@@ -482,8 +490,8 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
return rt_se->my_q;
}
-static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);
-static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
{
@@ -499,7 +507,7 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
if (!rt_se)
enqueue_top_rt_rq(rt_rq);
else if (!on_rt_rq(rt_se))
- enqueue_rt_entity(rt_se, false);
+ enqueue_rt_entity(rt_se, 0);
if (rt_rq->highest_prio.curr < curr->prio)
resched_curr(rq);
@@ -516,7 +524,7 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
if (!rt_se)
dequeue_top_rt_rq(rt_rq);
else if (on_rt_rq(rt_se))
- dequeue_rt_entity(rt_se);
+ dequeue_rt_entity(rt_se, 0);
}
static inline int rt_rq_throttled(struct rt_rq *rt_rq)
@@ -945,6 +953,10 @@ static void update_curr_rt(struct rq *rq)
if (curr->sched_class != &rt_sched_class)
return;
+ /* Kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
if (unlikely((s64)delta_exec <= 0))
return;
@@ -1142,12 +1154,27 @@ unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
}
static inline
+unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
+{
+ struct rt_rq *group_rq = group_rt_rq(rt_se);
+ struct task_struct *tsk;
+
+ if (group_rq)
+ return group_rq->rr_nr_running;
+
+ tsk = rt_task_of(rt_se);
+
+ return (tsk->policy == SCHED_RR) ? 1 : 0;
+}
+
+static inline
void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
int prio = rt_se_prio(rt_se);
WARN_ON(!rt_prio(prio));
rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
inc_rt_prio(rt_rq, prio);
inc_rt_migration(rt_se, rt_rq);
@@ -1160,13 +1187,37 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
WARN_ON(!rt_rq->rt_nr_running);
rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
dec_rt_prio(rt_rq, rt_se_prio(rt_se));
dec_rt_migration(rt_se, rt_rq);
dec_rt_group(rt_se, rt_rq);
}
-static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
+/*
+ * Change rt_se->run_list location unless SAVE && !MOVE
+ *
+ * assumes ENQUEUE/DEQUEUE flags match
+ */
+static inline bool move_entity(unsigned int flags)
+{
+ if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
+ return false;
+
+ return true;
+}
+
+static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array)
+{
+ list_del_init(&rt_se->run_list);
+
+ if (list_empty(array->queue + rt_se_prio(rt_se)))
+ __clear_bit(rt_se_prio(rt_se), array->bitmap);
+
+ rt_se->on_list = 0;
+}
+
+static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
@@ -1179,26 +1230,37 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
* get throttled and the current group doesn't have any other
* active members.
*/
- if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
+ if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) {
+ if (rt_se->on_list)
+ __delist_rt_entity(rt_se, array);
return;
+ }
- if (head)
- list_add(&rt_se->run_list, queue);
- else
- list_add_tail(&rt_se->run_list, queue);
- __set_bit(rt_se_prio(rt_se), array->bitmap);
+ if (move_entity(flags)) {
+ WARN_ON_ONCE(rt_se->on_list);
+ if (flags & ENQUEUE_HEAD)
+ list_add(&rt_se->run_list, queue);
+ else
+ list_add_tail(&rt_se->run_list, queue);
+
+ __set_bit(rt_se_prio(rt_se), array->bitmap);
+ rt_se->on_list = 1;
+ }
+ rt_se->on_rq = 1;
inc_rt_tasks(rt_se, rt_rq);
}
-static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
+static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
- list_del_init(&rt_se->run_list);
- if (list_empty(array->queue + rt_se_prio(rt_se)))
- __clear_bit(rt_se_prio(rt_se), array->bitmap);
+ if (move_entity(flags)) {
+ WARN_ON_ONCE(!rt_se->on_list);
+ __delist_rt_entity(rt_se, array);
+ }
+ rt_se->on_rq = 0;
dec_rt_tasks(rt_se, rt_rq);
}
@@ -1207,7 +1269,7 @@ static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
* Because the prio of an upper entry depends on the lower
* entries, we must remove entries top - down.
*/
-static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
+static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct sched_rt_entity *back = NULL;
@@ -1220,31 +1282,31 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
for (rt_se = back; rt_se; rt_se = rt_se->back) {
if (on_rt_rq(rt_se))
- __dequeue_rt_entity(rt_se);
+ __dequeue_rt_entity(rt_se, flags);
}
}
-static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rq *rq = rq_of_rt_se(rt_se);
- dequeue_rt_stack(rt_se);
+ dequeue_rt_stack(rt_se, flags);
for_each_sched_rt_entity(rt_se)
- __enqueue_rt_entity(rt_se, head);
+ __enqueue_rt_entity(rt_se, flags);
enqueue_top_rt_rq(&rq->rt);
}
-static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rq *rq = rq_of_rt_se(rt_se);
- dequeue_rt_stack(rt_se);
+ dequeue_rt_stack(rt_se, flags);
for_each_sched_rt_entity(rt_se) {
struct rt_rq *rt_rq = group_rt_rq(rt_se);
if (rt_rq && rt_rq->rt_nr_running)
- __enqueue_rt_entity(rt_se, false);
+ __enqueue_rt_entity(rt_se, flags);
}
enqueue_top_rt_rq(&rq->rt);
}
@@ -1260,7 +1322,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
if (flags & ENQUEUE_WAKEUP)
rt_se->timeout = 0;
- enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
+ enqueue_rt_entity(rt_se, flags);
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
@@ -1271,7 +1333,7 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
struct sched_rt_entity *rt_se = &p->rt;
update_curr_rt(rq);
- dequeue_rt_entity(rt_se);
+ dequeue_rt_entity(rt_se, flags);
dequeue_pushable_task(rq, p);
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 10f16374df7f..382848a24ed9 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3,6 +3,7 @@
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/sched/deadline.h>
+#include <linux/binfmts.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
@@ -313,12 +314,11 @@ extern int tg_nop(struct task_group *tg, void *data);
extern void free_fair_sched_group(struct task_group *tg);
extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
-extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
+extern void unregister_fair_sched_group(struct task_group *tg);
extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
struct sched_entity *se, int cpu,
struct sched_entity *parent);
extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
-extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
@@ -450,6 +450,7 @@ static inline int rt_bandwidth_enabled(void)
struct rt_rq {
struct rt_prio_array active;
unsigned int rt_nr_running;
+ unsigned int rr_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
@@ -909,6 +910,18 @@ static inline unsigned int group_first_cpu(struct sched_group *group)
extern int group_balance_cpu(struct sched_group *sg);
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
+void register_sched_domain_sysctl(void);
+void unregister_sched_domain_sysctl(void);
+#else
+static inline void register_sched_domain_sysctl(void)
+{
+}
+static inline void unregister_sched_domain_sysctl(void)
+{
+}
+#endif
+
#else
static inline void sched_ttwu_pending(void) { }
@@ -1022,6 +1035,7 @@ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
extern struct static_key_false sched_numa_balancing;
+extern struct static_key_false sched_schedstats;
static inline u64 global_rt_period(void)
{
@@ -1130,18 +1144,40 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
extern const int sched_prio_to_weight[40];
extern const u32 sched_prio_to_wmult[40];
+/*
+ * {de,en}queue flags:
+ *
+ * DEQUEUE_SLEEP - task is no longer runnable
+ * ENQUEUE_WAKEUP - task just became runnable
+ *
+ * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
+ * are in a known state which allows modification. Such pairs
+ * should preserve as much state as possible.
+ *
+ * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
+ * in the runqueue.
+ *
+ * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
+ * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
+ * ENQUEUE_WAKING - sched_class::task_waking was called
+ *
+ */
+
+#define DEQUEUE_SLEEP 0x01
+#define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
+#define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
+
#define ENQUEUE_WAKEUP 0x01
-#define ENQUEUE_HEAD 0x02
+#define ENQUEUE_RESTORE 0x02
+#define ENQUEUE_MOVE 0x04
+
+#define ENQUEUE_HEAD 0x08
+#define ENQUEUE_REPLENISH 0x10
#ifdef CONFIG_SMP
-#define ENQUEUE_WAKING 0x04 /* sched_class::task_waking was called */
+#define ENQUEUE_WAKING 0x20
#else
#define ENQUEUE_WAKING 0x00
#endif
-#define ENQUEUE_REPLENISH 0x08
-#define ENQUEUE_RESTORE 0x10
-
-#define DEQUEUE_SLEEP 0x01
-#define DEQUEUE_SAVE 0x02
#define RETRY_TASK ((void *)-1UL)
@@ -1278,6 +1314,35 @@ unsigned long to_ratio(u64 period, u64 runtime);
extern void init_entity_runnable_average(struct sched_entity *se);
+#ifdef CONFIG_NO_HZ_FULL
+extern bool sched_can_stop_tick(struct rq *rq);
+
+/*
+ * Tick may be needed by tasks in the runqueue depending on their policy and
+ * requirements. If tick is needed, lets send the target an IPI to kick it out of
+ * nohz mode if necessary.
+ */
+static inline void sched_update_tick_dependency(struct rq *rq)
+{
+ int cpu;
+
+ if (!tick_nohz_full_enabled())
+ return;
+
+ cpu = cpu_of(rq);
+
+ if (!tick_nohz_full_cpu(cpu))
+ return;
+
+ if (sched_can_stop_tick(rq))
+ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
+ else
+ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
+}
+#else
+static inline void sched_update_tick_dependency(struct rq *rq) { }
+#endif
+
static inline void add_nr_running(struct rq *rq, unsigned count)
{
unsigned prev_nr = rq->nr_running;
@@ -1289,26 +1354,16 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
if (!rq->rd->overload)
rq->rd->overload = true;
#endif
-
-#ifdef CONFIG_NO_HZ_FULL
- if (tick_nohz_full_cpu(rq->cpu)) {
- /*
- * Tick is needed if more than one task runs on a CPU.
- * Send the target an IPI to kick it out of nohz mode.
- *
- * We assume that IPI implies full memory barrier and the
- * new value of rq->nr_running is visible on reception
- * from the target.
- */
- tick_nohz_full_kick_cpu(rq->cpu);
- }
-#endif
}
+
+ sched_update_tick_dependency(rq);
}
static inline void sub_nr_running(struct rq *rq, unsigned count)
{
rq->nr_running -= count;
+ /* Check if we still need preemption */
+ sched_update_tick_dependency(rq);
}
static inline void rq_last_tick_reset(struct rq *rq)
@@ -1738,3 +1793,51 @@ static inline u64 irq_time_read(int cpu)
}
#endif /* CONFIG_64BIT */
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
+
+#ifdef CONFIG_CPU_FREQ
+DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_update_util - Take a note about CPU utilization changes.
+ * @time: Current time.
+ * @util: Current utilization.
+ * @max: Utilization ceiling.
+ *
+ * This function is called by the scheduler on every invocation of
+ * update_load_avg() on the CPU whose utilization is being updated.
+ *
+ * It can only be called from RCU-sched read-side critical sections.
+ */
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
+{
+ struct update_util_data *data;
+
+ data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
+ if (data)
+ data->func(data, time, util, max);
+}
+
+/**
+ * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
+ * @time: Current time.
+ *
+ * The way cpufreq is currently arranged requires it to evaluate the CPU
+ * performance state (frequency/voltage) on a regular basis to prevent it from
+ * being stuck in a completely inadequate performance level for too long.
+ * That is not guaranteed to happen if the updates are only triggered from CFS,
+ * though, because they may not be coming in if RT or deadline tasks are active
+ * all the time (or there are RT and DL tasks only).
+ *
+ * As a workaround for that issue, this function is called by the RT and DL
+ * sched classes to trigger extra cpufreq updates to prevent it from stalling,
+ * but that really is a band-aid. Going forward it should be replaced with
+ * solutions targeted more specifically at RT and DL tasks.
+ */
+static inline void cpufreq_trigger_update(u64 time)
+{
+ cpufreq_update_util(time, ULONG_MAX, 0);
+}
+#else
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
+static inline void cpufreq_trigger_update(u64 time) {}
+#endif /* CONFIG_CPU_FREQ */
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index b0fbc7632de5..70b3b6a20fb0 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -29,9 +29,10 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.run_delay += delta;
}
-# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
-# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
-# define schedstat_set(var, val) do { var = (val); } while (0)
+# define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
+# define schedstat_inc(rq, field) do { if (schedstat_enabled()) { (rq)->field++; } } while (0)
+# define schedstat_add(rq, field, amt) do { if (schedstat_enabled()) { (rq)->field += (amt); } } while (0)
+# define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
#else /* !CONFIG_SCHEDSTATS */
static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
@@ -42,6 +43,7 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{}
+# define schedstat_enabled() 0
# define schedstat_inc(rq, field) do { } while (0)
# define schedstat_add(rq, field, amt) do { } while (0)
# define schedstat_set(var, val) do { } while (0)
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
new file mode 100644
index 000000000000..82f0dff90030
--- /dev/null
+++ b/kernel/sched/swait.c
@@ -0,0 +1,123 @@
+#include <linux/sched.h>
+#include <linux/swait.h>
+
+void __init_swait_queue_head(struct swait_queue_head *q, const char *name,
+ struct lock_class_key *key)
+{
+ raw_spin_lock_init(&q->lock);
+ lockdep_set_class_and_name(&q->lock, key, name);
+ INIT_LIST_HEAD(&q->task_list);
+}
+EXPORT_SYMBOL(__init_swait_queue_head);
+
+/*
+ * The thing about the wake_up_state() return value; I think we can ignore it.
+ *
+ * If for some reason it would return 0, that means the previously waiting
+ * task is already running, so it will observe condition true (or has already).
+ */
+void swake_up_locked(struct swait_queue_head *q)
+{
+ struct swait_queue *curr;
+
+ if (list_empty(&q->task_list))
+ return;
+
+ curr = list_first_entry(&q->task_list, typeof(*curr), task_list);
+ wake_up_process(curr->task);
+ list_del_init(&curr->task_list);
+}
+EXPORT_SYMBOL(swake_up_locked);
+
+void swake_up(struct swait_queue_head *q)
+{
+ unsigned long flags;
+
+ if (!swait_active(q))
+ return;
+
+ raw_spin_lock_irqsave(&q->lock, flags);
+ swake_up_locked(q);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(swake_up);
+
+/*
+ * Does not allow usage from IRQ disabled, since we must be able to
+ * release IRQs to guarantee bounded hold time.
+ */
+void swake_up_all(struct swait_queue_head *q)
+{
+ struct swait_queue *curr;
+ LIST_HEAD(tmp);
+
+ if (!swait_active(q))
+ return;
+
+ raw_spin_lock_irq(&q->lock);
+ list_splice_init(&q->task_list, &tmp);
+ while (!list_empty(&tmp)) {
+ curr = list_first_entry(&tmp, typeof(*curr), task_list);
+
+ wake_up_state(curr->task, TASK_NORMAL);
+ list_del_init(&curr->task_list);
+
+ if (list_empty(&tmp))
+ break;
+
+ raw_spin_unlock_irq(&q->lock);
+ raw_spin_lock_irq(&q->lock);
+ }
+ raw_spin_unlock_irq(&q->lock);
+}
+EXPORT_SYMBOL(swake_up_all);
+
+void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ wait->task = current;
+ if (list_empty(&wait->task_list))
+ list_add(&wait->task_list, &q->task_list);
+}
+
+void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&q->lock, flags);
+ __prepare_to_swait(q, wait);
+ set_current_state(state);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(prepare_to_swait);
+
+long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state)
+{
+ if (signal_pending_state(state, current))
+ return -ERESTARTSYS;
+
+ prepare_to_swait(q, wait, state);
+
+ return 0;
+}
+EXPORT_SYMBOL(prepare_to_swait_event);
+
+void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ __set_current_state(TASK_RUNNING);
+ if (!list_empty(&wait->task_list))
+ list_del_init(&wait->task_list);
+}
+
+void finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ unsigned long flags;
+
+ __set_current_state(TASK_RUNNING);
+
+ if (!list_empty_careful(&wait->task_list)) {
+ raw_spin_lock_irqsave(&q->lock, flags);
+ list_del_init(&wait->task_list);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+ }
+}
+EXPORT_SYMBOL(finish_swait);
diff --git a/kernel/smp.c b/kernel/smp.c
index d903c02223af..74165443c240 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -105,13 +105,12 @@ void __init call_function_init(void)
* previous function call. For multi-cpu calls its even more interesting
* as we'll have to ensure no other cpu is observing our csd.
*/
-static void csd_lock_wait(struct call_single_data *csd)
+static __always_inline void csd_lock_wait(struct call_single_data *csd)
{
- while (smp_load_acquire(&csd->flags) & CSD_FLAG_LOCK)
- cpu_relax();
+ smp_cond_acquire(!(csd->flags & CSD_FLAG_LOCK));
}
-static void csd_lock(struct call_single_data *csd)
+static __always_inline void csd_lock(struct call_single_data *csd)
{
csd_lock_wait(csd);
csd->flags |= CSD_FLAG_LOCK;
@@ -124,7 +123,7 @@ static void csd_lock(struct call_single_data *csd)
smp_wmb();
}
-static void csd_unlock(struct call_single_data *csd)
+static __always_inline void csd_unlock(struct call_single_data *csd)
{
WARN_ON(!(csd->flags & CSD_FLAG_LOCK));
@@ -569,6 +568,7 @@ void __init smp_init(void)
unsigned int cpu;
idle_threads_init();
+ cpuhp_threads_init();
/* FIXME: This should be done in userspace --RR */
for_each_present_cpu(cpu) {
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index d264f59bff56..13bc43d1fb22 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -226,7 +226,7 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp
kthread_unpark(tsk);
}
-void smpboot_unpark_threads(unsigned int cpu)
+int smpboot_unpark_threads(unsigned int cpu)
{
struct smp_hotplug_thread *cur;
@@ -235,6 +235,7 @@ void smpboot_unpark_threads(unsigned int cpu)
if (cpumask_test_cpu(cpu, cur->cpumask))
smpboot_unpark_thread(cur, cpu);
mutex_unlock(&smpboot_threads_lock);
+ return 0;
}
static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
@@ -245,7 +246,7 @@ static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
kthread_park(tsk);
}
-void smpboot_park_threads(unsigned int cpu)
+int smpboot_park_threads(unsigned int cpu)
{
struct smp_hotplug_thread *cur;
@@ -253,6 +254,7 @@ void smpboot_park_threads(unsigned int cpu)
list_for_each_entry_reverse(cur, &hotplug_threads, list)
smpboot_park_thread(cur, cpu);
mutex_unlock(&smpboot_threads_lock);
+ return 0;
}
static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 72415a0eb955..485b81cfab34 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -14,7 +14,9 @@ static inline void idle_threads_init(void) { }
#endif
int smpboot_create_threads(unsigned int cpu);
-void smpboot_park_threads(unsigned int cpu);
-void smpboot_unpark_threads(unsigned int cpu);
+int smpboot_park_threads(unsigned int cpu);
+int smpboot_unpark_threads(unsigned int cpu);
+
+void __init cpuhp_threads_init(void);
#endif
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 479e4436f787..8aae49dd7da8 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -116,9 +116,9 @@ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
if (preempt_count() == cnt) {
#ifdef CONFIG_DEBUG_PREEMPT
- current->preempt_disable_ip = get_parent_ip(CALLER_ADDR1);
+ current->preempt_disable_ip = get_lock_parent_ip();
#endif
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip());
}
}
EXPORT_SYMBOL(__local_bh_disable_ip);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 97715fd9e790..f5102fabef7f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -350,6 +350,17 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+#ifdef CONFIG_SCHEDSTATS
+ {
+ .procname = "sched_schedstats",
+ .data = NULL,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = sysctl_schedstats,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+#endif /* CONFIG_SCHEDSTATS */
#endif /* CONFIG_SMP */
#ifdef CONFIG_NUMA_BALANCING
{
@@ -505,7 +516,7 @@ static struct ctl_table kern_table[] = {
.data = &latencytop_enabled,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = sysctl_latencytop,
},
#endif
#ifdef CONFIG_BLK_DEV_INITRD
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 664de539299b..56ece145a814 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -323,13 +323,42 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
/* cs is a watchdog. */
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+ }
+ spin_unlock_irqrestore(&watchdog_lock, flags);
+}
+
+static void clocksource_select_watchdog(bool fallback)
+{
+ struct clocksource *cs, *old_wd;
+ unsigned long flags;
+
+ spin_lock_irqsave(&watchdog_lock, flags);
+ /* save current watchdog */
+ old_wd = watchdog;
+ if (fallback)
+ watchdog = NULL;
+
+ list_for_each_entry(cs, &clocksource_list, list) {
+ /* cs is a clocksource to be watched. */
+ if (cs->flags & CLOCK_SOURCE_MUST_VERIFY)
+ continue;
+
+ /* Skip current if we were requested for a fallback. */
+ if (fallback && cs == old_wd)
+ continue;
+
/* Pick the best watchdog. */
- if (!watchdog || cs->rating > watchdog->rating) {
+ if (!watchdog || cs->rating > watchdog->rating)
watchdog = cs;
- /* Reset watchdog cycles */
- clocksource_reset_watchdog();
- }
}
+ /* If we failed to find a fallback restore the old one. */
+ if (!watchdog)
+ watchdog = old_wd;
+
+ /* If we changed the watchdog we need to reset cycles. */
+ if (watchdog != old_wd)
+ clocksource_reset_watchdog();
+
/* Check if the watchdog timer needs to be started. */
clocksource_start_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
@@ -404,6 +433,7 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
}
+static void clocksource_select_watchdog(bool fallback) { }
static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
static inline void clocksource_resume_watchdog(void) { }
static inline int __clocksource_watchdog_kthread(void) { return 0; }
@@ -736,6 +766,7 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
clocksource_enqueue(cs);
clocksource_enqueue_watchdog(cs);
clocksource_select();
+ clocksource_select_watchdog(false);
mutex_unlock(&clocksource_mutex);
return 0;
}
@@ -758,6 +789,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
mutex_lock(&clocksource_mutex);
__clocksource_change_rating(cs, rating);
clocksource_select();
+ clocksource_select_watchdog(false);
mutex_unlock(&clocksource_mutex);
}
EXPORT_SYMBOL(clocksource_change_rating);
@@ -767,12 +799,12 @@ EXPORT_SYMBOL(clocksource_change_rating);
*/
static int clocksource_unbind(struct clocksource *cs)
{
- /*
- * I really can't convince myself to support this on hardware
- * designed by lobotomized monkeys.
- */
- if (clocksource_is_watchdog(cs))
- return -EBUSY;
+ if (clocksource_is_watchdog(cs)) {
+ /* Select and try to install a replacement watchdog. */
+ clocksource_select_watchdog(true);
+ if (clocksource_is_watchdog(cs))
+ return -EBUSY;
+ }
if (cs == curr_clocksource) {
/* Select and try to install a replacement clock source */
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 347fecf86a3f..555e21f7b966 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -68,7 +68,7 @@ static struct clocksource clocksource_jiffies = {
.name = "jiffies",
.rating = 1, /* lowest valid rating*/
.read = jiffies_read,
- .mask = 0xffffffff, /*32bits*/
+ .mask = CLOCKSOURCE_MASK(32),
.mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
.shift = JIFFIES_SHIFT,
.max_cycles = 10,
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index f5e86d282d52..1cafba860b08 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -333,7 +333,6 @@ static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
return err;
}
-
/*
* Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
* This is called from sys_timer_create() and do_cpu_nanosleep() with the
@@ -517,6 +516,10 @@ static void arm_timer(struct k_itimer *timer)
cputime_expires->sched_exp = exp;
break;
}
+ if (CPUCLOCK_PERTHREAD(timer->it_clock))
+ tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
+ else
+ tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
}
}
@@ -582,39 +585,6 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
return 0;
}
-#ifdef CONFIG_NO_HZ_FULL
-static void nohz_kick_work_fn(struct work_struct *work)
-{
- tick_nohz_full_kick_all();
-}
-
-static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);
-
-/*
- * We need the IPIs to be sent from sane process context.
- * The posix cpu timers are always set with irqs disabled.
- */
-static void posix_cpu_timer_kick_nohz(void)
-{
- if (context_tracking_is_enabled())
- schedule_work(&nohz_kick_work);
-}
-
-bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
-{
- if (!task_cputime_zero(&tsk->cputime_expires))
- return false;
-
- /* Check if cputimer is running. This is accessed without locking. */
- if (READ_ONCE(tsk->signal->cputimer.running))
- return false;
-
- return true;
-}
-#else
-static inline void posix_cpu_timer_kick_nohz(void) { }
-#endif
-
/*
* Guts of sys_timer_settime for CPU timers.
* This is called with the timer locked and interrupts disabled.
@@ -761,8 +731,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
sample_to_timespec(timer->it_clock,
old_incr, &old->it_interval);
}
- if (!ret)
- posix_cpu_timer_kick_nohz();
+
return ret;
}
@@ -911,6 +880,8 @@ static void check_thread_timers(struct task_struct *tsk,
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
}
}
+ if (task_cputime_zero(tsk_expires))
+ tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
}
static inline void stop_process_timers(struct signal_struct *sig)
@@ -919,6 +890,7 @@ static inline void stop_process_timers(struct signal_struct *sig)
/* Turn off cputimer->running. This is done without locking. */
WRITE_ONCE(cputimer->running, false);
+ tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
}
static u32 onecputick;
@@ -1095,8 +1067,6 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
arm_timer(timer);
unlock_task_sighand(p, &flags);
- /* Kick full dynticks CPUs in case they need to tick on the new timer */
- posix_cpu_timer_kick_nohz();
out:
timer->it_overrun_last = timer->it_overrun;
timer->it_overrun = -1;
@@ -1270,7 +1240,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
}
if (!*newval)
- goto out;
+ return;
*newval += now;
}
@@ -1288,8 +1258,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
tsk->signal->cputime_expires.virt_exp = *newval;
break;
}
-out:
- posix_cpu_timer_kick_nohz();
+
+ tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
}
static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 0b17424349eb..969e6704c3c9 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -22,7 +22,6 @@
#include <linux/module.h>
#include <linux/irq_work.h>
#include <linux/posix-timers.h>
-#include <linux/perf_event.h>
#include <linux/context_tracking.h>
#include <asm/irq_regs.h>
@@ -158,54 +157,63 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
cpumask_var_t tick_nohz_full_mask;
cpumask_var_t housekeeping_mask;
bool tick_nohz_full_running;
+static unsigned long tick_dep_mask;
-static bool can_stop_full_tick(void)
+static void trace_tick_dependency(unsigned long dep)
+{
+ if (dep & TICK_DEP_MASK_POSIX_TIMER) {
+ trace_tick_stop(0, TICK_DEP_MASK_POSIX_TIMER);
+ return;
+ }
+
+ if (dep & TICK_DEP_MASK_PERF_EVENTS) {
+ trace_tick_stop(0, TICK_DEP_MASK_PERF_EVENTS);
+ return;
+ }
+
+ if (dep & TICK_DEP_MASK_SCHED) {
+ trace_tick_stop(0, TICK_DEP_MASK_SCHED);
+ return;
+ }
+
+ if (dep & TICK_DEP_MASK_CLOCK_UNSTABLE)
+ trace_tick_stop(0, TICK_DEP_MASK_CLOCK_UNSTABLE);
+}
+
+static bool can_stop_full_tick(struct tick_sched *ts)
{
WARN_ON_ONCE(!irqs_disabled());
- if (!sched_can_stop_tick()) {
- trace_tick_stop(0, "more than 1 task in runqueue\n");
+ if (tick_dep_mask) {
+ trace_tick_dependency(tick_dep_mask);
return false;
}
- if (!posix_cpu_timers_can_stop_tick(current)) {
- trace_tick_stop(0, "posix timers running\n");
+ if (ts->tick_dep_mask) {
+ trace_tick_dependency(ts->tick_dep_mask);
return false;
}
- if (!perf_event_can_stop_tick()) {
- trace_tick_stop(0, "perf events running\n");
+ if (current->tick_dep_mask) {
+ trace_tick_dependency(current->tick_dep_mask);
return false;
}
- /* sched_clock_tick() needs us? */
-#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
- /*
- * TODO: kick full dynticks CPUs when
- * sched_clock_stable is set.
- */
- if (!sched_clock_stable()) {
- trace_tick_stop(0, "unstable sched clock\n");
- /*
- * Don't allow the user to think they can get
- * full NO_HZ with this machine.
- */
- WARN_ONCE(tick_nohz_full_running,
- "NO_HZ FULL will not work with unstable sched clock");
+ if (current->signal->tick_dep_mask) {
+ trace_tick_dependency(current->signal->tick_dep_mask);
return false;
}
-#endif
return true;
}
-static void nohz_full_kick_work_func(struct irq_work *work)
+static void nohz_full_kick_func(struct irq_work *work)
{
/* Empty, the tick restart happens on tick_nohz_irq_exit() */
}
static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
- .func = nohz_full_kick_work_func,
+ .func = nohz_full_kick_func,
};
/*
@@ -214,7 +222,7 @@ static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
* This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(),
* is NMI safe.
*/
-void tick_nohz_full_kick(void)
+static void tick_nohz_full_kick(void)
{
if (!tick_nohz_full_cpu(smp_processor_id()))
return;
@@ -234,27 +242,112 @@ void tick_nohz_full_kick_cpu(int cpu)
irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu);
}
-static void nohz_full_kick_ipi(void *info)
-{
- /* Empty, the tick restart happens on tick_nohz_irq_exit() */
-}
-
/*
* Kick all full dynticks CPUs in order to force these to re-evaluate
* their dependency on the tick and restart it if necessary.
*/
-void tick_nohz_full_kick_all(void)
+static void tick_nohz_full_kick_all(void)
{
+ int cpu;
+
if (!tick_nohz_full_running)
return;
preempt_disable();
- smp_call_function_many(tick_nohz_full_mask,
- nohz_full_kick_ipi, NULL, false);
- tick_nohz_full_kick();
+ for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask)
+ tick_nohz_full_kick_cpu(cpu);
preempt_enable();
}
+static void tick_nohz_dep_set_all(unsigned long *dep,
+ enum tick_dep_bits bit)
+{
+ unsigned long prev;
+
+ prev = fetch_or(dep, BIT_MASK(bit));
+ if (!prev)
+ tick_nohz_full_kick_all();
+}
+
+/*
+ * Set a global tick dependency. Used by perf events that rely on freq and
+ * by unstable clock.
+ */
+void tick_nohz_dep_set(enum tick_dep_bits bit)
+{
+ tick_nohz_dep_set_all(&tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear(enum tick_dep_bits bit)
+{
+ clear_bit(bit, &tick_dep_mask);
+}
+
+/*
+ * Set per-CPU tick dependency. Used by scheduler and perf events in order to
+ * manage events throttling.
+ */
+void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit)
+{
+ unsigned long prev;
+ struct tick_sched *ts;
+
+ ts = per_cpu_ptr(&tick_cpu_sched, cpu);
+
+ prev = fetch_or(&ts->tick_dep_mask, BIT_MASK(bit));
+ if (!prev) {
+ preempt_disable();
+ /* Perf needs local kick that is NMI safe */
+ if (cpu == smp_processor_id()) {
+ tick_nohz_full_kick();
+ } else {
+ /* Remote irq work not NMI-safe */
+ if (!WARN_ON_ONCE(in_nmi()))
+ tick_nohz_full_kick_cpu(cpu);
+ }
+ preempt_enable();
+ }
+}
+
+void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
+{
+ struct tick_sched *ts = per_cpu_ptr(&tick_cpu_sched, cpu);
+
+ clear_bit(bit, &ts->tick_dep_mask);
+}
+
+/*
+ * Set a per-task tick dependency. Posix CPU timers need this in order to elapse
+ * per task timers.
+ */
+void tick_nohz_dep_set_task(struct task_struct *tsk, enum tick_dep_bits bit)
+{
+ /*
+ * We could optimize this with just kicking the target running the task
+ * if that noise matters for nohz full users.
+ */
+ tick_nohz_dep_set_all(&tsk->tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear_task(struct task_struct *tsk, enum tick_dep_bits bit)
+{
+ clear_bit(bit, &tsk->tick_dep_mask);
+}
+
+/*
+ * Set a per-taskgroup tick dependency. Posix CPU timers need this in order to elapse
+ * per process timers.
+ */
+void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits bit)
+{
+ tick_nohz_dep_set_all(&sig->tick_dep_mask, bit);
+}
+
+void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bit)
+{
+ clear_bit(bit, &sig->tick_dep_mask);
+}
+
/*
* Re-evaluate the need for the tick as we switch the current task.
* It might need the tick due to per task/process properties:
@@ -263,15 +356,19 @@ void tick_nohz_full_kick_all(void)
void __tick_nohz_task_switch(void)
{
unsigned long flags;
+ struct tick_sched *ts;
local_irq_save(flags);
if (!tick_nohz_full_cpu(smp_processor_id()))
goto out;
- if (tick_nohz_tick_stopped() && !can_stop_full_tick())
- tick_nohz_full_kick();
+ ts = this_cpu_ptr(&tick_cpu_sched);
+ if (ts->tick_stopped) {
+ if (current->tick_dep_mask || current->signal->tick_dep_mask)
+ tick_nohz_full_kick();
+ }
out:
local_irq_restore(flags);
}
@@ -689,7 +786,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
ts->tick_stopped = 1;
- trace_tick_stop(1, " ");
+ trace_tick_stop(1, TICK_DEP_MASK_NONE);
}
/*
@@ -740,7 +837,7 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts)
if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
return;
- if (can_stop_full_tick())
+ if (can_stop_full_tick(ts))
tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
else if (ts->tick_stopped)
tick_nohz_restart_sched_tick(ts, ktime_get(), 1);
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
index a4a8d4e9baa1..eb4e32566a83 100644
--- a/kernel/time/tick-sched.h
+++ b/kernel/time/tick-sched.h
@@ -60,6 +60,7 @@ struct tick_sched {
u64 next_timer;
ktime_t idle_expires;
int do_timer_last;
+ unsigned long tick_dep_mask;
};
extern struct tick_sched *tick_get_tick_sched(int cpu);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 34b4cedfa80d..9c629bbed572 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -233,6 +233,7 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
u64 tmp, ntpinterval;
struct clocksource *old_clock;
+ ++tk->cs_was_changed_seq;
old_clock = tk->tkr_mono.clock;
tk->tkr_mono.clock = clock;
tk->tkr_mono.read = clock->read;
@@ -298,17 +299,34 @@ u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
static inline u32 arch_gettimeoffset(void) { return 0; }
#endif
+static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
+ cycle_t delta)
+{
+ s64 nsec;
+
+ nsec = delta * tkr->mult + tkr->xtime_nsec;
+ nsec >>= tkr->shift;
+
+ /* If arch requires, add in get_arch_timeoffset() */
+ return nsec + arch_gettimeoffset();
+}
+
static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
{
cycle_t delta;
- s64 nsec;
delta = timekeeping_get_delta(tkr);
+ return timekeeping_delta_to_ns(tkr, delta);
+}
- nsec = (delta * tkr->mult + tkr->xtime_nsec) >> tkr->shift;
+static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
+ cycle_t cycles)
+{
+ cycle_t delta;
- /* If arch requires, add in get_arch_timeoffset() */
- return nsec + arch_gettimeoffset();
+ /* calculate the delta since the last update_wall_time */
+ delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask);
+ return timekeeping_delta_to_ns(tkr, delta);
}
/**
@@ -857,44 +875,262 @@ time64_t __ktime_get_real_seconds(void)
return tk->xtime_sec;
}
+/**
+ * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter
+ * @systime_snapshot: pointer to struct receiving the system time snapshot
+ */
+void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ unsigned long seq;
+ ktime_t base_raw;
+ ktime_t base_real;
+ s64 nsec_raw;
+ s64 nsec_real;
+ cycle_t now;
-#ifdef CONFIG_NTP_PPS
+ WARN_ON_ONCE(timekeeping_suspended);
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+
+ now = tk->tkr_mono.read(tk->tkr_mono.clock);
+ systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq;
+ systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq;
+ base_real = ktime_add(tk->tkr_mono.base,
+ tk_core.timekeeper.offs_real);
+ base_raw = tk->tkr_raw.base;
+ nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now);
+ nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ systime_snapshot->cycles = now;
+ systime_snapshot->real = ktime_add_ns(base_real, nsec_real);
+ systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);
+}
+EXPORT_SYMBOL_GPL(ktime_get_snapshot);
+
+/* Scale base by mult/div checking for overflow */
+static int scale64_check_overflow(u64 mult, u64 div, u64 *base)
+{
+ u64 tmp, rem;
+
+ tmp = div64_u64_rem(*base, div, &rem);
+
+ if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) ||
+ ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem)))
+ return -EOVERFLOW;
+ tmp *= mult;
+ rem *= mult;
+
+ do_div(rem, div);
+ *base = tmp + rem;
+ return 0;
+}
/**
- * ktime_get_raw_and_real_ts64 - get day and raw monotonic time in timespec format
- * @ts_raw: pointer to the timespec to be set to raw monotonic time
- * @ts_real: pointer to the timespec to be set to the time of day
+ * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval
+ * @history: Snapshot representing start of history
+ * @partial_history_cycles: Cycle offset into history (fractional part)
+ * @total_history_cycles: Total history length in cycles
+ * @discontinuity: True indicates clock was set on history period
+ * @ts: Cross timestamp that should be adjusted using
+ * partial/total ratio
*
- * This function reads both the time of day and raw monotonic time at the
- * same time atomically and stores the resulting timestamps in timespec
- * format.
+ * Helper function used by get_device_system_crosststamp() to correct the
+ * crosstimestamp corresponding to the start of the current interval to the
+ * system counter value (timestamp point) provided by the driver. The
+ * total_history_* quantities are the total history starting at the provided
+ * reference point and ending at the start of the current interval. The cycle
+ * count between the driver timestamp point and the start of the current
+ * interval is partial_history_cycles.
*/
-void ktime_get_raw_and_real_ts64(struct timespec64 *ts_raw, struct timespec64 *ts_real)
+static int adjust_historical_crosststamp(struct system_time_snapshot *history,
+ cycle_t partial_history_cycles,
+ cycle_t total_history_cycles,
+ bool discontinuity,
+ struct system_device_crosststamp *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
- unsigned long seq;
- s64 nsecs_raw, nsecs_real;
+ u64 corr_raw, corr_real;
+ bool interp_forward;
+ int ret;
- WARN_ON_ONCE(timekeeping_suspended);
+ if (total_history_cycles == 0 || partial_history_cycles == 0)
+ return 0;
+
+ /* Interpolate shortest distance from beginning or end of history */
+ interp_forward = partial_history_cycles > total_history_cycles/2 ?
+ true : false;
+ partial_history_cycles = interp_forward ?
+ total_history_cycles - partial_history_cycles :
+ partial_history_cycles;
+
+ /*
+ * Scale the monotonic raw time delta by:
+ * partial_history_cycles / total_history_cycles
+ */
+ corr_raw = (u64)ktime_to_ns(
+ ktime_sub(ts->sys_monoraw, history->raw));
+ ret = scale64_check_overflow(partial_history_cycles,
+ total_history_cycles, &corr_raw);
+ if (ret)
+ return ret;
+
+ /*
+ * If there is a discontinuity in the history, scale monotonic raw
+ * correction by:
+ * mult(real)/mult(raw) yielding the realtime correction
+ * Otherwise, calculate the realtime correction similar to monotonic
+ * raw calculation
+ */
+ if (discontinuity) {
+ corr_real = mul_u64_u32_div
+ (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult);
+ } else {
+ corr_real = (u64)ktime_to_ns(
+ ktime_sub(ts->sys_realtime, history->real));
+ ret = scale64_check_overflow(partial_history_cycles,
+ total_history_cycles, &corr_real);
+ if (ret)
+ return ret;
+ }
+
+ /* Fixup monotonic raw and real time time values */
+ if (interp_forward) {
+ ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw);
+ ts->sys_realtime = ktime_add_ns(history->real, corr_real);
+ } else {
+ ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw);
+ ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real);
+ }
+
+ return 0;
+}
+
+/*
+ * cycle_between - true if test occurs chronologically between before and after
+ */
+static bool cycle_between(cycle_t before, cycle_t test, cycle_t after)
+{
+ if (test > before && test < after)
+ return true;
+ if (test < before && before > after)
+ return true;
+ return false;
+}
+
+/**
+ * get_device_system_crosststamp - Synchronously capture system/device timestamp
+ * @get_time_fn: Callback to get simultaneous device time and
+ * system counter from the device driver
+ * @ctx: Context passed to get_time_fn()
+ * @history_begin: Historical reference point used to interpolate system
+ * time when counter provided by the driver is before the current interval
+ * @xtstamp: Receives simultaneously captured system and device time
+ *
+ * Reads a timestamp from a device and correlates it to system time
+ */
+int get_device_system_crosststamp(int (*get_time_fn)
+ (ktime_t *device_time,
+ struct system_counterval_t *sys_counterval,
+ void *ctx),
+ void *ctx,
+ struct system_time_snapshot *history_begin,
+ struct system_device_crosststamp *xtstamp)
+{
+ struct system_counterval_t system_counterval;
+ struct timekeeper *tk = &tk_core.timekeeper;
+ cycle_t cycles, now, interval_start;
+ unsigned int clock_was_set_seq = 0;
+ ktime_t base_real, base_raw;
+ s64 nsec_real, nsec_raw;
+ u8 cs_was_changed_seq;
+ unsigned long seq;
+ bool do_interp;
+ int ret;
do {
seq = read_seqcount_begin(&tk_core.seq);
+ /*
+ * Try to synchronously capture device time and a system
+ * counter value calling back into the device driver
+ */
+ ret = get_time_fn(&xtstamp->device, &system_counterval, ctx);
+ if (ret)
+ return ret;
+
+ /*
+ * Verify that the clocksource associated with the captured
+ * system counter value is the same as the currently installed
+ * timekeeper clocksource
+ */
+ if (tk->tkr_mono.clock != system_counterval.cs)
+ return -ENODEV;
+ cycles = system_counterval.cycles;
- *ts_raw = tk->raw_time;
- ts_real->tv_sec = tk->xtime_sec;
- ts_real->tv_nsec = 0;
+ /*
+ * Check whether the system counter value provided by the
+ * device driver is on the current timekeeping interval.
+ */
+ now = tk->tkr_mono.read(tk->tkr_mono.clock);
+ interval_start = tk->tkr_mono.cycle_last;
+ if (!cycle_between(interval_start, cycles, now)) {
+ clock_was_set_seq = tk->clock_was_set_seq;
+ cs_was_changed_seq = tk->cs_was_changed_seq;
+ cycles = interval_start;
+ do_interp = true;
+ } else {
+ do_interp = false;
+ }
- nsecs_raw = timekeeping_get_ns(&tk->tkr_raw);
- nsecs_real = timekeeping_get_ns(&tk->tkr_mono);
+ base_real = ktime_add(tk->tkr_mono.base,
+ tk_core.timekeeper.offs_real);
+ base_raw = tk->tkr_raw.base;
+ nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono,
+ system_counterval.cycles);
+ nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw,
+ system_counterval.cycles);
} while (read_seqcount_retry(&tk_core.seq, seq));
- timespec64_add_ns(ts_raw, nsecs_raw);
- timespec64_add_ns(ts_real, nsecs_real);
-}
-EXPORT_SYMBOL(ktime_get_raw_and_real_ts64);
+ xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real);
+ xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw);
-#endif /* CONFIG_NTP_PPS */
+ /*
+ * Interpolate if necessary, adjusting back from the start of the
+ * current interval
+ */
+ if (do_interp) {
+ cycle_t partial_history_cycles, total_history_cycles;
+ bool discontinuity;
+
+ /*
+ * Check that the counter value occurs after the provided
+ * history reference and that the history doesn't cross a
+ * clocksource change
+ */
+ if (!history_begin ||
+ !cycle_between(history_begin->cycles,
+ system_counterval.cycles, cycles) ||
+ history_begin->cs_was_changed_seq != cs_was_changed_seq)
+ return -EINVAL;
+ partial_history_cycles = cycles - system_counterval.cycles;
+ total_history_cycles = cycles - history_begin->cycles;
+ discontinuity =
+ history_begin->clock_was_set_seq != clock_was_set_seq;
+
+ ret = adjust_historical_crosststamp(history_begin,
+ partial_history_cycles,
+ total_history_cycles,
+ discontinuity, xtstamp);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(get_device_system_crosststamp);
/**
* do_gettimeofday - Returns the time of day in a timeval
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca592f977b2..57a6eea84694 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4961,7 +4961,7 @@ void ftrace_release_mod(struct module *mod)
mutex_unlock(&ftrace_lock);
}
-static void ftrace_module_enable(struct module *mod)
+void ftrace_module_enable(struct module *mod)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
@@ -5038,38 +5038,8 @@ void ftrace_module_init(struct module *mod)
ftrace_process_locs(mod, mod->ftrace_callsites,
mod->ftrace_callsites + mod->num_ftrace_callsites);
}
-
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- struct module *mod = data;
-
- switch (val) {
- case MODULE_STATE_COMING:
- ftrace_module_enable(mod);
- break;
- case MODULE_STATE_GOING:
- ftrace_release_mod(mod);
- break;
- default:
- break;
- }
-
- return 0;
-}
-#else
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- return 0;
-}
#endif /* CONFIG_MODULES */
-struct notifier_block ftrace_module_nb = {
- .notifier_call = ftrace_module_notify,
- .priority = INT_MIN, /* Run after anything that can remove kprobes */
-};
-
void __init ftrace_init(void)
{
extern unsigned long __start_mcount_loc[];
@@ -5098,10 +5068,6 @@ void __init ftrace_init(void)
__start_mcount_loc,
__stop_mcount_loc);
- ret = register_module_notifier(&ftrace_module_nb);
- if (ret)
- pr_warning("Failed to register trace ftrace module exit notifier\n");
-
set_ftrace_early_filters();
return;
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
index eb4220a132ec..81b87451c0ea 100644
--- a/kernel/trace/power-traces.c
+++ b/kernel/trace/power-traces.c
@@ -15,4 +15,5 @@
EXPORT_TRACEPOINT_SYMBOL_GPL(suspend_resume);
EXPORT_TRACEPOINT_SYMBOL_GPL(cpu_idle);
+EXPORT_TRACEPOINT_SYMBOL_GPL(powernv_throttle);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f333e57c4614..05ddc0820771 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -97,16 +97,16 @@ trace_find_event_field(struct trace_event_call *call, char *name)
struct ftrace_event_field *field;
struct list_head *head;
- field = __find_event_field(&ftrace_generic_fields, name);
+ head = trace_get_fields(call);
+ field = __find_event_field(head, name);
if (field)
return field;
- field = __find_event_field(&ftrace_common_fields, name);
+ field = __find_event_field(&ftrace_generic_fields, name);
if (field)
return field;
- head = trace_get_fields(call);
- return __find_event_field(head, name);
+ return __find_event_field(&ftrace_common_fields, name);
}
static int __trace_define_field(struct list_head *head, const char *type,
@@ -171,8 +171,10 @@ static int trace_define_generic_fields(void)
{
int ret;
- __generic_field(int, cpu, FILTER_OTHER);
- __generic_field(char *, comm, FILTER_PTR_STRING);
+ __generic_field(int, CPU, FILTER_CPU);
+ __generic_field(int, cpu, FILTER_CPU);
+ __generic_field(char *, COMM, FILTER_COMM);
+ __generic_field(char *, comm, FILTER_COMM);
return ret;
}
@@ -869,7 +871,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
* The ftrace subsystem is for showing formats only.
* They can not be enabled or disabled via the event files.
*/
- if (call->class && call->class->reg)
+ if (call->class && call->class->reg &&
+ !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
return file;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f93a219b18da..6816302542b2 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1043,13 +1043,14 @@ static int init_pred(struct filter_parse_state *ps,
return -EINVAL;
}
- if (is_string_field(field)) {
+ if (field->filter_type == FILTER_COMM) {
+ filter_build_regex(pred);
+ fn = filter_pred_comm;
+ pred->regex.field_len = TASK_COMM_LEN;
+ } else if (is_string_field(field)) {
filter_build_regex(pred);
- if (!strcmp(field->name, "comm")) {
- fn = filter_pred_comm;
- pred->regex.field_len = TASK_COMM_LEN;
- } else if (field->filter_type == FILTER_STATIC_STRING) {
+ if (field->filter_type == FILTER_STATIC_STRING) {
fn = filter_pred_string;
pred->regex.field_len = field->size;
} else if (field->filter_type == FILTER_DYN_STRING)
@@ -1072,7 +1073,7 @@ static int init_pred(struct filter_parse_state *ps,
}
pred->val = val;
- if (!strcmp(field->name, "cpu"))
+ if (field->filter_type == FILTER_CPU)
fn = filter_pred_cpu;
else
fn = select_comparison_fn(pred->op, field->size,
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c9956440d0e6..21b81a41dae5 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -30,7 +30,7 @@
struct trace_kprobe {
struct list_head list;
struct kretprobe rp; /* Use rp.kp for kprobe use */
- unsigned long nhit;
+ unsigned long __percpu *nhit;
const char *symbol; /* symbol name */
struct trace_probe tp;
};
@@ -274,6 +274,10 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
if (!tk)
return ERR_PTR(ret);
+ tk->nhit = alloc_percpu(unsigned long);
+ if (!tk->nhit)
+ goto error;
+
if (symbol) {
tk->symbol = kstrdup(symbol, GFP_KERNEL);
if (!tk->symbol)
@@ -313,6 +317,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
error:
kfree(tk->tp.call.name);
kfree(tk->symbol);
+ free_percpu(tk->nhit);
kfree(tk);
return ERR_PTR(ret);
}
@@ -327,6 +332,7 @@ static void free_trace_kprobe(struct trace_kprobe *tk)
kfree(tk->tp.call.class->system);
kfree(tk->tp.call.name);
kfree(tk->symbol);
+ free_percpu(tk->nhit);
kfree(tk);
}
@@ -874,9 +880,14 @@ static const struct file_operations kprobe_events_ops = {
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct trace_kprobe *tk = v;
+ unsigned long nhit = 0;
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ nhit += *per_cpu_ptr(tk->nhit, cpu);
seq_printf(m, " %-44s %15lu %15lu\n",
- trace_event_name(&tk->tp.call), tk->nhit,
+ trace_event_name(&tk->tp.call), nhit,
tk->rp.kp.nmissed);
return 0;
@@ -1225,7 +1236,7 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
{
struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
- tk->nhit++;
+ raw_cpu_inc(*tk->nhit);
if (tk->tp.flags & TP_FLAG_TRACE)
kprobe_trace_func(tk, regs);
@@ -1242,7 +1253,7 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
{
struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
- tk->nhit++;
+ raw_cpu_inc(*tk->nhit);
if (tk->tp.flags & TP_FLAG_TRACE)
kretprobe_trace_func(tk, ri, regs);
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 202df6cffcca..2a1abbaca10e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -156,7 +156,11 @@ check_stack(unsigned long ip, unsigned long *stack)
for (; p < top && i < stack_trace_max.nr_entries; p++) {
if (stack_dump_trace[i] == ULONG_MAX)
break;
- if (*p == stack_dump_trace[i]) {
+ /*
+ * The READ_ONCE_NOCHECK is used to let KASAN know that
+ * this is not a stack-out-of-bounds error.
+ */
+ if ((READ_ONCE_NOCHECK(*p)) == stack_dump_trace[i]) {
stack_dump_trace[x] = stack_dump_trace[i++];
this_size = stack_trace_index[x++] =
(top - p) * sizeof(unsigned long);
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 0655afbea83f..d1663083d903 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -186,11 +186,11 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
extern char *__bad_type_size(void);
-#define SYSCALL_FIELD(type, name) \
- sizeof(type) != sizeof(trace.name) ? \
+#define SYSCALL_FIELD(type, field, name) \
+ sizeof(type) != sizeof(trace.field) ? \
__bad_type_size() : \
- #type, #name, offsetof(typeof(trace), name), \
- sizeof(trace.name), is_signed_type(type)
+ #type, #name, offsetof(typeof(trace), field), \
+ sizeof(trace.field), is_signed_type(type)
static int __init
__set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
@@ -261,7 +261,8 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
int i;
int offset = offsetof(typeof(trace), args);
- ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+ ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+ FILTER_OTHER);
if (ret)
return ret;
@@ -281,11 +282,12 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
struct syscall_trace_exit trace;
int ret;
- ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+ ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+ FILTER_OTHER);
if (ret)
return ret;
- ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
+ ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret),
FILTER_OTHER);
return ret;
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 975cb49e32bf..f8e26ab963ed 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -93,9 +93,11 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
{
struct mm_struct *mm;
- /* convert pages-usec to Mbyte-usec */
- stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / MB;
- stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB;
+ /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
+ stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
+ do_div(stats->coremem, 1000 * KB);
+ stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
+ do_div(stats->virtmem, 1000 * KB);
mm = get_task_mm(p);
if (mm) {
/* adjust to KB unit */
@@ -123,27 +125,28 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
static void __acct_update_integrals(struct task_struct *tsk,
cputime_t utime, cputime_t stime)
{
- if (likely(tsk->mm)) {
- cputime_t time, dtime;
- struct timeval value;
- unsigned long flags;
- u64 delta;
-
- local_irq_save(flags);
- time = stime + utime;
- dtime = time - tsk->acct_timexpd;
- jiffies_to_timeval(cputime_to_jiffies(dtime), &value);
- delta = value.tv_sec;
- delta = delta * USEC_PER_SEC + value.tv_usec;
-
- if (delta == 0)
- goto out;
- tsk->acct_timexpd = time;
- tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
- tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
- out:
- local_irq_restore(flags);
- }
+ cputime_t time, dtime;
+ u64 delta;
+
+ if (!likely(tsk->mm))
+ return;
+
+ time = stime + utime;
+ dtime = time - tsk->acct_timexpd;
+ /* Avoid division: cputime_t is often in nanoseconds already. */
+ delta = cputime_to_nsecs(dtime);
+
+ if (delta < TICK_NSEC)
+ return;
+
+ tsk->acct_timexpd = time;
+ /*
+ * Divide by 1024 to avoid overflow, and to avoid division.
+ * The final unit reported to userspace is Mbyte-usecs,
+ * the rest of the math is done in xacct_add_tsk.
+ */
+ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
+ tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
}
/**
@@ -153,9 +156,12 @@ static void __acct_update_integrals(struct task_struct *tsk,
void acct_update_integrals(struct task_struct *tsk)
{
cputime_t utime, stime;
+ unsigned long flags;
+ local_irq_save(flags);
task_cputime(tsk, &utime, &stime);
__acct_update_integrals(tsk, utime, stime);
+ local_irq_restore(flags);
}
/**
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 61a0264e28f9..16e13d8628a3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -301,11 +301,26 @@ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */
static LIST_HEAD(workqueues); /* PR: list of all workqueues */
static bool workqueue_freezing; /* PL: have wqs started freezing? */
-static cpumask_var_t wq_unbound_cpumask; /* PL: low level cpumask for all unbound wqs */
+/* PL: allowable cpus for unbound wqs and work items */
+static cpumask_var_t wq_unbound_cpumask;
+
+/* CPU where unbound work was last round robin scheduled from this CPU */
+static DEFINE_PER_CPU(int, wq_rr_cpu_last);
+
+/*
+ * Local execution of unbound work items is no longer guaranteed. The
+ * following always forces round-robin CPU selection on unbound work items
+ * to uncover usages which depend on it.
+ */
+#ifdef CONFIG_DEBUG_WQ_FORCE_RR_CPU
+static bool wq_debug_force_rr_cpu = true;
+#else
+static bool wq_debug_force_rr_cpu = false;
+#endif
+module_param_named(debug_force_rr_cpu, wq_debug_force_rr_cpu, bool, 0644);
/* the per-cpu worker pools */
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],
- cpu_worker_pools);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS], cpu_worker_pools);
static DEFINE_IDR(worker_pool_idr); /* PR: idr of all pools */
@@ -570,6 +585,16 @@ static struct pool_workqueue *unbound_pwq_by_node(struct workqueue_struct *wq,
int node)
{
assert_rcu_or_wq_mutex_or_pool_mutex(wq);
+
+ /*
+ * XXX: @node can be NUMA_NO_NODE if CPU goes offline while a
+ * delayed item is pending. The plan is to keep CPU -> NODE
+ * mapping valid and stable across CPU on/offlines. Once that
+ * happens, this workaround can be removed.
+ */
+ if (unlikely(node == NUMA_NO_NODE))
+ return wq->dfl_pwq;
+
return rcu_dereference_raw(wq->numa_pwq_tbl[node]);
}
@@ -1298,6 +1323,39 @@ static bool is_chained_work(struct workqueue_struct *wq)
return worker && worker->current_pwq->wq == wq;
}
+/*
+ * When queueing an unbound work item to a wq, prefer local CPU if allowed
+ * by wq_unbound_cpumask. Otherwise, round robin among the allowed ones to
+ * avoid perturbing sensitive tasks.
+ */
+static int wq_select_unbound_cpu(int cpu)
+{
+ static bool printed_dbg_warning;
+ int new_cpu;
+
+ if (likely(!wq_debug_force_rr_cpu)) {
+ if (cpumask_test_cpu(cpu, wq_unbound_cpumask))
+ return cpu;
+ } else if (!printed_dbg_warning) {
+ pr_warn("workqueue: round-robin CPU selection forced, expect performance impact\n");
+ printed_dbg_warning = true;
+ }
+
+ if (cpumask_empty(wq_unbound_cpumask))
+ return cpu;
+
+ new_cpu = __this_cpu_read(wq_rr_cpu_last);
+ new_cpu = cpumask_next_and(new_cpu, wq_unbound_cpumask, cpu_online_mask);
+ if (unlikely(new_cpu >= nr_cpu_ids)) {
+ new_cpu = cpumask_first_and(wq_unbound_cpumask, cpu_online_mask);
+ if (unlikely(new_cpu >= nr_cpu_ids))
+ return cpu;
+ }
+ __this_cpu_write(wq_rr_cpu_last, new_cpu);
+
+ return new_cpu;
+}
+
static void __queue_work(int cpu, struct workqueue_struct *wq,
struct work_struct *work)
{
@@ -1323,7 +1381,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
return;
retry:
if (req_cpu == WORK_CPU_UNBOUND)
- cpu = raw_smp_processor_id();
+ cpu = wq_select_unbound_cpu(raw_smp_processor_id());
/* pwq which will be used unless @work is executing elsewhere */
if (!(wq->flags & WQ_UNBOUND))
@@ -1464,13 +1522,13 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
timer_stats_timer_set_start_info(&dwork->timer);
dwork->wq = wq;
- /* timer isn't guaranteed to run in this cpu, record earlier */
- if (cpu == WORK_CPU_UNBOUND)
- cpu = raw_smp_processor_id();
dwork->cpu = cpu;
timer->expires = jiffies + delay;
- add_timer_on(timer, cpu);
+ if (unlikely(cpu != WORK_CPU_UNBOUND))
+ add_timer_on(timer, cpu);
+ else
+ add_timer(timer);
}
/**
@@ -2355,7 +2413,8 @@ static void check_flush_dependency(struct workqueue_struct *target_wq,
WARN_ONCE(current->flags & PF_MEMALLOC,
"workqueue: PF_MEMALLOC task %d(%s) is flushing !WQ_MEM_RECLAIM %s:%pf",
current->pid, current->comm, target_wq->name, target_func);
- WARN_ONCE(worker && (worker->current_pwq->wq->flags & WQ_MEM_RECLAIM),
+ WARN_ONCE(worker && ((worker->current_pwq->wq->flags &
+ (WQ_MEM_RECLAIM | __WQ_LEGACY)) == WQ_MEM_RECLAIM),
"workqueue: WQ_MEM_RECLAIM %s:%pf is flushing !WQ_MEM_RECLAIM %s:%pf",
worker->current_pwq->wq->name, worker->current_func,
target_wq->name, target_func);