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-rw-r--r--kernel/async.c8
-rw-r--r--kernel/exit.c17
-rw-r--r--kernel/extable.c2
-rw-r--r--kernel/futex.c2
-rw-r--r--kernel/printk/printk.c2
-rw-r--r--kernel/sched/Makefile6
-rw-r--r--kernel/sched/clock.c128
-rw-r--r--kernel/sched/completion.c2
-rw-r--r--kernel/sched/core.c772
-rw-r--r--kernel/sched/cputime.c16
-rw-r--r--kernel/sched/deadline.c894
-rw-r--r--kernel/sched/debug.c17
-rw-r--r--kernel/sched/fair.c451
-rw-r--r--kernel/sched/features.h2
-rw-r--r--kernel/sched/idle.c1
-rw-r--r--kernel/sched/loadavg.c51
-rw-r--r--kernel/sched/rt.c323
-rw-r--r--kernel/sched/sched.h113
-rw-r--r--kernel/sched/topology.c430
-rw-r--r--kernel/sched/wait.c441
-rw-r--r--kernel/sched/wait_bit.c286
-rw-r--r--kernel/smp.c16
-rw-r--r--kernel/time/clocksource.c3
-rw-r--r--kernel/time/tick-sched.c11
-rw-r--r--kernel/workqueue.c4
25 files changed, 2413 insertions, 1585 deletions
diff --git a/kernel/async.c b/kernel/async.c
index d2edd6efec56..2cbd3dd5940d 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -114,14 +114,14 @@ static void async_run_entry_fn(struct work_struct *work)
ktime_t uninitialized_var(calltime), delta, rettime;
/* 1) run (and print duration) */
- if (initcall_debug && system_state == SYSTEM_BOOTING) {
+ if (initcall_debug && system_state < SYSTEM_RUNNING) {
pr_debug("calling %lli_%pF @ %i\n",
(long long)entry->cookie,
entry->func, task_pid_nr(current));
calltime = ktime_get();
}
entry->func(entry->data, entry->cookie);
- if (initcall_debug && system_state == SYSTEM_BOOTING) {
+ if (initcall_debug && system_state < SYSTEM_RUNNING) {
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
pr_debug("initcall %lli_%pF returned 0 after %lld usecs\n",
@@ -284,14 +284,14 @@ void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain
{
ktime_t uninitialized_var(starttime), delta, endtime;
- if (initcall_debug && system_state == SYSTEM_BOOTING) {
+ if (initcall_debug && system_state < SYSTEM_RUNNING) {
pr_debug("async_waiting @ %i\n", task_pid_nr(current));
starttime = ktime_get();
}
wait_event(async_done, lowest_in_progress(domain) >= cookie);
- if (initcall_debug && system_state == SYSTEM_BOOTING) {
+ if (initcall_debug && system_state < SYSTEM_RUNNING) {
endtime = ktime_get();
delta = ktime_sub(endtime, starttime);
diff --git a/kernel/exit.c b/kernel/exit.c
index 516acdb0e0ec..c63226283aef 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -318,19 +318,6 @@ void rcuwait_wake_up(struct rcuwait *w)
rcu_read_unlock();
}
-struct task_struct *try_get_task_struct(struct task_struct **ptask)
-{
- struct task_struct *task;
-
- rcu_read_lock();
- task = task_rcu_dereference(ptask);
- if (task)
- get_task_struct(task);
- rcu_read_unlock();
-
- return task;
-}
-
/*
* Determine if a process group is "orphaned", according to the POSIX
* definition in 2.2.2.52. Orphaned process groups are not to be affected
@@ -1004,7 +991,7 @@ struct wait_opts {
int __user *wo_stat;
struct rusage __user *wo_rusage;
- wait_queue_t child_wait;
+ wait_queue_entry_t child_wait;
int notask_error;
};
@@ -1541,7 +1528,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
return 0;
}
-static int child_wait_callback(wait_queue_t *wait, unsigned mode,
+static int child_wait_callback(wait_queue_entry_t *wait, unsigned mode,
int sync, void *key)
{
struct wait_opts *wo = container_of(wait, struct wait_opts,
diff --git a/kernel/extable.c b/kernel/extable.c
index 2676d7f8baf6..0fbdd8582f08 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -75,7 +75,7 @@ int core_kernel_text(unsigned long addr)
addr < (unsigned long)_etext)
return 1;
- if (system_state == SYSTEM_BOOTING &&
+ if (system_state < SYSTEM_RUNNING &&
init_kernel_text(addr))
return 1;
return 0;
diff --git a/kernel/futex.c b/kernel/futex.c
index 357348a6cf6b..d6cf71d08f21 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -225,7 +225,7 @@ struct futex_pi_state {
* @requeue_pi_key: the requeue_pi target futex key
* @bitset: bitset for the optional bitmasked wakeup
*
- * We use this hashed waitqueue, instead of a normal wait_queue_t, so
+ * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so
* we can wake only the relevant ones (hashed queues may be shared).
*
* A futex_q has a woken state, just like tasks have TASK_RUNNING.
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a1db38abac5b..bd53ea579dc8 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1175,7 +1175,7 @@ static void boot_delay_msec(int level)
unsigned long long k;
unsigned long timeout;
- if ((boot_delay == 0 || system_state != SYSTEM_BOOTING)
+ if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING)
|| suppress_message_printing(level)) {
return;
}
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 89ab6758667b..53f0164ed362 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -16,9 +16,9 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif
obj-y += core.o loadavg.o clock.o cputime.o
-obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
-obj-y += wait.o swait.o completion.o idle.o
-obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o
+obj-y += idle_task.o fair.o rt.o deadline.o
+obj-y += wait.o wait_bit.o swait.o completion.o idle.o
+obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o
obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 00a45c45beca..ca0f8fc945c6 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -64,6 +64,7 @@
#include <linux/workqueue.h>
#include <linux/compiler.h>
#include <linux/tick.h>
+#include <linux/init.h>
/*
* Scheduler clock - returns current time in nanosec units.
@@ -124,14 +125,27 @@ int sched_clock_stable(void)
return static_branch_likely(&__sched_clock_stable);
}
+static void __scd_stamp(struct sched_clock_data *scd)
+{
+ scd->tick_gtod = ktime_get_ns();
+ scd->tick_raw = sched_clock();
+}
+
static void __set_sched_clock_stable(void)
{
- struct sched_clock_data *scd = this_scd();
+ struct sched_clock_data *scd;
/*
+ * Since we're still unstable and the tick is already running, we have
+ * to disable IRQs in order to get a consistent scd->tick* reading.
+ */
+ local_irq_disable();
+ scd = this_scd();
+ /*
* Attempt to make the (initial) unstable->stable transition continuous.
*/
__sched_clock_offset = (scd->tick_gtod + __gtod_offset) - (scd->tick_raw);
+ local_irq_enable();
printk(KERN_INFO "sched_clock: Marking stable (%lld, %lld)->(%lld, %lld)\n",
scd->tick_gtod, __gtod_offset,
@@ -141,8 +155,38 @@ static void __set_sched_clock_stable(void)
tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE);
}
+/*
+ * If we ever get here, we're screwed, because we found out -- typically after
+ * the fact -- that TSC wasn't good. This means all our clocksources (including
+ * ktime) could have reported wrong values.
+ *
+ * What we do here is an attempt to fix up and continue sort of where we left
+ * off in a coherent manner.
+ *
+ * The only way to fully avoid random clock jumps is to boot with:
+ * "tsc=unstable".
+ */
static void __sched_clock_work(struct work_struct *work)
{
+ struct sched_clock_data *scd;
+ int cpu;
+
+ /* take a current timestamp and set 'now' */
+ preempt_disable();
+ scd = this_scd();
+ __scd_stamp(scd);
+ scd->clock = scd->tick_gtod + __gtod_offset;
+ preempt_enable();
+
+ /* clone to all CPUs */
+ for_each_possible_cpu(cpu)
+ per_cpu(sched_clock_data, cpu) = *scd;
+
+ printk(KERN_WARNING "TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.\n");
+ printk(KERN_INFO "sched_clock: Marking unstable (%lld, %lld)<-(%lld, %lld)\n",
+ scd->tick_gtod, __gtod_offset,
+ scd->tick_raw, __sched_clock_offset);
+
static_branch_disable(&__sched_clock_stable);
}
@@ -150,27 +194,11 @@ static DECLARE_WORK(sched_clock_work, __sched_clock_work);
static void __clear_sched_clock_stable(void)
{
- struct sched_clock_data *scd = this_scd();
-
- /*
- * Attempt to make the stable->unstable transition continuous.
- *
- * Trouble is, this is typically called from the TSC watchdog
- * timer, which is late per definition. This means the tick
- * values can already be screwy.
- *
- * Still do what we can.
- */
- __gtod_offset = (scd->tick_raw + __sched_clock_offset) - (scd->tick_gtod);
-
- printk(KERN_INFO "sched_clock: Marking unstable (%lld, %lld)<-(%lld, %lld)\n",
- scd->tick_gtod, __gtod_offset,
- scd->tick_raw, __sched_clock_offset);
+ if (!sched_clock_stable())
+ return;
tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE);
-
- if (sched_clock_stable())
- schedule_work(&sched_clock_work);
+ schedule_work(&sched_clock_work);
}
void clear_sched_clock_stable(void)
@@ -183,7 +211,11 @@ void clear_sched_clock_stable(void)
__clear_sched_clock_stable();
}
-void sched_clock_init_late(void)
+/*
+ * We run this as late_initcall() such that it runs after all built-in drivers,
+ * notably: acpi_processor and intel_idle, which can mark the TSC as unstable.
+ */
+static int __init sched_clock_init_late(void)
{
sched_clock_running = 2;
/*
@@ -197,7 +229,10 @@ void sched_clock_init_late(void)
if (__sched_clock_stable_early)
__set_sched_clock_stable();
+
+ return 0;
}
+late_initcall(sched_clock_init_late);
/*
* min, max except they take wrapping into account
@@ -347,21 +382,38 @@ void sched_clock_tick(void)
{
struct sched_clock_data *scd;
+ if (sched_clock_stable())
+ return;
+
+ if (unlikely(!sched_clock_running))
+ return;
+
WARN_ON_ONCE(!irqs_disabled());
+ scd = this_scd();
+ __scd_stamp(scd);
+ sched_clock_local(scd);
+}
+
+void sched_clock_tick_stable(void)
+{
+ u64 gtod, clock;
+
+ if (!sched_clock_stable())
+ return;
+
/*
- * Update these values even if sched_clock_stable(), because it can
- * become unstable at any point in time at which point we need some
- * values to fall back on.
+ * Called under watchdog_lock.
*
- * XXX arguably we can skip this if we expose tsc_clocksource_reliable
+ * The watchdog just found this TSC to (still) be stable, so now is a
+ * good moment to update our __gtod_offset. Because once we find the
+ * TSC to be unstable, any computation will be computing crap.
*/
- scd = this_scd();
- scd->tick_raw = sched_clock();
- scd->tick_gtod = ktime_get_ns();
-
- if (!sched_clock_stable() && likely(sched_clock_running))
- sched_clock_local(scd);
+ local_irq_disable();
+ gtod = ktime_get_ns();
+ clock = sched_clock();
+ __gtod_offset = (clock + __sched_clock_offset) - gtod;
+ local_irq_enable();
}
/*
@@ -374,15 +426,21 @@ void sched_clock_idle_sleep_event(void)
EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
/*
- * We just idled delta nanoseconds (called with irqs disabled):
+ * We just idled; resync with ktime.
*/
-void sched_clock_idle_wakeup_event(u64 delta_ns)
+void sched_clock_idle_wakeup_event(void)
{
- if (timekeeping_suspended)
+ unsigned long flags;
+
+ if (sched_clock_stable())
+ return;
+
+ if (unlikely(timekeeping_suspended))
return;
+ local_irq_save(flags);
sched_clock_tick();
- touch_softlockup_watchdog_sched();
+ local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 53f9558fa925..13fc5ae9bf2f 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -66,7 +66,7 @@ do_wait_for_common(struct completion *x,
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
- __add_wait_queue_tail_exclusive(&x->wait, &wait);
+ __add_wait_queue_entry_tail_exclusive(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5b60f3a8343f..17c667b427b4 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -10,6 +10,7 @@
#include <uapi/linux/sched/types.h>
#include <linux/sched/loadavg.h>
#include <linux/sched/hotplug.h>
+#include <linux/wait_bit.h>
#include <linux/cpuset.h>
#include <linux/delayacct.h>
#include <linux/init_task.h>
@@ -788,36 +789,6 @@ void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
dequeue_task(rq, p, flags);
}
-void sched_set_stop_task(int cpu, struct task_struct *stop)
-{
- struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
- struct task_struct *old_stop = cpu_rq(cpu)->stop;
-
- if (stop) {
- /*
- * Make it appear like a SCHED_FIFO task, its something
- * userspace knows about and won't get confused about.
- *
- * Also, it will make PI more or less work without too
- * much confusion -- but then, stop work should not
- * rely on PI working anyway.
- */
- sched_setscheduler_nocheck(stop, SCHED_FIFO, &param);
-
- stop->sched_class = &stop_sched_class;
- }
-
- cpu_rq(cpu)->stop = stop;
-
- if (old_stop) {
- /*
- * Reset it back to a normal scheduling class so that
- * it can die in pieces.
- */
- old_stop->sched_class = &rt_sched_class;
- }
-}
-
/*
* __normal_prio - return the priority that is based on the static prio
*/
@@ -1588,6 +1559,36 @@ static void update_avg(u64 *avg, u64 sample)
*avg += diff >> 3;
}
+void sched_set_stop_task(int cpu, struct task_struct *stop)
+{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+ struct task_struct *old_stop = cpu_rq(cpu)->stop;
+
+ if (stop) {
+ /*
+ * Make it appear like a SCHED_FIFO task, its something
+ * userspace knows about and won't get confused about.
+ *
+ * Also, it will make PI more or less work without too
+ * much confusion -- but then, stop work should not
+ * rely on PI working anyway.
+ */
+ sched_setscheduler_nocheck(stop, SCHED_FIFO, &param);
+
+ stop->sched_class = &stop_sched_class;
+ }
+
+ cpu_rq(cpu)->stop = stop;
+
+ if (old_stop) {
+ /*
+ * Reset it back to a normal scheduling class so that
+ * it can die in pieces.
+ */
+ old_stop->sched_class = &rt_sched_class;
+ }
+}
+
#else
static inline int __set_cpus_allowed_ptr(struct task_struct *p,
@@ -1731,7 +1732,7 @@ void sched_ttwu_pending(void)
{
struct rq *rq = this_rq();
struct llist_node *llist = llist_del_all(&rq->wake_list);
- struct task_struct *p;
+ struct task_struct *p, *t;
struct rq_flags rf;
if (!llist)
@@ -1740,17 +1741,8 @@ void sched_ttwu_pending(void)
rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
- while (llist) {
- int wake_flags = 0;
-
- p = llist_entry(llist, struct task_struct, wake_entry);
- llist = llist_next(llist);
-
- if (p->sched_remote_wakeup)
- wake_flags = WF_MIGRATED;
-
- ttwu_do_activate(rq, p, wake_flags, &rf);
- }
+ llist_for_each_entry_safe(p, t, llist, wake_entry)
+ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0, &rf);
rq_unlock_irqrestore(rq, &rf);
}
@@ -2148,23 +2140,6 @@ int wake_up_state(struct task_struct *p, unsigned int state)
}
/*
- * This function clears the sched_dl_entity static params.
- */
-void __dl_clear_params(struct task_struct *p)
-{
- struct sched_dl_entity *dl_se = &p->dl;
-
- dl_se->dl_runtime = 0;
- dl_se->dl_deadline = 0;
- dl_se->dl_period = 0;
- dl_se->flags = 0;
- dl_se->dl_bw = 0;
-
- dl_se->dl_throttled = 0;
- dl_se->dl_yielded = 0;
-}
-
-/*
* Perform scheduler related setup for a newly forked process p.
* p is forked by current.
*
@@ -2193,6 +2168,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
RB_CLEAR_NODE(&p->dl.rb_node);
init_dl_task_timer(&p->dl);
+ init_dl_inactive_task_timer(&p->dl);
__dl_clear_params(p);
INIT_LIST_HEAD(&p->rt.run_list);
@@ -2430,7 +2406,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
unsigned long to_ratio(u64 period, u64 runtime)
{
if (runtime == RUNTIME_INF)
- return 1ULL << 20;
+ return BW_UNIT;
/*
* Doing this here saves a lot of checks in all
@@ -2440,93 +2416,9 @@ unsigned long to_ratio(u64 period, u64 runtime)
if (period == 0)
return 0;
- return div64_u64(runtime << 20, period);
+ return div64_u64(runtime << BW_SHIFT, period);
}
-#ifdef CONFIG_SMP
-inline struct dl_bw *dl_bw_of(int i)
-{
- RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
- "sched RCU must be held");
- return &cpu_rq(i)->rd->dl_bw;
-}
-
-static inline int dl_bw_cpus(int i)
-{
- struct root_domain *rd = cpu_rq(i)->rd;
- int cpus = 0;
-
- RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
- "sched RCU must be held");
- for_each_cpu_and(i, rd->span, cpu_active_mask)
- cpus++;
-
- return cpus;
-}
-#else
-inline struct dl_bw *dl_bw_of(int i)
-{
- return &cpu_rq(i)->dl.dl_bw;
-}
-
-static inline int dl_bw_cpus(int i)
-{
- return 1;
-}
-#endif
-
-/*
- * We must be sure that accepting a new task (or allowing changing the
- * parameters of an existing one) is consistent with the bandwidth
- * constraints. If yes, this function also accordingly updates the currently
- * allocated bandwidth to reflect the new situation.
- *
- * This function is called while holding p's rq->lock.
- *
- * XXX we should delay bw change until the task's 0-lag point, see
- * __setparam_dl().
- */
-static int dl_overflow(struct task_struct *p, int policy,
- const struct sched_attr *attr)
-{
-
- struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
- u64 period = attr->sched_period ?: attr->sched_deadline;
- u64 runtime = attr->sched_runtime;
- u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
- int cpus, err = -1;
-
- /* !deadline task may carry old deadline bandwidth */
- if (new_bw == p->dl.dl_bw && task_has_dl_policy(p))
- return 0;
-
- /*
- * Either if a task, enters, leave, or stays -deadline but changes
- * its parameters, we may need to update accordingly the total
- * allocated bandwidth of the container.
- */
- raw_spin_lock(&dl_b->lock);
- cpus = dl_bw_cpus(task_cpu(p));
- if (dl_policy(policy) && !task_has_dl_policy(p) &&
- !__dl_overflow(dl_b, cpus, 0, new_bw)) {
- __dl_add(dl_b, new_bw);
- err = 0;
- } else if (dl_policy(policy) && task_has_dl_policy(p) &&
- !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
- __dl_clear(dl_b, p->dl.dl_bw);
- __dl_add(dl_b, new_bw);
- err = 0;
- } else if (!dl_policy(policy) && task_has_dl_policy(p)) {
- __dl_clear(dl_b, p->dl.dl_bw);
- err = 0;
- }
- raw_spin_unlock(&dl_b->lock);
-
- return err;
-}
-
-extern void init_dl_bw(struct dl_bw *dl_b);
-
/*
* wake_up_new_task - wake up a newly created task for the first time.
*
@@ -3687,7 +3579,7 @@ asmlinkage __visible void __sched preempt_schedule_irq(void)
exception_exit(prev_state);
}
-int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
+int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags,
void *key)
{
return try_to_wake_up(curr->private, mode, wake_flags);
@@ -4009,46 +3901,6 @@ static struct task_struct *find_process_by_pid(pid_t pid)
}
/*
- * This function initializes the sched_dl_entity of a newly becoming
- * SCHED_DEADLINE task.
- *
- * Only the static values are considered here, the actual runtime and the
- * absolute deadline will be properly calculated when the task is enqueued
- * for the first time with its new policy.
- */
-static void
-__setparam_dl(struct task_struct *p, const struct sched_attr *attr)
-{
- struct sched_dl_entity *dl_se = &p->dl;
-
- dl_se->dl_runtime = attr->sched_runtime;
- dl_se->dl_deadline = attr->sched_deadline;
- dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
- dl_se->flags = attr->sched_flags;
- dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
-
- /*
- * Changing the parameters of a task is 'tricky' and we're not doing
- * the correct thing -- also see task_dead_dl() and switched_from_dl().
- *
- * What we SHOULD do is delay the bandwidth release until the 0-lag
- * point. This would include retaining the task_struct until that time
- * and change dl_overflow() to not immediately decrement the current
- * amount.
- *
- * Instead we retain the current runtime/deadline and let the new
- * parameters take effect after the current reservation period lapses.
- * This is safe (albeit pessimistic) because the 0-lag point is always
- * before the current scheduling deadline.
- *
- * We can still have temporary overloads because we do not delay the
- * change in bandwidth until that time; so admission control is
- * not on the safe side. It does however guarantee tasks will never
- * consume more than promised.
- */
-}
-
-/*
* sched_setparam() passes in -1 for its policy, to let the functions
* it calls know not to change it.
*/
@@ -4101,59 +3953,6 @@ static void __setscheduler(struct rq *rq, struct task_struct *p,
p->sched_class = &fair_sched_class;
}
-static void
-__getparam_dl(struct task_struct *p, struct sched_attr *attr)
-{
- struct sched_dl_entity *dl_se = &p->dl;
-
- attr->sched_priority = p->rt_priority;
- attr->sched_runtime = dl_se->dl_runtime;
- attr->sched_deadline = dl_se->dl_deadline;
- attr->sched_period = dl_se->dl_period;
- attr->sched_flags = dl_se->flags;
-}
-
-/*
- * This function validates the new parameters of a -deadline task.
- * We ask for the deadline not being zero, and greater or equal
- * than the runtime, as well as the period of being zero or
- * greater than deadline. Furthermore, we have to be sure that
- * user parameters are above the internal resolution of 1us (we
- * check sched_runtime only since it is always the smaller one) and
- * below 2^63 ns (we have to check both sched_deadline and
- * sched_period, as the latter can be zero).
- */
-static bool
-__checkparam_dl(const struct sched_attr *attr)
-{
- /* deadline != 0 */
- if (attr->sched_deadline == 0)
- return false;
-
- /*
- * Since we truncate DL_SCALE bits, make sure we're at least
- * that big.
- */
- if (attr->sched_runtime < (1ULL << DL_SCALE))
- return false;
-
- /*
- * Since we use the MSB for wrap-around and sign issues, make
- * sure it's not set (mind that period can be equal to zero).
- */
- if (attr->sched_deadline & (1ULL << 63) ||
- attr->sched_period & (1ULL << 63))
- return false;
-
- /* runtime <= deadline <= period (if period != 0) */
- if ((attr->sched_period != 0 &&
- attr->sched_period < attr->sched_deadline) ||
- attr->sched_deadline < attr->sched_runtime)
- return false;
-
- return true;
-}
-
/*
* Check the target process has a UID that matches the current process's:
*/
@@ -4170,19 +3969,6 @@ static bool check_same_owner(struct task_struct *p)
return match;
}
-static bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
-{
- struct sched_dl_entity *dl_se = &p->dl;
-
- if (dl_se->dl_runtime != attr->sched_runtime ||
- dl_se->dl_deadline != attr->sched_deadline ||
- dl_se->dl_period != attr->sched_period ||
- dl_se->flags != attr->sched_flags)
- return true;
-
- return false;
-}
-
static int __sched_setscheduler(struct task_struct *p,
const struct sched_attr *attr,
bool user, bool pi)
@@ -4197,8 +3983,8 @@ static int __sched_setscheduler(struct task_struct *p,
int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK;
struct rq *rq;
- /* May grab non-irq protected spin_locks: */
- BUG_ON(in_interrupt());
+ /* The pi code expects interrupts enabled */
+ BUG_ON(pi && in_interrupt());
recheck:
/* Double check policy once rq lock held: */
if (policy < 0) {
@@ -4211,7 +3997,8 @@ recheck:
return -EINVAL;
}
- if (attr->sched_flags & ~(SCHED_FLAG_RESET_ON_FORK))
+ if (attr->sched_flags &
+ ~(SCHED_FLAG_RESET_ON_FORK | SCHED_FLAG_RECLAIM))
return -EINVAL;
/*
@@ -4362,7 +4149,7 @@ change:
* of a SCHED_DEADLINE task) we need to check if enough bandwidth
* is available.
*/
- if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) {
+ if ((dl_policy(policy) || dl_task(p)) && sched_dl_overflow(p, policy, attr)) {
task_rq_unlock(rq, p, &rf);
return -EBUSY;
}
@@ -5463,26 +5250,17 @@ void init_idle(struct task_struct *idle, int cpu)
#endif
}
+#ifdef CONFIG_SMP
+
int cpuset_cpumask_can_shrink(const struct cpumask *cur,
const struct cpumask *trial)
{
- int ret = 1, trial_cpus;
- struct dl_bw *cur_dl_b;
- unsigned long flags;
+ int ret = 1;
if (!cpumask_weight(cur))
return ret;
- rcu_read_lock_sched();
- cur_dl_b = dl_bw_of(cpumask_any(cur));
- trial_cpus = cpumask_weight(trial);
-
- raw_spin_lock_irqsave(&cur_dl_b->lock, flags);
- if (cur_dl_b->bw != -1 &&
- cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw)
- ret = 0;
- raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);
- rcu_read_unlock_sched();
+ ret = dl_cpuset_cpumask_can_shrink(cur, trial);
return ret;
}
@@ -5506,43 +5284,14 @@ int task_can_attach(struct task_struct *p,
goto out;
}
-#ifdef CONFIG_SMP
if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span,
- cs_cpus_allowed)) {
- unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,
- cs_cpus_allowed);
- struct dl_bw *dl_b;
- bool overflow;
- int cpus;
- unsigned long flags;
-
- rcu_read_lock_sched();
- dl_b = dl_bw_of(dest_cpu);
- raw_spin_lock_irqsave(&dl_b->lock, flags);
- cpus = dl_bw_cpus(dest_cpu);
- overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
- if (overflow)
- ret = -EBUSY;
- else {
- /*
- * We reserve space for this task in the destination
- * root_domain, as we can't fail after this point.
- * We will free resources in the source root_domain
- * later on (see set_cpus_allowed_dl()).
- */
- __dl_add(dl_b, p->dl.dl_bw);
- }
- raw_spin_unlock_irqrestore(&dl_b->lock, flags);
- rcu_read_unlock_sched();
+ cs_cpus_allowed))
+ ret = dl_task_can_attach(p, cs_cpus_allowed);
- }
-#endif
out:
return ret;
}
-#ifdef CONFIG_SMP
-
bool sched_smp_initialized __read_mostly;
#ifdef CONFIG_NUMA_BALANCING
@@ -5805,23 +5554,8 @@ static void cpuset_cpu_active(void)
static int cpuset_cpu_inactive(unsigned int cpu)
{
- unsigned long flags;
- struct dl_bw *dl_b;
- bool overflow;
- int cpus;
-
if (!cpuhp_tasks_frozen) {
- rcu_read_lock_sched();
- dl_b = dl_bw_of(cpu);
-
- raw_spin_lock_irqsave(&dl_b->lock, flags);
- cpus = dl_bw_cpus(cpu);
- overflow = __dl_overflow(dl_b, cpus, 0, 0);
- raw_spin_unlock_irqrestore(&dl_b->lock, flags);
-
- rcu_read_unlock_sched();
-
- if (overflow)
+ if (dl_cpu_busy(cpu))
return -EBUSY;
cpuset_update_active_cpus();
} else {
@@ -5952,7 +5686,6 @@ void __init sched_init_smp(void)
cpumask_var_t non_isolated_cpus;
alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
- alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
sched_init_numa();
@@ -5962,7 +5695,7 @@ void __init sched_init_smp(void)
* happen.
*/
mutex_lock(&sched_domains_mutex);
- init_sched_domains(cpu_active_mask);
+ sched_init_domains(cpu_active_mask);
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
@@ -5978,7 +5711,6 @@ void __init sched_init_smp(void)
init_sched_dl_class();
sched_init_smt();
- sched_clock_init_late();
sched_smp_initialized = true;
}
@@ -5994,7 +5726,6 @@ early_initcall(migration_init);
void __init sched_init_smp(void)
{
sched_init_granularity();
- sched_clock_init_late();
}
#endif /* CONFIG_SMP */
@@ -6020,28 +5751,13 @@ static struct kmem_cache *task_group_cache __read_mostly;
DECLARE_PER_CPU(cpumask_var_t, load_balance_mask);
DECLARE_PER_CPU(cpumask_var_t, select_idle_mask);
-#define WAIT_TABLE_BITS 8
-#define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
-static wait_queue_head_t bit_wait_table[WAIT_TABLE_SIZE] __cacheline_aligned;
-
-wait_queue_head_t *bit_waitqueue(void *word, int bit)
-{
- const int shift = BITS_PER_LONG == 32 ? 5 : 6;
- unsigned long val = (unsigned long)word << shift | bit;
-
- return bit_wait_table + hash_long(val, WAIT_TABLE_BITS);
-}
-EXPORT_SYMBOL(bit_waitqueue);
-
void __init sched_init(void)
{
int i, j;
unsigned long alloc_size = 0, ptr;
sched_clock_init();
-
- for (i = 0; i < WAIT_TABLE_SIZE; i++)
- init_waitqueue_head(bit_wait_table + i);
+ wait_bit_init();
#ifdef CONFIG_FAIR_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
@@ -6193,7 +5909,6 @@ void __init sched_init(void)
calc_load_update = jiffies + LOAD_FREQ;
#ifdef CONFIG_SMP
- zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
/* May be allocated at isolcpus cmdline parse time */
if (cpu_isolated_map == NULL)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
@@ -6245,8 +5960,10 @@ void ___might_sleep(const char *file, int line, int preempt_offset)
if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
!is_idle_task(current)) ||
- system_state != SYSTEM_RUNNING || oops_in_progress)
+ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
+ oops_in_progress)
return;
+
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
prev_jiffy = jiffies;
@@ -6501,385 +6218,6 @@ void sched_move_task(struct task_struct *tsk)
task_rq_unlock(rq, tsk, &rf);
}
-#endif /* CONFIG_CGROUP_SCHED */
-
-#ifdef CONFIG_RT_GROUP_SCHED
-/*
- * Ensure that the real time constraints are schedulable.
- */
-static DEFINE_MUTEX(rt_constraints_mutex);
-
-/* Must be called with tasklist_lock held */
-static inline int tg_has_rt_tasks(struct task_group *tg)
-{
- struct task_struct *g, *p;
-
- /*
- * Autogroups do not have RT tasks; see autogroup_create().
- */
- if (task_group_is_autogroup(tg))
- return 0;
-
- for_each_process_thread(g, p) {
- if (rt_task(p) && task_group(p) == tg)
- return 1;
- }
-
- return 0;
-}
-
-struct rt_schedulable_data {
- struct task_group *tg;
- u64 rt_period;
- u64 rt_runtime;
-};
-
-static int tg_rt_schedulable(struct task_group *tg, void *data)
-{
- struct rt_schedulable_data *d = data;
- struct task_group *child;
- unsigned long total, sum = 0;
- u64 period, runtime;
-
- period = ktime_to_ns(tg->rt_bandwidth.rt_period);
- runtime = tg->rt_bandwidth.rt_runtime;
-
- if (tg == d->tg) {
- period = d->rt_period;
- runtime = d->rt_runtime;
- }
-
- /*
- * Cannot have more runtime than the period.
- */
- if (runtime > period && runtime != RUNTIME_INF)
- return -EINVAL;
-
- /*
- * Ensure we don't starve existing RT tasks.
- */
- if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
- return -EBUSY;
-
- total = to_ratio(period, runtime);
-
- /*
- * Nobody can have more than the global setting allows.
- */
- if (total > to_ratio(global_rt_period(), global_rt_runtime()))
- return -EINVAL;
-
- /*
- * The sum of our children's runtime should not exceed our own.
- */
- list_for_each_entry_rcu(child, &tg->children, siblings) {
- period = ktime_to_ns(child->rt_bandwidth.rt_period);
- runtime = child->rt_bandwidth.rt_runtime;
-
- if (child == d->tg) {
- period = d->rt_period;
- runtime = d->rt_runtime;
- }
-
- sum += to_ratio(period, runtime);
- }
-
- if (sum > total)
- return -EINVAL;
-
- return 0;
-}
-
-static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
-{
- int ret;
-
- struct rt_schedulable_data data = {
- .tg = tg,
- .rt_period = period,
- .rt_runtime = runtime,
- };
-
- rcu_read_lock();
- ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
- rcu_read_unlock();
-
- return ret;
-}
-
-static int tg_set_rt_bandwidth(struct task_group *tg,
- u64 rt_period, u64 rt_runtime)
-{
- int i, err = 0;
-
- /*
- * Disallowing the root group RT runtime is BAD, it would disallow the
- * kernel creating (and or operating) RT threads.
- */
- if (tg == &root_task_group && rt_runtime == 0)
- return -EINVAL;
-
- /* No period doesn't make any sense. */
- if (rt_period == 0)
- return -EINVAL;
-
- mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
- err = __rt_schedulable(tg, rt_period, rt_runtime);
- if (err)
- goto unlock;
-
- raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
- tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
- tg->rt_bandwidth.rt_runtime = rt_runtime;
-
- for_each_possible_cpu(i) {
- struct rt_rq *rt_rq = tg->rt_rq[i];
-
- raw_spin_lock(&rt_rq->rt_runtime_lock);
- rt_rq->rt_runtime = rt_runtime;
- raw_spin_unlock(&rt_rq->rt_runtime_lock);
- }
- raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
-unlock:
- read_unlock(&tasklist_lock);
- mutex_unlock(&rt_constraints_mutex);
-
- return err;
-}
-
-static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
-{
- u64 rt_runtime, rt_period;
-
- rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
- rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
- if (rt_runtime_us < 0)
- rt_runtime = RUNTIME_INF;
-
- return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
-}
-
-static long sched_group_rt_runtime(struct task_group *tg)
-{
- u64 rt_runtime_us;
-
- if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
- return -1;
-
- rt_runtime_us = tg->rt_bandwidth.rt_runtime;
- do_div(rt_runtime_us, NSEC_PER_USEC);
- return rt_runtime_us;
-}
-
-static int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us)
-{
- u64 rt_runtime, rt_period;
-
- rt_period = rt_period_us * NSEC_PER_USEC;
- rt_runtime = tg->rt_bandwidth.rt_runtime;
-
- return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
-}
-
-static long sched_group_rt_period(struct task_group *tg)
-{
- u64 rt_period_us;
-
- rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
- do_div(rt_period_us, NSEC_PER_USEC);
- return rt_period_us;
-}
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-#ifdef CONFIG_RT_GROUP_SCHED
-static int sched_rt_global_constraints(void)
-{
- int ret = 0;
-
- mutex_lock(&rt_constraints_mutex);
- read_lock(&tasklist_lock);
- ret = __rt_schedulable(NULL, 0, 0);
- read_unlock(&tasklist_lock);
- mutex_unlock(&rt_constraints_mutex);
-
- return ret;
-}
-
-static int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
-{
- /* Don't accept realtime tasks when there is no way for them to run */
- if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
- return 0;
-
- return 1;
-}
-
-#else /* !CONFIG_RT_GROUP_SCHED */
-static int sched_rt_global_constraints(void)
-{
- unsigned long flags;
- int i;
-
- raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
- for_each_possible_cpu(i) {
- struct rt_rq *rt_rq = &cpu_rq(i)->rt;
-
- raw_spin_lock(&rt_rq->rt_runtime_lock);
- rt_rq->rt_runtime = global_rt_runtime();
- raw_spin_unlock(&rt_rq->rt_runtime_lock);
- }
- raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
-
- return 0;
-}
-#endif /* CONFIG_RT_GROUP_SCHED */
-
-static int sched_dl_global_validate(void)
-{
- u64 runtime = global_rt_runtime();
- u64 period = global_rt_period();
- u64 new_bw = to_ratio(period, runtime);
- struct dl_bw *dl_b;
- int cpu, ret = 0;
- unsigned long flags;
-
- /*
- * Here we want to check the bandwidth not being set to some
- * value smaller than the currently allocated bandwidth in
- * any of the root_domains.
- *
- * FIXME: Cycling on all the CPUs is overdoing, but simpler than
- * cycling on root_domains... Discussion on different/better
- * solutions is welcome!
- */
- for_each_possible_cpu(cpu) {
- rcu_read_lock_sched();
- dl_b = dl_bw_of(cpu);
-
- raw_spin_lock_irqsave(&dl_b->lock, flags);
- if (new_bw < dl_b->total_bw)
- ret = -EBUSY;
- raw_spin_unlock_irqrestore(&dl_b->lock, flags);
-
- rcu_read_unlock_sched();
-
- if (ret)
- break;
- }
-
- return ret;
-}
-
-static void sched_dl_do_global(void)
-{
- u64 new_bw = -1;
- struct dl_bw *dl_b;
- int cpu;
- unsigned long flags;
-
- def_dl_bandwidth.dl_period = global_rt_period();
- def_dl_bandwidth.dl_runtime = global_rt_runtime();
-
- if (global_rt_runtime() != RUNTIME_INF)
- new_bw = to_ratio(global_rt_period(), global_rt_runtime());
-
- /*
- * FIXME: As above...
- */
- for_each_possible_cpu(cpu) {
- rcu_read_lock_sched();
- dl_b = dl_bw_of(cpu);
-
- raw_spin_lock_irqsave(&dl_b->lock, flags);
- dl_b->bw = new_bw;
- raw_spin_unlock_irqrestore(&dl_b->lock, flags);
-
- rcu_read_unlock_sched();
- }
-}
-
-static int sched_rt_global_validate(void)
-{
- if (sysctl_sched_rt_period <= 0)
- return -EINVAL;
-
- if ((sysctl_sched_rt_runtime != RUNTIME_INF) &&
- (sysctl_sched_rt_runtime > sysctl_sched_rt_period))
- return -EINVAL;
-
- return 0;
-}
-
-static void sched_rt_do_global(void)
-{
- def_rt_bandwidth.rt_runtime = global_rt_runtime();
- def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period());
-}
-
-int sched_rt_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
-{
- int old_period, old_runtime;
- static DEFINE_MUTEX(mutex);
- int ret;
-
- mutex_lock(&mutex);
- old_period = sysctl_sched_rt_period;
- old_runtime = sysctl_sched_rt_runtime;
-
- ret = proc_dointvec(table, write, buffer, lenp, ppos);
-
- if (!ret && write) {
- ret = sched_rt_global_validate();
- if (ret)
- goto undo;
-
- ret = sched_dl_global_validate();
- if (ret)
- goto undo;
-
- ret = sched_rt_global_constraints();
- if (ret)
- goto undo;
-
- sched_rt_do_global();
- sched_dl_do_global();
- }
- if (0) {
-undo:
- sysctl_sched_rt_period = old_period;
- sysctl_sched_rt_runtime = old_runtime;
- }
- mutex_unlock(&mutex);
-
- return ret;
-}
-
-int sched_rr_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
-{
- int ret;
- static DEFINE_MUTEX(mutex);
-
- mutex_lock(&mutex);
- ret = proc_dointvec(table, write, buffer, lenp, ppos);
- /*
- * Make sure that internally we keep jiffies.
- * Also, writing zero resets the timeslice to default:
- */
- if (!ret && write) {
- sched_rr_timeslice =
- sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE :
- msecs_to_jiffies(sysctl_sched_rr_timeslice);
- }
- mutex_unlock(&mutex);
- return ret;
-}
-
-#ifdef CONFIG_CGROUP_SCHED
static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
{
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index aea3135c5d90..67c70e287647 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -615,19 +615,13 @@ static void cputime_adjust(struct task_cputime *curr,
* userspace. Once a task gets some ticks, the monotonicy code at
* 'update' will ensure things converge to the observed ratio.
*/
- if (stime == 0) {
- utime = rtime;
- goto update;
+ if (stime != 0) {
+ if (utime == 0)
+ stime = rtime;
+ else
+ stime = scale_stime(stime, rtime, stime + utime);
}
- if (utime == 0) {
- stime = rtime;
- goto update;
- }
-
- stime = scale_stime(stime, rtime, stime + utime);
-
-update:
/*
* Make sure stime doesn't go backwards; this preserves monotonicity
* for utime because rtime is monotonic.
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a2ce59015642..a84299f44b5d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -17,6 +17,7 @@
#include "sched.h"
#include <linux/slab.h>
+#include <uapi/linux/sched/types.h>
struct dl_bandwidth def_dl_bandwidth;
@@ -43,6 +44,254 @@ static inline int on_dl_rq(struct sched_dl_entity *dl_se)
return !RB_EMPTY_NODE(&dl_se->rb_node);
}
+#ifdef CONFIG_SMP
+static inline struct dl_bw *dl_bw_of(int i)
+{
+ RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+ "sched RCU must be held");
+ return &cpu_rq(i)->rd->dl_bw;
+}
+
+static inline int dl_bw_cpus(int i)
+{
+ struct root_domain *rd = cpu_rq(i)->rd;
+ int cpus = 0;
+
+ RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+ "sched RCU must be held");
+ for_each_cpu_and(i, rd->span, cpu_active_mask)
+ cpus++;
+
+ return cpus;
+}
+#else
+static inline struct dl_bw *dl_bw_of(int i)
+{
+ return &cpu_rq(i)->dl.dl_bw;
+}
+
+static inline int dl_bw_cpus(int i)
+{
+ return 1;
+}
+#endif
+
+static inline
+void add_running_bw(u64 dl_bw, struct dl_rq *dl_rq)
+{
+ u64 old = dl_rq->running_bw;
+
+ lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
+ dl_rq->running_bw += dl_bw;
+ SCHED_WARN_ON(dl_rq->running_bw < old); /* overflow */
+ SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw);
+}
+
+static inline
+void sub_running_bw(u64 dl_bw, struct dl_rq *dl_rq)
+{
+ u64 old = dl_rq->running_bw;
+
+ lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
+ dl_rq->running_bw -= dl_bw;
+ SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */
+ if (dl_rq->running_bw > old)
+ dl_rq->running_bw = 0;
+}
+
+static inline
+void add_rq_bw(u64 dl_bw, struct dl_rq *dl_rq)
+{
+ u64 old = dl_rq->this_bw;
+
+ lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
+ dl_rq->this_bw += dl_bw;
+ SCHED_WARN_ON(dl_rq->this_bw < old); /* overflow */
+}
+
+static inline
+void sub_rq_bw(u64 dl_bw, struct dl_rq *dl_rq)
+{
+ u64 old = dl_rq->this_bw;
+
+ lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
+ dl_rq->this_bw -= dl_bw;
+ SCHED_WARN_ON(dl_rq->this_bw > old); /* underflow */
+ if (dl_rq->this_bw > old)
+ dl_rq->this_bw = 0;
+ SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw);
+}
+
+void dl_change_utilization(struct task_struct *p, u64 new_bw)
+{
+ struct rq *rq;
+
+ if (task_on_rq_queued(p))
+ return;
+
+ rq = task_rq(p);
+ if (p->dl.dl_non_contending) {
+ sub_running_bw(p->dl.dl_bw, &rq->dl);
+ p->dl.dl_non_contending = 0;
+ /*
+ * If the timer handler is currently running and the
+ * timer cannot be cancelled, inactive_task_timer()
+ * will see that dl_not_contending is not set, and
+ * will not touch the rq's active utilization,
+ * so we are still safe.
+ */
+ if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1)
+ put_task_struct(p);
+ }
+ sub_rq_bw(p->dl.dl_bw, &rq->dl);
+ add_rq_bw(new_bw, &rq->dl);
+}
+
+/*
+ * The utilization of a task cannot be immediately removed from
+ * the rq active utilization (running_bw) when the task blocks.
+ * Instead, we have to wait for the so called "0-lag time".
+ *
+ * If a task blocks before the "0-lag time", a timer (the inactive
+ * timer) is armed, and running_bw is decreased when the timer
+ * fires.
+ *
+ * If the task wakes up again before the inactive timer fires,
+ * the timer is cancelled, whereas if the task wakes up after the
+ * inactive timer fired (and running_bw has been decreased) the
+ * task's utilization has to be added to running_bw again.
+ * A flag in the deadline scheduling entity (dl_non_contending)
+ * is used to avoid race conditions between the inactive timer handler
+ * and task wakeups.
+ *
+ * The following diagram shows how running_bw is updated. A task is
+ * "ACTIVE" when its utilization contributes to running_bw; an
+ * "ACTIVE contending" task is in the TASK_RUNNING state, while an
+ * "ACTIVE non contending" task is a blocked task for which the "0-lag time"
+ * has not passed yet. An "INACTIVE" task is a task for which the "0-lag"
+ * time already passed, which does not contribute to running_bw anymore.
+ * +------------------+
+ * wakeup | ACTIVE |
+ * +------------------>+ contending |
+ * | add_running_bw | |
+ * | +----+------+------+
+ * | | ^
+ * | dequeue | |
+ * +--------+-------+ | |
+ * | | t >= 0-lag | | wakeup
+ * | INACTIVE |<---------------+ |
+ * | | sub_running_bw | |
+ * +--------+-------+ | |
+ * ^ | |
+ * | t < 0-lag | |
+ * | | |
+ * | V |
+ * | +----+------+------+
+ * | sub_running_bw | ACTIVE |
+ * +-------------------+ |
+ * inactive timer | non contending |
+ * fired +------------------+
+ *
+ * The task_non_contending() function is invoked when a task
+ * blocks, and checks if the 0-lag time already passed or
+ * not (in the first case, it directly updates running_bw;
+ * in the second case, it arms the inactive timer).
+ *
+ * The task_contending() function is invoked when a task wakes
+ * up, and checks if the task is still in the "ACTIVE non contending"
+ * state or not (in the second case, it updates running_bw).
+ */
+static void task_non_contending(struct task_struct *p)
+{
+ struct sched_dl_entity *dl_se = &p->dl;
+ struct hrtimer *timer = &dl_se->inactive_timer;
+ struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
+ struct rq *rq = rq_of_dl_rq(dl_rq);
+ s64 zerolag_time;
+
+ /*
+ * If this is a non-deadline task that has been boosted,
+ * do nothing
+ */
+ if (dl_se->dl_runtime == 0)
+ return;
+
+ WARN_ON(hrtimer_active(&dl_se->inactive_timer));
+ WARN_ON(dl_se->dl_non_contending);
+
+ zerolag_time = dl_se->deadline -
+ div64_long((dl_se->runtime * dl_se->dl_period),
+ dl_se->dl_runtime);
+
+ /*
+ * Using relative times instead of the absolute "0-lag time"
+ * allows to simplify the code
+ */
+ zerolag_time -= rq_clock(rq);
+
+ /*
+ * If the "0-lag time" already passed, decrease the active
+ * utilization now, instead of starting a timer
+ */
+ if (zerolag_time < 0) {
+ if (dl_task(p))
+ sub_running_bw(dl_se->dl_bw, dl_rq);
+ if (!dl_task(p) || p->state == TASK_DEAD) {
+ struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
+
+ if (p->state == TASK_DEAD)
+ sub_rq_bw(p->dl.dl_bw, &rq->dl);
+ raw_spin_lock(&dl_b->lock);
+ __dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
+ __dl_clear_params(p);
+ raw_spin_unlock(&dl_b->lock);
+ }
+
+ return;
+ }
+
+ dl_se->dl_non_contending = 1;
+ get_task_struct(p);
+ hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL);
+}
+
+static void task_contending(struct sched_dl_entity *dl_se, int flags)
+{
+ struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
+
+ /*
+ * If this is a non-deadline task that has been boosted,
+ * do nothing
+ */
+ if (dl_se->dl_runtime == 0)
+ return;
+
+ if (flags & ENQUEUE_MIGRATED)
+ add_rq_bw(dl_se->dl_bw, dl_rq);
+
+ if (dl_se->dl_non_contending) {
+ dl_se->dl_non_contending = 0;
+ /*
+ * If the timer handler is currently running and the
+ * timer cannot be cancelled, inactive_task_timer()
+ * will see that dl_not_contending is not set, and
+ * will not touch the rq's active utilization,
+ * so we are still safe.
+ */
+ if (hrtimer_try_to_cancel(&dl_se->inactive_timer) == 1)
+ put_task_struct(dl_task_of(dl_se));
+ } else {
+ /*
+ * Since "dl_non_contending" is not set, the
+ * task's utilization has already been removed from
+ * active utilization (either when the task blocked,
+ * when the "inactive timer" fired).
+ * So, add it back.
+ */
+ add_running_bw(dl_se->dl_bw, dl_rq);
+ }
+}
+
static inline int is_leftmost(struct task_struct *p, struct dl_rq *dl_rq)
{
struct sched_dl_entity *dl_se = &p->dl;
@@ -83,6 +332,10 @@ void init_dl_rq(struct dl_rq *dl_rq)
#else
init_dl_bw(&dl_rq->dl_bw);
#endif
+
+ dl_rq->running_bw = 0;
+ dl_rq->this_bw = 0;
+ init_dl_rq_bw_ratio(dl_rq);
}
#ifdef CONFIG_SMP
@@ -484,13 +737,84 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
}
/*
- * When a -deadline entity is queued back on the runqueue, its runtime and
- * deadline might need updating.
+ * Revised wakeup rule [1]: For self-suspending tasks, rather then
+ * re-initializing task's runtime and deadline, the revised wakeup
+ * rule adjusts the task's runtime to avoid the task to overrun its
+ * density.
+ *
+ * Reasoning: a task may overrun the density if:
+ * runtime / (deadline - t) > dl_runtime / dl_deadline
+ *
+ * Therefore, runtime can be adjusted to:
+ * runtime = (dl_runtime / dl_deadline) * (deadline - t)
+ *
+ * In such way that runtime will be equal to the maximum density
+ * the task can use without breaking any rule.
+ *
+ * [1] Luca Abeni, Giuseppe Lipari, and Juri Lelli. 2015. Constant
+ * bandwidth server revisited. SIGBED Rev. 11, 4 (January 2015), 19-24.
+ */
+static void
+update_dl_revised_wakeup(struct sched_dl_entity *dl_se, struct rq *rq)
+{
+ u64 laxity = dl_se->deadline - rq_clock(rq);
+
+ /*
+ * If the task has deadline < period, and the deadline is in the past,
+ * it should already be throttled before this check.
+ *
+ * See update_dl_entity() comments for further details.
+ */
+ WARN_ON(dl_time_before(dl_se->deadline, rq_clock(rq)));
+
+ dl_se->runtime = (dl_se->dl_density * laxity) >> BW_SHIFT;
+}
+
+/*
+ * Regarding the deadline, a task with implicit deadline has a relative
+ * deadline == relative period. A task with constrained deadline has a
+ * relative deadline <= relative period.
+ *
+ * We support constrained deadline tasks. However, there are some restrictions
+ * applied only for tasks which do not have an implicit deadline. See
+ * update_dl_entity() to know more about such restrictions.
+ *
+ * The dl_is_implicit() returns true if the task has an implicit deadline.
+ */
+static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
+{
+ return dl_se->dl_deadline == dl_se->dl_period;
+}
+
+/*
+ * When a deadline entity is placed in the runqueue, its runtime and deadline
+ * might need to be updated. This is done by a CBS wake up rule. There are two
+ * different rules: 1) the original CBS; and 2) the Revisited CBS.
+ *
+ * When the task is starting a new period, the Original CBS is used. In this
+ * case, the runtime is replenished and a new absolute deadline is set.
+ *
+ * When a task is queued before the begin of the next period, using the
+ * remaining runtime and deadline could make the entity to overflow, see
+ * dl_entity_overflow() to find more about runtime overflow. When such case
+ * is detected, the runtime and deadline need to be updated.
+ *
+ * If the task has an implicit deadline, i.e., deadline == period, the Original
+ * CBS is applied. the runtime is replenished and a new absolute deadline is
+ * set, as in the previous cases.
+ *
+ * However, the Original CBS does not work properly for tasks with
+ * deadline < period, which are said to have a constrained deadline. By
+ * applying the Original CBS, a constrained deadline task would be able to run
+ * runtime/deadline in a period. With deadline < period, the task would
+ * overrun the runtime/period allowed bandwidth, breaking the admission test.
*
- * The policy here is that we update the deadline of the entity only if:
- * - the current deadline is in the past,
- * - using the remaining runtime with the current deadline would make
- * the entity exceed its bandwidth.
+ * In order to prevent this misbehave, the Revisited CBS is used for
+ * constrained deadline tasks when a runtime overflow is detected. In the
+ * Revisited CBS, rather than replenishing & setting a new absolute deadline,
+ * the remaining runtime of the task is reduced to avoid runtime overflow.
+ * Please refer to the comments update_dl_revised_wakeup() function to find
+ * more about the Revised CBS rule.
*/
static void update_dl_entity(struct sched_dl_entity *dl_se,
struct sched_dl_entity *pi_se)
@@ -500,6 +824,14 @@ static void update_dl_entity(struct sched_dl_entity *dl_se,
if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
+
+ if (unlikely(!dl_is_implicit(dl_se) &&
+ !dl_time_before(dl_se->deadline, rq_clock(rq)) &&
+ !dl_se->dl_boosted)){
+ update_dl_revised_wakeup(dl_se, rq);
+ return;
+ }
+
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
dl_se->runtime = pi_se->dl_runtime;
}
@@ -593,10 +925,8 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
* The task might have changed its scheduling policy to something
* different than SCHED_DEADLINE (through switched_from_dl()).
*/
- if (!dl_task(p)) {
- __dl_clear_params(p);
+ if (!dl_task(p))
goto unlock;
- }
/*
* The task might have been boosted by someone else and might be in the
@@ -723,6 +1053,8 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
if (unlikely(dl_se->dl_boosted || !start_dl_timer(p)))
return;
dl_se->dl_throttled = 1;
+ if (dl_se->runtime > 0)
+ dl_se->runtime = 0;
}
}
@@ -735,6 +1067,47 @@ int dl_runtime_exceeded(struct sched_dl_entity *dl_se)
extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
/*
+ * This function implements the GRUB accounting rule:
+ * according to the GRUB reclaiming algorithm, the runtime is
+ * not decreased as "dq = -dt", but as
+ * "dq = -max{u / Umax, (1 - Uinact - Uextra)} dt",
+ * where u is the utilization of the task, Umax is the maximum reclaimable
+ * utilization, Uinact is the (per-runqueue) inactive utilization, computed
+ * as the difference between the "total runqueue utilization" and the
+ * runqueue active utilization, and Uextra is the (per runqueue) extra
+ * reclaimable utilization.
+ * Since rq->dl.running_bw and rq->dl.this_bw contain utilizations
+ * multiplied by 2^BW_SHIFT, the result has to be shifted right by
+ * BW_SHIFT.
+ * Since rq->dl.bw_ratio contains 1 / Umax multipled by 2^RATIO_SHIFT,
+ * dl_bw is multiped by rq->dl.bw_ratio and shifted right by RATIO_SHIFT.
+ * Since delta is a 64 bit variable, to have an overflow its value
+ * should be larger than 2^(64 - 20 - 8), which is more than 64 seconds.
+ * So, overflow is not an issue here.
+ */
+u64 grub_reclaim(u64 delta, struct rq *rq, struct sched_dl_entity *dl_se)
+{
+ u64 u_inact = rq->dl.this_bw - rq->dl.running_bw; /* Utot - Uact */
+ u64 u_act;
+ u64 u_act_min = (dl_se->dl_bw * rq->dl.bw_ratio) >> RATIO_SHIFT;
+
+ /*
+ * Instead of computing max{u * bw_ratio, (1 - u_inact - u_extra)},
+ * we compare u_inact + rq->dl.extra_bw with
+ * 1 - (u * rq->dl.bw_ratio >> RATIO_SHIFT), because
+ * u_inact + rq->dl.extra_bw can be larger than
+ * 1 * (so, 1 - u_inact - rq->dl.extra_bw would be negative
+ * leading to wrong results)
+ */
+ if (u_inact + rq->dl.extra_bw > BW_UNIT - u_act_min)
+ u_act = u_act_min;
+ else
+ u_act = BW_UNIT - u_inact - rq->dl.extra_bw;
+
+ return (delta * u_act) >> BW_SHIFT;
+}
+
+/*
* Update the current task's runtime statistics (provided it is still
* a -deadline task and has not been removed from the dl_rq).
*/
@@ -776,6 +1149,8 @@ static void update_curr_dl(struct rq *rq)
sched_rt_avg_update(rq, delta_exec);
+ if (unlikely(dl_se->flags & SCHED_FLAG_RECLAIM))
+ delta_exec = grub_reclaim(delta_exec, rq, &curr->dl);
dl_se->runtime -= delta_exec;
throttle:
@@ -815,6 +1190,56 @@ throttle:
}
}
+static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer)
+{
+ struct sched_dl_entity *dl_se = container_of(timer,
+ struct sched_dl_entity,
+ inactive_timer);
+ struct task_struct *p = dl_task_of(dl_se);
+ struct rq_flags rf;
+ struct rq *rq;
+
+ rq = task_rq_lock(p, &rf);
+
+ if (!dl_task(p) || p->state == TASK_DEAD) {
+ struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
+
+ if (p->state == TASK_DEAD && dl_se->dl_non_contending) {
+ sub_running_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl));
+ sub_rq_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl));
+ dl_se->dl_non_contending = 0;
+ }
+
+ raw_spin_lock(&dl_b->lock);
+ __dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
+ raw_spin_unlock(&dl_b->lock);
+ __dl_clear_params(p);
+
+ goto unlock;
+ }
+ if (dl_se->dl_non_contending == 0)
+ goto unlock;
+
+ sched_clock_tick();
+ update_rq_clock(rq);
+
+ sub_running_bw(dl_se->dl_bw, &rq->dl);
+ dl_se->dl_non_contending = 0;
+unlock:
+ task_rq_unlock(rq, p, &rf);
+ put_task_struct(p);
+
+ return HRTIMER_NORESTART;
+}
+
+void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se)
+{
+ struct hrtimer *timer = &dl_se->inactive_timer;
+
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ timer->function = inactive_task_timer;
+}
+
#ifdef CONFIG_SMP
static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
@@ -946,10 +1371,12 @@ 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 (flags & ENQUEUE_WAKEUP)
+ if (flags & ENQUEUE_WAKEUP) {
+ task_contending(dl_se, flags);
update_dl_entity(dl_se, pi_se);
- else if (flags & ENQUEUE_REPLENISH)
+ } else if (flags & ENQUEUE_REPLENISH) {
replenish_dl_entity(dl_se, pi_se);
+ }
__enqueue_dl_entity(dl_se);
}
@@ -959,11 +1386,6 @@ static void dequeue_dl_entity(struct sched_dl_entity *dl_se)
__dequeue_dl_entity(dl_se);
}
-static inline bool dl_is_constrained(struct sched_dl_entity *dl_se)
-{
- return dl_se->dl_deadline < dl_se->dl_period;
-}
-
static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
{
struct task_struct *pi_task = rt_mutex_get_top_task(p);
@@ -995,17 +1417,32 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
* If that is the case, the task will be throttled and
* the replenishment timer will be set to the next period.
*/
- if (!p->dl.dl_throttled && dl_is_constrained(&p->dl))
+ if (!p->dl.dl_throttled && !dl_is_implicit(&p->dl))
dl_check_constrained_dl(&p->dl);
+ if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & ENQUEUE_RESTORE) {
+ add_rq_bw(p->dl.dl_bw, &rq->dl);
+ add_running_bw(p->dl.dl_bw, &rq->dl);
+ }
+
/*
- * If p is throttled, we do nothing. In fact, if it exhausted
+ * If p is throttled, we do not enqueue it. In fact, if it exhausted
* its budget it needs a replenishment and, since it now is on
* its rq, the bandwidth timer callback (which clearly has not
* run yet) will take care of this.
+ * However, the active utilization does not depend on the fact
+ * that the task is on the runqueue or not (but depends on the
+ * task's state - in GRUB parlance, "inactive" vs "active contending").
+ * In other words, even if a task is throttled its utilization must
+ * be counted in the active utilization; hence, we need to call
+ * add_running_bw().
*/
- if (p->dl.dl_throttled && !(flags & ENQUEUE_REPLENISH))
+ if (p->dl.dl_throttled && !(flags & ENQUEUE_REPLENISH)) {
+ if (flags & ENQUEUE_WAKEUP)
+ task_contending(&p->dl, flags);
+
return;
+ }
enqueue_dl_entity(&p->dl, pi_se, flags);
@@ -1023,6 +1460,23 @@ static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags)
{
update_curr_dl(rq);
__dequeue_task_dl(rq, p, flags);
+
+ if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & DEQUEUE_SAVE) {
+ sub_running_bw(p->dl.dl_bw, &rq->dl);
+ sub_rq_bw(p->dl.dl_bw, &rq->dl);
+ }
+
+ /*
+ * This check allows to start the inactive timer (or to immediately
+ * decrease the active utilization, if needed) in two cases:
+ * when the task blocks and when it is terminating
+ * (p->state == TASK_DEAD). We can handle the two cases in the same
+ * way, because from GRUB's point of view the same thing is happening
+ * (the task moves from "active contending" to "active non contending"
+ * or "inactive")
+ */
+ if (flags & DEQUEUE_SLEEP)
+ task_non_contending(p);
}
/*
@@ -1100,6 +1554,37 @@ out:
return cpu;
}
+static void migrate_task_rq_dl(struct task_struct *p)
+{
+ struct rq *rq;
+
+ if (p->state != TASK_WAKING)
+ return;
+
+ rq = task_rq(p);
+ /*
+ * Since p->state == TASK_WAKING, set_task_cpu() has been called
+ * from try_to_wake_up(). Hence, p->pi_lock is locked, but
+ * rq->lock is not... So, lock it
+ */
+ raw_spin_lock(&rq->lock);
+ if (p->dl.dl_non_contending) {
+ sub_running_bw(p->dl.dl_bw, &rq->dl);
+ p->dl.dl_non_contending = 0;
+ /*
+ * If the timer handler is currently running and the
+ * timer cannot be cancelled, inactive_task_timer()
+ * will see that dl_not_contending is not set, and
+ * will not touch the rq's active utilization,
+ * so we are still safe.
+ */
+ if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1)
+ put_task_struct(p);
+ }
+ sub_rq_bw(p->dl.dl_bw, &rq->dl);
+ raw_spin_unlock(&rq->lock);
+}
+
static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
{
/*
@@ -1255,19 +1740,6 @@ static void task_fork_dl(struct task_struct *p)
*/
}
-static void task_dead_dl(struct task_struct *p)
-{
- struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
-
- /*
- * Since we are TASK_DEAD we won't slip out of the domain!
- */
- raw_spin_lock_irq(&dl_b->lock);
- /* XXX we should retain the bw until 0-lag */
- dl_b->total_bw -= p->dl.dl_bw;
- raw_spin_unlock_irq(&dl_b->lock);
-}
-
static void set_curr_task_dl(struct rq *rq)
{
struct task_struct *p = rq->curr;
@@ -1533,7 +2005,7 @@ retry:
* then possible that next_task has migrated.
*/
task = pick_next_pushable_dl_task(rq);
- if (task_cpu(next_task) == rq->cpu && task == next_task) {
+ if (task == next_task) {
/*
* The task is still there. We don't try
* again, some other cpu will pull it when ready.
@@ -1551,7 +2023,11 @@ retry:
}
deactivate_task(rq, next_task, 0);
+ sub_running_bw(next_task->dl.dl_bw, &rq->dl);
+ sub_rq_bw(next_task->dl.dl_bw, &rq->dl);
set_task_cpu(next_task, later_rq->cpu);
+ add_rq_bw(next_task->dl.dl_bw, &later_rq->dl);
+ add_running_bw(next_task->dl.dl_bw, &later_rq->dl);
activate_task(later_rq, next_task, 0);
ret = 1;
@@ -1639,7 +2115,11 @@ static void pull_dl_task(struct rq *this_rq)
resched = true;
deactivate_task(src_rq, p, 0);
+ sub_running_bw(p->dl.dl_bw, &src_rq->dl);
+ sub_rq_bw(p->dl.dl_bw, &src_rq->dl);
set_task_cpu(p, this_cpu);
+ add_rq_bw(p->dl.dl_bw, &this_rq->dl);
+ add_running_bw(p->dl.dl_bw, &this_rq->dl);
activate_task(this_rq, p, 0);
dmin = p->dl.deadline;
@@ -1695,7 +2175,7 @@ static void set_cpus_allowed_dl(struct task_struct *p,
* until we complete the update.
*/
raw_spin_lock(&src_dl_b->lock);
- __dl_clear(src_dl_b, p->dl.dl_bw);
+ __dl_clear(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
raw_spin_unlock(&src_dl_b->lock);
}
@@ -1737,13 +2217,26 @@ void __init init_sched_dl_class(void)
static void switched_from_dl(struct rq *rq, struct task_struct *p)
{
/*
- * Start the deadline timer; if we switch back to dl before this we'll
- * continue consuming our current CBS slice. If we stay outside of
- * SCHED_DEADLINE until the deadline passes, the timer will reset the
- * task.
+ * task_non_contending() can start the "inactive timer" (if the 0-lag
+ * time is in the future). If the task switches back to dl before
+ * the "inactive timer" fires, it can continue to consume its current
+ * runtime using its current deadline. If it stays outside of
+ * SCHED_DEADLINE until the 0-lag time passes, inactive_task_timer()
+ * will reset the task parameters.
*/
- if (!start_dl_timer(p))
- __dl_clear_params(p);
+ if (task_on_rq_queued(p) && p->dl.dl_runtime)
+ task_non_contending(p);
+
+ if (!task_on_rq_queued(p))
+ sub_rq_bw(p->dl.dl_bw, &rq->dl);
+
+ /*
+ * We cannot use inactive_task_timer() to invoke sub_running_bw()
+ * at the 0-lag time, because the task could have been migrated
+ * while SCHED_OTHER in the meanwhile.
+ */
+ if (p->dl.dl_non_contending)
+ p->dl.dl_non_contending = 0;
/*
* Since this might be the only -deadline task on the rq,
@@ -1762,11 +2255,15 @@ 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 (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1)
+ put_task_struct(p);
/* If p is not queued we will update its parameters at next wakeup. */
- if (!task_on_rq_queued(p))
- return;
+ if (!task_on_rq_queued(p)) {
+ add_rq_bw(p->dl.dl_bw, &rq->dl);
+ return;
+ }
/*
* If p is boosted we already updated its params in
* rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH),
@@ -1836,6 +2333,7 @@ const struct sched_class dl_sched_class = {
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_dl,
+ .migrate_task_rq = migrate_task_rq_dl,
.set_cpus_allowed = set_cpus_allowed_dl,
.rq_online = rq_online_dl,
.rq_offline = rq_offline_dl,
@@ -1845,7 +2343,6 @@ const struct sched_class dl_sched_class = {
.set_curr_task = set_curr_task_dl,
.task_tick = task_tick_dl,
.task_fork = task_fork_dl,
- .task_dead = task_dead_dl,
.prio_changed = prio_changed_dl,
.switched_from = switched_from_dl,
@@ -1854,6 +2351,317 @@ const struct sched_class dl_sched_class = {
.update_curr = update_curr_dl,
};
+int sched_dl_global_validate(void)
+{
+ u64 runtime = global_rt_runtime();
+ u64 period = global_rt_period();
+ u64 new_bw = to_ratio(period, runtime);
+ struct dl_bw *dl_b;
+ int cpu, ret = 0;
+ unsigned long flags;
+
+ /*
+ * Here we want to check the bandwidth not being set to some
+ * value smaller than the currently allocated bandwidth in
+ * any of the root_domains.
+ *
+ * FIXME: Cycling on all the CPUs is overdoing, but simpler than
+ * cycling on root_domains... Discussion on different/better
+ * solutions is welcome!
+ */
+ for_each_possible_cpu(cpu) {
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(cpu);
+
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ if (new_bw < dl_b->total_bw)
+ ret = -EBUSY;
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+
+ rcu_read_unlock_sched();
+
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
+{
+ if (global_rt_runtime() == RUNTIME_INF) {
+ dl_rq->bw_ratio = 1 << RATIO_SHIFT;
+ dl_rq->extra_bw = 1 << BW_SHIFT;
+ } else {
+ dl_rq->bw_ratio = to_ratio(global_rt_runtime(),
+ global_rt_period()) >> (BW_SHIFT - RATIO_SHIFT);
+ dl_rq->extra_bw = to_ratio(global_rt_period(),
+ global_rt_runtime());
+ }
+}
+
+void sched_dl_do_global(void)
+{
+ u64 new_bw = -1;
+ struct dl_bw *dl_b;
+ int cpu;
+ unsigned long flags;
+
+ def_dl_bandwidth.dl_period = global_rt_period();
+ def_dl_bandwidth.dl_runtime = global_rt_runtime();
+
+ if (global_rt_runtime() != RUNTIME_INF)
+ new_bw = to_ratio(global_rt_period(), global_rt_runtime());
+
+ /*
+ * FIXME: As above...
+ */
+ for_each_possible_cpu(cpu) {
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(cpu);
+
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ dl_b->bw = new_bw;
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+
+ rcu_read_unlock_sched();
+ init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl);
+ }
+}
+
+/*
+ * We must be sure that accepting a new task (or allowing changing the
+ * parameters of an existing one) is consistent with the bandwidth
+ * constraints. If yes, this function also accordingly updates the currently
+ * allocated bandwidth to reflect the new situation.
+ *
+ * This function is called while holding p's rq->lock.
+ */
+int sched_dl_overflow(struct task_struct *p, int policy,
+ const struct sched_attr *attr)
+{
+ struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
+ u64 period = attr->sched_period ?: attr->sched_deadline;
+ u64 runtime = attr->sched_runtime;
+ u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
+ int cpus, err = -1;
+
+ /* !deadline task may carry old deadline bandwidth */
+ if (new_bw == p->dl.dl_bw && task_has_dl_policy(p))
+ return 0;
+
+ /*
+ * Either if a task, enters, leave, or stays -deadline but changes
+ * its parameters, we may need to update accordingly the total
+ * allocated bandwidth of the container.
+ */
+ raw_spin_lock(&dl_b->lock);
+ cpus = dl_bw_cpus(task_cpu(p));
+ if (dl_policy(policy) && !task_has_dl_policy(p) &&
+ !__dl_overflow(dl_b, cpus, 0, new_bw)) {
+ if (hrtimer_active(&p->dl.inactive_timer))
+ __dl_clear(dl_b, p->dl.dl_bw, cpus);
+ __dl_add(dl_b, new_bw, cpus);
+ err = 0;
+ } else if (dl_policy(policy) && task_has_dl_policy(p) &&
+ !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
+ /*
+ * XXX this is slightly incorrect: when the task
+ * utilization decreases, we should delay the total
+ * utilization change until the task's 0-lag point.
+ * But this would require to set the task's "inactive
+ * timer" when the task is not inactive.
+ */
+ __dl_clear(dl_b, p->dl.dl_bw, cpus);
+ __dl_add(dl_b, new_bw, cpus);
+ dl_change_utilization(p, new_bw);
+ err = 0;
+ } else if (!dl_policy(policy) && task_has_dl_policy(p)) {
+ /*
+ * Do not decrease the total deadline utilization here,
+ * switched_from_dl() will take care to do it at the correct
+ * (0-lag) time.
+ */
+ err = 0;
+ }
+ raw_spin_unlock(&dl_b->lock);
+
+ return err;
+}
+
+/*
+ * This function initializes the sched_dl_entity of a newly becoming
+ * SCHED_DEADLINE task.
+ *
+ * Only the static values are considered here, the actual runtime and the
+ * absolute deadline will be properly calculated when the task is enqueued
+ * for the first time with its new policy.
+ */
+void __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
+{
+ struct sched_dl_entity *dl_se = &p->dl;
+
+ dl_se->dl_runtime = attr->sched_runtime;
+ dl_se->dl_deadline = attr->sched_deadline;
+ dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
+ dl_se->flags = attr->sched_flags;
+ dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
+ dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);
+}
+
+void __getparam_dl(struct task_struct *p, struct sched_attr *attr)
+{
+ struct sched_dl_entity *dl_se = &p->dl;
+
+ attr->sched_priority = p->rt_priority;
+ attr->sched_runtime = dl_se->dl_runtime;
+ attr->sched_deadline = dl_se->dl_deadline;
+ attr->sched_period = dl_se->dl_period;
+ attr->sched_flags = dl_se->flags;
+}
+
+/*
+ * This function validates the new parameters of a -deadline task.
+ * We ask for the deadline not being zero, and greater or equal
+ * than the runtime, as well as the period of being zero or
+ * greater than deadline. Furthermore, we have to be sure that
+ * user parameters are above the internal resolution of 1us (we
+ * check sched_runtime only since it is always the smaller one) and
+ * below 2^63 ns (we have to check both sched_deadline and
+ * sched_period, as the latter can be zero).
+ */
+bool __checkparam_dl(const struct sched_attr *attr)
+{
+ /* deadline != 0 */
+ if (attr->sched_deadline == 0)
+ return false;
+
+ /*
+ * Since we truncate DL_SCALE bits, make sure we're at least
+ * that big.
+ */
+ if (attr->sched_runtime < (1ULL << DL_SCALE))
+ return false;
+
+ /*
+ * Since we use the MSB for wrap-around and sign issues, make
+ * sure it's not set (mind that period can be equal to zero).
+ */
+ if (attr->sched_deadline & (1ULL << 63) ||
+ attr->sched_period & (1ULL << 63))
+ return false;
+
+ /* runtime <= deadline <= period (if period != 0) */
+ if ((attr->sched_period != 0 &&
+ attr->sched_period < attr->sched_deadline) ||
+ attr->sched_deadline < attr->sched_runtime)
+ return false;
+
+ return true;
+}
+
+/*
+ * This function clears the sched_dl_entity static params.
+ */
+void __dl_clear_params(struct task_struct *p)
+{
+ struct sched_dl_entity *dl_se = &p->dl;
+
+ dl_se->dl_runtime = 0;
+ dl_se->dl_deadline = 0;
+ dl_se->dl_period = 0;
+ dl_se->flags = 0;
+ dl_se->dl_bw = 0;
+ dl_se->dl_density = 0;
+
+ dl_se->dl_throttled = 0;
+ dl_se->dl_yielded = 0;
+ dl_se->dl_non_contending = 0;
+}
+
+bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
+{
+ struct sched_dl_entity *dl_se = &p->dl;
+
+ if (dl_se->dl_runtime != attr->sched_runtime ||
+ dl_se->dl_deadline != attr->sched_deadline ||
+ dl_se->dl_period != attr->sched_period ||
+ dl_se->flags != attr->sched_flags)
+ return true;
+
+ return false;
+}
+
+#ifdef CONFIG_SMP
+int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed)
+{
+ unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,
+ cs_cpus_allowed);
+ struct dl_bw *dl_b;
+ bool overflow;
+ int cpus, ret;
+ unsigned long flags;
+
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(dest_cpu);
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ cpus = dl_bw_cpus(dest_cpu);
+ overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
+ if (overflow)
+ ret = -EBUSY;
+ else {
+ /*
+ * We reserve space for this task in the destination
+ * root_domain, as we can't fail after this point.
+ * We will free resources in the source root_domain
+ * later on (see set_cpus_allowed_dl()).
+ */
+ __dl_add(dl_b, p->dl.dl_bw, cpus);
+ ret = 0;
+ }
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+ rcu_read_unlock_sched();
+ return ret;
+}
+
+int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,
+ const struct cpumask *trial)
+{
+ int ret = 1, trial_cpus;
+ struct dl_bw *cur_dl_b;
+ unsigned long flags;
+
+ rcu_read_lock_sched();
+ cur_dl_b = dl_bw_of(cpumask_any(cur));
+ trial_cpus = cpumask_weight(trial);
+
+ raw_spin_lock_irqsave(&cur_dl_b->lock, flags);
+ if (cur_dl_b->bw != -1 &&
+ cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw)
+ ret = 0;
+ raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);
+ rcu_read_unlock_sched();
+ return ret;
+}
+
+bool dl_cpu_busy(unsigned int cpu)
+{
+ unsigned long flags;
+ struct dl_bw *dl_b;
+ bool overflow;
+ int cpus;
+
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(cpu);
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ cpus = dl_bw_cpus(cpu);
+ overflow = __dl_overflow(dl_b, cpus, 0, 0);
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+ rcu_read_unlock_sched();
+ return overflow;
+}
+#endif
+
#ifdef CONFIG_SCHED_DEBUG
extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 38f019324f1a..4fa66de52bd6 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -552,15 +552,21 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
#define P(x) \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
+#define PU(x) \
+ SEQ_printf(m, " .%-30s: %lu\n", #x, (unsigned long)(rt_rq->x))
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
- P(rt_nr_running);
+ PU(rt_nr_running);
+#ifdef CONFIG_SMP
+ PU(rt_nr_migratory);
+#endif
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
#undef PN
+#undef PU
#undef P
}
@@ -569,14 +575,21 @@ 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);
+
+#define PU(x) \
+ SEQ_printf(m, " .%-30s: %lu\n", #x, (unsigned long)(dl_rq->x))
+
+ PU(dl_nr_running);
#ifdef CONFIG_SMP
+ PU(dl_nr_migratory);
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);
+
+#undef PU
}
extern __read_mostly int sched_clock_running;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c77e4b1d51c0..008c514dc241 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -369,8 +369,9 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
}
/* Iterate thr' all leaf cfs_rq's on a runqueue */
-#define for_each_leaf_cfs_rq(rq, cfs_rq) \
- list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
+#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \
+ list_for_each_entry_safe(cfs_rq, pos, &rq->leaf_cfs_rq_list, \
+ leaf_cfs_rq_list)
/* Do the two (enqueued) entities belong to the same group ? */
static inline struct cfs_rq *
@@ -463,8 +464,8 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
}
-#define for_each_leaf_cfs_rq(rq, cfs_rq) \
- for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
+#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \
+ for (cfs_rq = &rq->cfs, pos = NULL; cfs_rq; cfs_rq = pos)
static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
@@ -1381,7 +1382,6 @@ static unsigned long weighted_cpuload(const int cpu);
static unsigned long source_load(int cpu, int type);
static unsigned long target_load(int cpu, int type);
static unsigned long capacity_of(int cpu);
-static long effective_load(struct task_group *tg, int cpu, long wl, long wg);
/* Cached statistics for all CPUs within a node */
struct numa_stats {
@@ -2469,7 +2469,8 @@ void task_numa_work(struct callback_head *work)
return;
- down_read(&mm->mmap_sem);
+ if (!down_read_trylock(&mm->mmap_sem))
+ return;
vma = find_vma(mm, start);
if (!vma) {
reset_ptenuma_scan(p);
@@ -2584,6 +2585,60 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
}
}
}
+
+/*
+ * Can a task be moved from prev_cpu to this_cpu without causing a load
+ * imbalance that would trigger the load balancer?
+ */
+static inline bool numa_wake_affine(struct sched_domain *sd,
+ struct task_struct *p, int this_cpu,
+ int prev_cpu, int sync)
+{
+ struct numa_stats prev_load, this_load;
+ s64 this_eff_load, prev_eff_load;
+
+ update_numa_stats(&prev_load, cpu_to_node(prev_cpu));
+ update_numa_stats(&this_load, cpu_to_node(this_cpu));
+
+ /*
+ * If sync wakeup then subtract the (maximum possible)
+ * effect of the currently running task from the load
+ * of the current CPU:
+ */
+ if (sync) {
+ unsigned long current_load = task_h_load(current);
+
+ if (this_load.load > current_load)
+ this_load.load -= current_load;
+ else
+ this_load.load = 0;
+ }
+
+ /*
+ * In low-load situations, where this_cpu's node is idle due to the
+ * sync cause above having dropped this_load.load to 0, move the task.
+ * Moving to an idle socket will not create a bad imbalance.
+ *
+ * Otherwise check if the nodes are near enough in load to allow this
+ * task to be woken on this_cpu's node.
+ */
+ if (this_load.load > 0) {
+ unsigned long task_load = task_h_load(p);
+
+ this_eff_load = 100;
+ this_eff_load *= prev_load.compute_capacity;
+
+ prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
+ prev_eff_load *= this_load.compute_capacity;
+
+ this_eff_load *= this_load.load + task_load;
+ prev_eff_load *= prev_load.load - task_load;
+
+ return this_eff_load <= prev_eff_load;
+ }
+
+ return true;
+}
#else
static void task_tick_numa(struct rq *rq, struct task_struct *curr)
{
@@ -2596,6 +2651,15 @@ static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p)
static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
{
}
+
+#ifdef CONFIG_SMP
+static inline bool numa_wake_affine(struct sched_domain *sd,
+ struct task_struct *p, int this_cpu,
+ int prev_cpu, int sync)
+{
+ return true;
+}
+#endif /* !SMP */
#endif /* CONFIG_NUMA_BALANCING */
static void
@@ -2916,12 +2980,12 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
/*
* Step 2: update *_avg.
*/
- sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX);
+ sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);
if (cfs_rq) {
cfs_rq->runnable_load_avg =
- div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX);
+ div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);
}
- sa->util_avg = sa->util_sum / LOAD_AVG_MAX;
+ sa->util_avg = sa->util_sum / (LOAD_AVG_MAX - 1024 + sa->period_contrib);
return 1;
}
@@ -2982,8 +3046,7 @@ __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq)
* differential update where we store the last value we propagated. This in
* turn allows skipping updates if the differential is 'small'.
*
- * Updating tg's load_avg is necessary before update_cfs_share() (which is
- * done) and effective_load() (which is not done because it is too costly).
+ * Updating tg's load_avg is necessary before update_cfs_share().
*/
static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
{
@@ -4642,24 +4705,43 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
hrtimer_cancel(&cfs_b->slack_timer);
}
+/*
+ * Both these cpu hotplug callbacks race against unregister_fair_sched_group()
+ *
+ * The race is harmless, since modifying bandwidth settings of unhooked group
+ * bits doesn't do much.
+ */
+
+/* cpu online calback */
static void __maybe_unused update_runtime_enabled(struct rq *rq)
{
- struct cfs_rq *cfs_rq;
+ struct task_group *tg;
- for_each_leaf_cfs_rq(rq, cfs_rq) {
- struct cfs_bandwidth *cfs_b = &cfs_rq->tg->cfs_bandwidth;
+ lockdep_assert_held(&rq->lock);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tg, &task_groups, list) {
+ struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
raw_spin_lock(&cfs_b->lock);
cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF;
raw_spin_unlock(&cfs_b->lock);
}
+ rcu_read_unlock();
}
+/* cpu offline callback */
static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
{
- struct cfs_rq *cfs_rq;
+ struct task_group *tg;
+
+ lockdep_assert_held(&rq->lock);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tg, &task_groups, list) {
+ struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
- for_each_leaf_cfs_rq(rq, cfs_rq) {
if (!cfs_rq->runtime_enabled)
continue;
@@ -4677,6 +4759,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
if (cfs_rq_throttled(cfs_rq))
unthrottle_cfs_rq(cfs_rq);
}
+ rcu_read_unlock();
}
#else /* CONFIG_CFS_BANDWIDTH */
@@ -5215,126 +5298,6 @@ static unsigned long cpu_avg_load_per_task(int cpu)
return 0;
}
-#ifdef CONFIG_FAIR_GROUP_SCHED
-/*
- * effective_load() calculates the load change as seen from the root_task_group
- *
- * Adding load to a group doesn't make a group heavier, but can cause movement
- * of group shares between cpus. Assuming the shares were perfectly aligned one
- * can calculate the shift in shares.
- *
- * Calculate the effective load difference if @wl is added (subtracted) to @tg
- * on this @cpu and results in a total addition (subtraction) of @wg to the
- * total group weight.
- *
- * Given a runqueue weight distribution (rw_i) we can compute a shares
- * distribution (s_i) using:
- *
- * s_i = rw_i / \Sum rw_j (1)
- *
- * Suppose we have 4 CPUs and our @tg is a direct child of the root group and
- * has 7 equal weight tasks, distributed as below (rw_i), with the resulting
- * shares distribution (s_i):
- *
- * rw_i = { 2, 4, 1, 0 }
- * s_i = { 2/7, 4/7, 1/7, 0 }
- *
- * As per wake_affine() we're interested in the load of two CPUs (the CPU the
- * task used to run on and the CPU the waker is running on), we need to
- * compute the effect of waking a task on either CPU and, in case of a sync
- * wakeup, compute the effect of the current task going to sleep.
- *
- * So for a change of @wl to the local @cpu with an overall group weight change
- * of @wl we can compute the new shares distribution (s'_i) using:
- *
- * s'_i = (rw_i + @wl) / (@wg + \Sum rw_j) (2)
- *
- * Suppose we're interested in CPUs 0 and 1, and want to compute the load
- * differences in waking a task to CPU 0. The additional task changes the
- * weight and shares distributions like:
- *
- * rw'_i = { 3, 4, 1, 0 }
- * s'_i = { 3/8, 4/8, 1/8, 0 }
- *
- * We can then compute the difference in effective weight by using:
- *
- * dw_i = S * (s'_i - s_i) (3)
- *
- * Where 'S' is the group weight as seen by its parent.
- *
- * Therefore the effective change in loads on CPU 0 would be 5/56 (3/8 - 2/7)
- * times the weight of the group. The effect on CPU 1 would be -4/56 (4/8 -
- * 4/7) times the weight of the group.
- */
-static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
-{
- struct sched_entity *se = tg->se[cpu];
-
- if (!tg->parent) /* the trivial, non-cgroup case */
- return wl;
-
- for_each_sched_entity(se) {
- struct cfs_rq *cfs_rq = se->my_q;
- long W, w = cfs_rq_load_avg(cfs_rq);
-
- tg = cfs_rq->tg;
-
- /*
- * W = @wg + \Sum rw_j
- */
- W = wg + atomic_long_read(&tg->load_avg);
-
- /* Ensure \Sum rw_j >= rw_i */
- W -= cfs_rq->tg_load_avg_contrib;
- W += w;
-
- /*
- * w = rw_i + @wl
- */
- w += wl;
-
- /*
- * wl = S * s'_i; see (2)
- */
- if (W > 0 && w < W)
- wl = (w * (long)scale_load_down(tg->shares)) / W;
- else
- wl = scale_load_down(tg->shares);
-
- /*
- * Per the above, wl is the new se->load.weight value; since
- * those are clipped to [MIN_SHARES, ...) do so now. See
- * calc_cfs_shares().
- */
- if (wl < MIN_SHARES)
- wl = MIN_SHARES;
-
- /*
- * wl = dw_i = S * (s'_i - s_i); see (3)
- */
- wl -= se->avg.load_avg;
-
- /*
- * Recursively apply this logic to all parent groups to compute
- * the final effective load change on the root group. Since
- * only the @tg group gets extra weight, all parent groups can
- * only redistribute existing shares. @wl is the shift in shares
- * resulting from this level per the above.
- */
- wg = 0;
- }
-
- return wl;
-}
-#else
-
-static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
-{
- return wl;
-}
-
-#endif
-
static void record_wakee(struct task_struct *p)
{
/*
@@ -5385,67 +5348,25 @@ static int wake_wide(struct task_struct *p)
static int wake_affine(struct sched_domain *sd, struct task_struct *p,
int prev_cpu, int sync)
{
- s64 this_load, load;
- s64 this_eff_load, prev_eff_load;
- int idx, this_cpu;
- struct task_group *tg;
- unsigned long weight;
- int balanced;
-
- idx = sd->wake_idx;
- this_cpu = smp_processor_id();
- load = source_load(prev_cpu, idx);
- this_load = target_load(this_cpu, idx);
-
- /*
- * If sync wakeup then subtract the (maximum possible)
- * effect of the currently running task from the load
- * of the current CPU:
- */
- if (sync) {
- tg = task_group(current);
- weight = current->se.avg.load_avg;
-
- this_load += effective_load(tg, this_cpu, -weight, -weight);
- load += effective_load(tg, prev_cpu, 0, -weight);
- }
-
- tg = task_group(p);
- weight = p->se.avg.load_avg;
+ int this_cpu = smp_processor_id();
+ bool affine = false;
/*
- * In low-load situations, where prev_cpu is idle and this_cpu is idle
- * due to the sync cause above having dropped this_load to 0, we'll
- * always have an imbalance, but there's really nothing you can do
- * about that, so that's good too.
- *
- * Otherwise check if either cpus are near enough in load to allow this
- * task to be woken on this_cpu.
+ * Common case: CPUs are in the same socket, and select_idle_sibling()
+ * will do its thing regardless of what we return:
*/
- this_eff_load = 100;
- this_eff_load *= capacity_of(prev_cpu);
-
- prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
- prev_eff_load *= capacity_of(this_cpu);
-
- if (this_load > 0) {
- this_eff_load *= this_load +
- effective_load(tg, this_cpu, weight, weight);
-
- prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);
- }
-
- balanced = this_eff_load <= prev_eff_load;
+ if (cpus_share_cache(prev_cpu, this_cpu))
+ affine = true;
+ else
+ affine = numa_wake_affine(sd, p, this_cpu, prev_cpu, sync);
schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts);
+ if (affine) {
+ schedstat_inc(sd->ttwu_move_affine);
+ schedstat_inc(p->se.statistics.nr_wakeups_affine);
+ }
- if (!balanced)
- return 0;
-
- schedstat_inc(sd->ttwu_move_affine);
- schedstat_inc(p->se.statistics.nr_wakeups_affine);
-
- return 1;
+ return affine;
}
static inline int task_util(struct task_struct *p);
@@ -5484,12 +5405,12 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
int i;
/* Skip over this group if it has no CPUs allowed */
- if (!cpumask_intersects(sched_group_cpus(group),
+ if (!cpumask_intersects(sched_group_span(group),
&p->cpus_allowed))
continue;
local_group = cpumask_test_cpu(this_cpu,
- sched_group_cpus(group));
+ sched_group_span(group));
/*
* Tally up the load of all CPUs in the group and find
@@ -5499,7 +5420,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
runnable_load = 0;
max_spare_cap = 0;
- for_each_cpu(i, sched_group_cpus(group)) {
+ for_each_cpu(i, sched_group_span(group)) {
/* Bias balancing toward cpus of our domain */
if (local_group)
load = source_load(i, load_idx);
@@ -5602,10 +5523,10 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
/* Check if we have any choice: */
if (group->group_weight == 1)
- return cpumask_first(sched_group_cpus(group));
+ return cpumask_first(sched_group_span(group));
/* Traverse only the allowed CPUs */
- for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) {
+ for_each_cpu_and(i, sched_group_span(group), &p->cpus_allowed) {
if (idle_cpu(i)) {
struct rq *rq = cpu_rq(i);
struct cpuidle_state *idle = idle_get_state(rq);
@@ -5640,43 +5561,6 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
}
-/*
- * Implement a for_each_cpu() variant that starts the scan at a given cpu
- * (@start), and wraps around.
- *
- * This is used to scan for idle CPUs; such that not all CPUs looking for an
- * idle CPU find the same CPU. The down-side is that tasks tend to cycle
- * through the LLC domain.
- *
- * Especially tbench is found sensitive to this.
- */
-
-static int cpumask_next_wrap(int n, const struct cpumask *mask, int start, int *wrapped)
-{
- int next;
-
-again:
- next = find_next_bit(cpumask_bits(mask), nr_cpumask_bits, n+1);
-
- if (*wrapped) {
- if (next >= start)
- return nr_cpumask_bits;
- } else {
- if (next >= nr_cpumask_bits) {
- *wrapped = 1;
- n = -1;
- goto again;
- }
- }
-
- return next;
-}
-
-#define for_each_cpu_wrap(cpu, mask, start, wrap) \
- for ((wrap) = 0, (cpu) = (start)-1; \
- (cpu) = cpumask_next_wrap((cpu), (mask), (start), &(wrap)), \
- (cpu) < nr_cpumask_bits; )
-
#ifdef CONFIG_SCHED_SMT
static inline void set_idle_cores(int cpu, int val)
@@ -5736,7 +5620,7 @@ unlock:
static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target)
{
struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
- int core, cpu, wrap;
+ int core, cpu;
if (!static_branch_likely(&sched_smt_present))
return -1;
@@ -5746,7 +5630,7 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int
cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed);
- for_each_cpu_wrap(core, cpus, target, wrap) {
+ for_each_cpu_wrap(core, cpus, target) {
bool idle = true;
for_each_cpu(cpu, cpu_smt_mask(core)) {
@@ -5809,27 +5693,38 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd
static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int target)
{
struct sched_domain *this_sd;
- u64 avg_cost, avg_idle = this_rq()->avg_idle;
+ u64 avg_cost, avg_idle;
u64 time, cost;
s64 delta;
- int cpu, wrap;
+ int cpu, nr = INT_MAX;
this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));
if (!this_sd)
return -1;
- avg_cost = this_sd->avg_scan_cost;
-
/*
* Due to large variance we need a large fuzz factor; hackbench in
* particularly is sensitive here.
*/
- if (sched_feat(SIS_AVG_CPU) && (avg_idle / 512) < avg_cost)
+ avg_idle = this_rq()->avg_idle / 512;
+ avg_cost = this_sd->avg_scan_cost + 1;
+
+ if (sched_feat(SIS_AVG_CPU) && avg_idle < avg_cost)
return -1;
+ if (sched_feat(SIS_PROP)) {
+ u64 span_avg = sd->span_weight * avg_idle;
+ if (span_avg > 4*avg_cost)
+ nr = div_u64(span_avg, avg_cost);
+ else
+ nr = 4;
+ }
+
time = local_clock();
- for_each_cpu_wrap(cpu, sched_domain_span(sd), target, wrap) {
+ for_each_cpu_wrap(cpu, sched_domain_span(sd), target) {
+ if (!--nr)
+ return -1;
if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
continue;
if (idle_cpu(cpu))
@@ -6011,11 +5906,15 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
if (affine_sd) {
sd = NULL; /* Prefer wake_affine over balance flags */
- if (cpu != prev_cpu && wake_affine(affine_sd, p, prev_cpu, sync))
+ if (cpu == prev_cpu)
+ goto pick_cpu;
+
+ if (wake_affine(affine_sd, p, prev_cpu, sync))
new_cpu = cpu;
}
if (!sd) {
+ pick_cpu:
if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */
new_cpu = select_idle_sibling(p, prev_cpu, new_cpu);
@@ -6168,8 +6067,11 @@ static void set_last_buddy(struct sched_entity *se)
if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
return;
- for_each_sched_entity(se)
+ for_each_sched_entity(se) {
+ if (SCHED_WARN_ON(!se->on_rq))
+ return;
cfs_rq_of(se)->last = se;
+ }
}
static void set_next_buddy(struct sched_entity *se)
@@ -6177,8 +6079,11 @@ static void set_next_buddy(struct sched_entity *se)
if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
return;
- for_each_sched_entity(se)
+ for_each_sched_entity(se) {
+ if (SCHED_WARN_ON(!se->on_rq))
+ return;
cfs_rq_of(se)->next = se;
+ }
}
static void set_skip_buddy(struct sched_entity *se)
@@ -6686,6 +6591,10 @@ static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
if (dst_nid == p->numa_preferred_nid)
return 0;
+ /* Leaving a core idle is often worse than degrading locality. */
+ if (env->idle != CPU_NOT_IDLE)
+ return -1;
+
if (numa_group) {
src_faults = group_faults(p, src_nid);
dst_faults = group_faults(p, dst_nid);
@@ -6970,10 +6879,28 @@ static void attach_tasks(struct lb_env *env)
}
#ifdef CONFIG_FAIR_GROUP_SCHED
+
+static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
+{
+ if (cfs_rq->load.weight)
+ return false;
+
+ if (cfs_rq->avg.load_sum)
+ return false;
+
+ if (cfs_rq->avg.util_sum)
+ return false;
+
+ if (cfs_rq->runnable_load_sum)
+ return false;
+
+ return true;
+}
+
static void update_blocked_averages(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- struct cfs_rq *cfs_rq;
+ struct cfs_rq *cfs_rq, *pos;
struct rq_flags rf;
rq_lock_irqsave(rq, &rf);
@@ -6983,7 +6910,7 @@ static void update_blocked_averages(int cpu)
* Iterates the task_group tree in a bottom up fashion, see
* list_add_leaf_cfs_rq() for details.
*/
- for_each_leaf_cfs_rq(rq, cfs_rq) {
+ for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) {
struct sched_entity *se;
/* throttled entities do not contribute to load */
@@ -6997,6 +6924,13 @@ static void update_blocked_averages(int cpu)
se = cfs_rq->tg->se[cpu];
if (se && !skip_blocked_update(se))
update_load_avg(se, 0);
+
+ /*
+ * There can be a lot of idle CPU cgroups. Don't let fully
+ * decayed cfs_rqs linger on the list.
+ */
+ if (cfs_rq_is_decayed(cfs_rq))
+ list_del_leaf_cfs_rq(cfs_rq);
}
rq_unlock_irqrestore(rq, &rf);
}
@@ -7229,7 +7163,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
* span the current group.
*/
- for_each_cpu(cpu, sched_group_cpus(sdg)) {
+ for_each_cpu(cpu, sched_group_span(sdg)) {
struct sched_group_capacity *sgc;
struct rq *rq = cpu_rq(cpu);
@@ -7408,7 +7342,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
memset(sgs, 0, sizeof(*sgs));
- for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
+ for_each_cpu_and(i, sched_group_span(group), env->cpus) {
struct rq *rq = cpu_rq(i);
/* Bias balancing toward cpus of our domain */
@@ -7572,7 +7506,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
struct sg_lb_stats *sgs = &tmp_sgs;
int local_group;
- local_group = cpumask_test_cpu(env->dst_cpu, sched_group_cpus(sg));
+ local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(sg));
if (local_group) {
sds->local = sg;
sgs = local;
@@ -7927,7 +7861,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
unsigned long busiest_load = 0, busiest_capacity = 1;
int i;
- for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
+ for_each_cpu_and(i, sched_group_span(group), env->cpus) {
unsigned long capacity, wl;
enum fbq_type rt;
@@ -8033,7 +7967,6 @@ static int active_load_balance_cpu_stop(void *data);
static int should_we_balance(struct lb_env *env)
{
struct sched_group *sg = env->sd->groups;
- struct cpumask *sg_cpus, *sg_mask;
int cpu, balance_cpu = -1;
/*
@@ -8043,11 +7976,9 @@ static int should_we_balance(struct lb_env *env)
if (env->idle == CPU_NEWLY_IDLE)
return 1;
- sg_cpus = sched_group_cpus(sg);
- sg_mask = sched_group_mask(sg);
/* Try to find first idle cpu */
- for_each_cpu_and(cpu, sg_cpus, env->cpus) {
- if (!cpumask_test_cpu(cpu, sg_mask) || !idle_cpu(cpu))
+ for_each_cpu_and(cpu, group_balance_mask(sg), env->cpus) {
+ if (!idle_cpu(cpu))
continue;
balance_cpu = cpu;
@@ -8083,7 +8014,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
.sd = sd,
.dst_cpu = this_cpu,
.dst_rq = this_rq,
- .dst_grpmask = sched_group_cpus(sd->groups),
+ .dst_grpmask = sched_group_span(sd->groups),
.idle = idle,
.loop_break = sched_nr_migrate_break,
.cpus = cpus,
@@ -8659,6 +8590,10 @@ void nohz_balance_enter_idle(int cpu)
if (!cpu_active(cpu))
return;
+ /* Spare idle load balancing on CPUs that don't want to be disturbed: */
+ if (!is_housekeeping_cpu(cpu))
+ return;
+
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
return;
@@ -9523,10 +9458,10 @@ const struct sched_class fair_sched_class = {
#ifdef CONFIG_SCHED_DEBUG
void print_cfs_stats(struct seq_file *m, int cpu)
{
- struct cfs_rq *cfs_rq;
+ struct cfs_rq *cfs_rq, *pos;
rcu_read_lock();
- for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
+ for_each_leaf_cfs_rq_safe(cpu_rq(cpu), cfs_rq, pos)
print_cfs_rq(m, cpu, cfs_rq);
rcu_read_unlock();
}
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 11192e0cb122..d3fb15555291 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -55,6 +55,7 @@ SCHED_FEAT(TTWU_QUEUE, true)
* When doing wakeups, attempt to limit superfluous scans of the LLC domain.
*/
SCHED_FEAT(SIS_AVG_CPU, false)
+SCHED_FEAT(SIS_PROP, true)
/*
* Issue a WARN when we do multiple update_rq_clock() calls
@@ -76,7 +77,6 @@ SCHED_FEAT(WARN_DOUBLE_CLOCK, false)
SCHED_FEAT(RT_PUSH_IPI, true)
#endif
-SCHED_FEAT(FORCE_SD_OVERLAP, false)
SCHED_FEAT(RT_RUNTIME_SHARE, true)
SCHED_FEAT(LB_MIN, false)
SCHED_FEAT(ATTACH_AGE_LOAD, true)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index ef63adce0c9c..6c23e30c0e5c 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -219,6 +219,7 @@ static void do_idle(void)
*/
__current_set_polling();
+ quiet_vmstat();
tick_nohz_idle_enter();
while (!need_resched()) {
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index f15fb2bdbc0d..f14716a3522f 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -117,7 +117,7 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
* load-average relies on per-cpu sampling from the tick, it is affected by
* NO_HZ.
*
- * The basic idea is to fold the nr_active delta into a global idle-delta upon
+ * The basic idea is to fold the nr_active delta into a global NO_HZ-delta upon
* entering NO_HZ state such that we can include this as an 'extra' cpu delta
* when we read the global state.
*
@@ -126,7 +126,7 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
* - When we go NO_HZ idle during the window, we can negate our sample
* contribution, causing under-accounting.
*
- * We avoid this by keeping two idle-delta counters and flipping them
+ * We avoid this by keeping two NO_HZ-delta counters and flipping them
* when the window starts, thus separating old and new NO_HZ load.
*
* The only trick is the slight shift in index flip for read vs write.
@@ -137,22 +137,22 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
* r:0 0 1 1 0 0 1 1 0
* w:0 1 1 0 0 1 1 0 0
*
- * This ensures we'll fold the old idle contribution in this window while
+ * This ensures we'll fold the old NO_HZ contribution in this window while
* accumlating the new one.
*
- * - When we wake up from NO_HZ idle during the window, we push up our
+ * - When we wake up from NO_HZ during the window, we push up our
* contribution, since we effectively move our sample point to a known
* busy state.
*
* This is solved by pushing the window forward, and thus skipping the
- * sample, for this cpu (effectively using the idle-delta for this cpu which
+ * sample, for this cpu (effectively using the NO_HZ-delta for this cpu which
* was in effect at the time the window opened). This also solves the issue
- * of having to deal with a cpu having been in NOHZ idle for multiple
- * LOAD_FREQ intervals.
+ * of having to deal with a cpu having been in NO_HZ for multiple LOAD_FREQ
+ * intervals.
*
* When making the ILB scale, we should try to pull this in as well.
*/
-static atomic_long_t calc_load_idle[2];
+static atomic_long_t calc_load_nohz[2];
static int calc_load_idx;
static inline int calc_load_write_idx(void)
@@ -167,7 +167,7 @@ static inline int calc_load_write_idx(void)
/*
* If the folding window started, make sure we start writing in the
- * next idle-delta.
+ * next NO_HZ-delta.
*/
if (!time_before(jiffies, READ_ONCE(calc_load_update)))
idx++;
@@ -180,24 +180,24 @@ static inline int calc_load_read_idx(void)
return calc_load_idx & 1;
}
-void calc_load_enter_idle(void)
+void calc_load_nohz_start(void)
{
struct rq *this_rq = this_rq();
long delta;
/*
- * We're going into NOHZ mode, if there's any pending delta, fold it
- * into the pending idle delta.
+ * We're going into NO_HZ mode, if there's any pending delta, fold it
+ * into the pending NO_HZ delta.
*/
delta = calc_load_fold_active(this_rq, 0);
if (delta) {
int idx = calc_load_write_idx();
- atomic_long_add(delta, &calc_load_idle[idx]);
+ atomic_long_add(delta, &calc_load_nohz[idx]);
}
}
-void calc_load_exit_idle(void)
+void calc_load_nohz_stop(void)
{
struct rq *this_rq = this_rq();
@@ -217,13 +217,13 @@ void calc_load_exit_idle(void)
this_rq->calc_load_update += LOAD_FREQ;
}
-static long calc_load_fold_idle(void)
+static long calc_load_nohz_fold(void)
{
int idx = calc_load_read_idx();
long delta = 0;
- if (atomic_long_read(&calc_load_idle[idx]))
- delta = atomic_long_xchg(&calc_load_idle[idx], 0);
+ if (atomic_long_read(&calc_load_nohz[idx]))
+ delta = atomic_long_xchg(&calc_load_nohz[idx], 0);
return delta;
}
@@ -299,9 +299,9 @@ calc_load_n(unsigned long load, unsigned long exp,
/*
* NO_HZ can leave us missing all per-cpu ticks calling
- * calc_load_account_active(), but since an idle CPU folds its delta into
- * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
- * in the pending idle delta if our idle period crossed a load cycle boundary.
+ * calc_load_fold_active(), but since a NO_HZ CPU folds its delta into
+ * calc_load_nohz per calc_load_nohz_start(), all we need to do is fold
+ * in the pending NO_HZ delta if our NO_HZ period crossed a load cycle boundary.
*
* Once we've updated the global active value, we need to apply the exponential
* weights adjusted to the number of cycles missed.
@@ -330,7 +330,7 @@ static void calc_global_nohz(void)
}
/*
- * Flip the idle index...
+ * Flip the NO_HZ index...
*
* Make sure we first write the new time then flip the index, so that
* calc_load_write_idx() will see the new time when it reads the new
@@ -341,7 +341,7 @@ static void calc_global_nohz(void)
}
#else /* !CONFIG_NO_HZ_COMMON */
-static inline long calc_load_fold_idle(void) { return 0; }
+static inline long calc_load_nohz_fold(void) { return 0; }
static inline void calc_global_nohz(void) { }
#endif /* CONFIG_NO_HZ_COMMON */
@@ -362,9 +362,9 @@ void calc_global_load(unsigned long ticks)
return;
/*
- * Fold the 'old' idle-delta to include all NO_HZ cpus.
+ * Fold the 'old' NO_HZ-delta to include all NO_HZ cpus.
*/
- delta = calc_load_fold_idle();
+ delta = calc_load_nohz_fold();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
@@ -378,7 +378,8 @@ void calc_global_load(unsigned long ticks)
WRITE_ONCE(calc_load_update, sample_window + LOAD_FREQ);
/*
- * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
+ * In case we went to NO_HZ for multiple LOAD_FREQ intervals
+ * catch up in bulk.
*/
calc_global_nohz();
}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 979b7341008a..45caf937ef90 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -840,6 +840,17 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
struct rq *rq = rq_of_rt_rq(rt_rq);
+ int skip;
+
+ /*
+ * When span == cpu_online_mask, taking each rq->lock
+ * can be time-consuming. Try to avoid it when possible.
+ */
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ skip = !rt_rq->rt_time && !rt_rq->rt_nr_running;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ if (skip)
+ continue;
raw_spin_lock(&rq->lock);
if (rt_rq->rt_time) {
@@ -1819,7 +1830,7 @@ retry:
* pushing.
*/
task = pick_next_pushable_task(rq);
- if (task_cpu(next_task) == rq->cpu && task == next_task) {
+ if (task == next_task) {
/*
* The task hasn't migrated, and is still the next
* eligible task, but we failed to find a run-queue
@@ -2438,6 +2449,316 @@ const struct sched_class rt_sched_class = {
.update_curr = update_curr_rt,
};
+#ifdef CONFIG_RT_GROUP_SCHED
+/*
+ * Ensure that the real time constraints are schedulable.
+ */
+static DEFINE_MUTEX(rt_constraints_mutex);
+
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
+{
+ struct task_struct *g, *p;
+
+ /*
+ * Autogroups do not have RT tasks; see autogroup_create().
+ */
+ if (task_group_is_autogroup(tg))
+ return 0;
+
+ for_each_process_thread(g, p) {
+ if (rt_task(p) && task_group(p) == tg)
+ return 1;
+ }
+
+ return 0;
+}
+
+struct rt_schedulable_data {
+ struct task_group *tg;
+ u64 rt_period;
+ u64 rt_runtime;
+};
+
+static int tg_rt_schedulable(struct task_group *tg, void *data)
+{
+ struct rt_schedulable_data *d = data;
+ struct task_group *child;
+ unsigned long total, sum = 0;
+ u64 period, runtime;
+
+ period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+ runtime = tg->rt_bandwidth.rt_runtime;
+
+ if (tg == d->tg) {
+ period = d->rt_period;
+ runtime = d->rt_runtime;
+ }
+
+ /*
+ * Cannot have more runtime than the period.
+ */
+ if (runtime > period && runtime != RUNTIME_INF)
+ return -EINVAL;
+
+ /*
+ * Ensure we don't starve existing RT tasks.
+ */
+ if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+ return -EBUSY;
+
+ total = to_ratio(period, runtime);
+
+ /*
+ * Nobody can have more than the global setting allows.
+ */
+ if (total > to_ratio(global_rt_period(), global_rt_runtime()))
+ return -EINVAL;
+
+ /*
+ * The sum of our children's runtime should not exceed our own.
+ */
+ list_for_each_entry_rcu(child, &tg->children, siblings) {
+ period = ktime_to_ns(child->rt_bandwidth.rt_period);
+ runtime = child->rt_bandwidth.rt_runtime;
+
+ if (child == d->tg) {
+ period = d->rt_period;
+ runtime = d->rt_runtime;
+ }
+
+ sum += to_ratio(period, runtime);
+ }
+
+ if (sum > total)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
+{
+ int ret;
+
+ struct rt_schedulable_data data = {
+ .tg = tg,
+ .rt_period = period,
+ .rt_runtime = runtime,
+ };
+
+ rcu_read_lock();
+ ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static int tg_set_rt_bandwidth(struct task_group *tg,
+ u64 rt_period, u64 rt_runtime)
+{
+ int i, err = 0;
+
+ /*
+ * Disallowing the root group RT runtime is BAD, it would disallow the
+ * kernel creating (and or operating) RT threads.
+ */
+ if (tg == &root_task_group && rt_runtime == 0)
+ return -EINVAL;
+
+ /* No period doesn't make any sense. */
+ if (rt_period == 0)
+ return -EINVAL;
+
+ mutex_lock(&rt_constraints_mutex);
+ read_lock(&tasklist_lock);
+ err = __rt_schedulable(tg, rt_period, rt_runtime);
+ if (err)
+ goto unlock;
+
+ raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
+ tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
+ tg->rt_bandwidth.rt_runtime = rt_runtime;
+
+ for_each_possible_cpu(i) {
+ struct rt_rq *rt_rq = tg->rt_rq[i];
+
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ rt_rq->rt_runtime = rt_runtime;
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ }
+ raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
+unlock:
+ read_unlock(&tasklist_lock);
+ mutex_unlock(&rt_constraints_mutex);
+
+ return err;
+}
+
+int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
+{
+ u64 rt_runtime, rt_period;
+
+ rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+ rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
+ if (rt_runtime_us < 0)
+ rt_runtime = RUNTIME_INF;
+
+ return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
+}
+
+long sched_group_rt_runtime(struct task_group *tg)
+{
+ u64 rt_runtime_us;
+
+ if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
+ return -1;
+
+ rt_runtime_us = tg->rt_bandwidth.rt_runtime;
+ do_div(rt_runtime_us, NSEC_PER_USEC);
+ return rt_runtime_us;
+}
+
+int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us)
+{
+ u64 rt_runtime, rt_period;
+
+ rt_period = rt_period_us * NSEC_PER_USEC;
+ rt_runtime = tg->rt_bandwidth.rt_runtime;
+
+ return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
+}
+
+long sched_group_rt_period(struct task_group *tg)
+{
+ u64 rt_period_us;
+
+ rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
+ do_div(rt_period_us, NSEC_PER_USEC);
+ return rt_period_us;
+}
+
+static int sched_rt_global_constraints(void)
+{
+ int ret = 0;
+
+ mutex_lock(&rt_constraints_mutex);
+ read_lock(&tasklist_lock);
+ ret = __rt_schedulable(NULL, 0, 0);
+ read_unlock(&tasklist_lock);
+ mutex_unlock(&rt_constraints_mutex);
+
+ return ret;
+}
+
+int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
+{
+ /* Don't accept realtime tasks when there is no way for them to run */
+ if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
+ return 0;
+
+ return 1;
+}
+
+#else /* !CONFIG_RT_GROUP_SCHED */
+static int sched_rt_global_constraints(void)
+{
+ unsigned long flags;
+ int i;
+
+ raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
+ for_each_possible_cpu(i) {
+ struct rt_rq *rt_rq = &cpu_rq(i)->rt;
+
+ raw_spin_lock(&rt_rq->rt_runtime_lock);
+ rt_rq->rt_runtime = global_rt_runtime();
+ raw_spin_unlock(&rt_rq->rt_runtime_lock);
+ }
+ raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
+
+ return 0;
+}
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+static int sched_rt_global_validate(void)
+{
+ if (sysctl_sched_rt_period <= 0)
+ return -EINVAL;
+
+ if ((sysctl_sched_rt_runtime != RUNTIME_INF) &&
+ (sysctl_sched_rt_runtime > sysctl_sched_rt_period))
+ return -EINVAL;
+
+ return 0;
+}
+
+static void sched_rt_do_global(void)
+{
+ def_rt_bandwidth.rt_runtime = global_rt_runtime();
+ def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period());
+}
+
+int sched_rt_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int old_period, old_runtime;
+ static DEFINE_MUTEX(mutex);
+ int ret;
+
+ mutex_lock(&mutex);
+ old_period = sysctl_sched_rt_period;
+ old_runtime = sysctl_sched_rt_runtime;
+
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+ if (!ret && write) {
+ ret = sched_rt_global_validate();
+ if (ret)
+ goto undo;
+
+ ret = sched_dl_global_validate();
+ if (ret)
+ goto undo;
+
+ ret = sched_rt_global_constraints();
+ if (ret)
+ goto undo;
+
+ sched_rt_do_global();
+ sched_dl_do_global();
+ }
+ if (0) {
+undo:
+ sysctl_sched_rt_period = old_period;
+ sysctl_sched_rt_runtime = old_runtime;
+ }
+ mutex_unlock(&mutex);
+
+ return ret;
+}
+
+int sched_rr_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret;
+ static DEFINE_MUTEX(mutex);
+
+ mutex_lock(&mutex);
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+ /*
+ * Make sure that internally we keep jiffies.
+ * Also, writing zero resets the timeslice to default:
+ */
+ if (!ret && write) {
+ sched_rr_timeslice =
+ sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE :
+ msecs_to_jiffies(sysctl_sched_rr_timeslice);
+ }
+ mutex_unlock(&mutex);
+ return ret;
+}
+
#ifdef CONFIG_SCHED_DEBUG
extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 6dda2aab731e..eeef1a3086d1 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -39,9 +39,9 @@
#include "cpuacct.h"
#ifdef CONFIG_SCHED_DEBUG
-#define SCHED_WARN_ON(x) WARN_ONCE(x, #x)
+# define SCHED_WARN_ON(x) WARN_ONCE(x, #x)
#else
-#define SCHED_WARN_ON(x) ((void)(x))
+# define SCHED_WARN_ON(x) ({ (void)(x), 0; })
#endif
struct rq;
@@ -218,23 +218,25 @@ static inline int dl_bandwidth_enabled(void)
return sysctl_sched_rt_runtime >= 0;
}
-extern struct dl_bw *dl_bw_of(int i);
-
struct dl_bw {
raw_spinlock_t lock;
u64 bw, total_bw;
};
+static inline void __dl_update(struct dl_bw *dl_b, s64 bw);
+
static inline
-void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
+void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
{
dl_b->total_bw -= tsk_bw;
+ __dl_update(dl_b, (s32)tsk_bw / cpus);
}
static inline
-void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
+void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
{
dl_b->total_bw += tsk_bw;
+ __dl_update(dl_b, -((s32)tsk_bw / cpus));
}
static inline
@@ -244,7 +246,22 @@ bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
}
+void dl_change_utilization(struct task_struct *p, u64 new_bw);
extern void init_dl_bw(struct dl_bw *dl_b);
+extern int sched_dl_global_validate(void);
+extern void sched_dl_do_global(void);
+extern int sched_dl_overflow(struct task_struct *p, int policy,
+ const struct sched_attr *attr);
+extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
+extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
+extern bool __checkparam_dl(const struct sched_attr *attr);
+extern void __dl_clear_params(struct task_struct *p);
+extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
+extern int dl_task_can_attach(struct task_struct *p,
+ const struct cpumask *cs_cpus_allowed);
+extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,
+ const struct cpumask *trial);
+extern bool dl_cpu_busy(unsigned int cpu);
#ifdef CONFIG_CGROUP_SCHED
@@ -366,6 +383,11 @@ extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent
extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
struct sched_rt_entity *rt_se, int cpu,
struct sched_rt_entity *parent);
+extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
+extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
+extern long sched_group_rt_runtime(struct task_group *tg);
+extern long sched_group_rt_period(struct task_group *tg);
+extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
extern struct task_group *sched_create_group(struct task_group *parent);
extern void sched_online_group(struct task_group *tg,
@@ -558,6 +580,30 @@ struct dl_rq {
#else
struct dl_bw dl_bw;
#endif
+ /*
+ * "Active utilization" for this runqueue: increased when a
+ * task wakes up (becomes TASK_RUNNING) and decreased when a
+ * task blocks
+ */
+ u64 running_bw;
+
+ /*
+ * Utilization of the tasks "assigned" to this runqueue (including
+ * the tasks that are in runqueue and the tasks that executed on this
+ * CPU and blocked). Increased when a task moves to this runqueue, and
+ * decreased when the task moves away (migrates, changes scheduling
+ * policy, or terminates).
+ * This is needed to compute the "inactive utilization" for the
+ * runqueue (inactive utilization = this_bw - running_bw).
+ */
+ u64 this_bw;
+ u64 extra_bw;
+
+ /*
+ * Inverse of the fraction of CPU utilization that can be reclaimed
+ * by the GRUB algorithm.
+ */
+ u64 bw_ratio;
};
#ifdef CONFIG_SMP
@@ -606,11 +652,9 @@ struct root_domain {
extern struct root_domain def_root_domain;
extern struct mutex sched_domains_mutex;
-extern cpumask_var_t fallback_doms;
-extern cpumask_var_t sched_domains_tmpmask;
extern void init_defrootdomain(void);
-extern int init_sched_domains(const struct cpumask *cpu_map);
+extern int sched_init_domains(const struct cpumask *cpu_map);
extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
#endif /* CONFIG_SMP */
@@ -1025,7 +1069,11 @@ struct sched_group_capacity {
unsigned long next_update;
int imbalance; /* XXX unrelated to capacity but shared group state */
- unsigned long cpumask[0]; /* iteration mask */
+#ifdef CONFIG_SCHED_DEBUG
+ int id;
+#endif
+
+ unsigned long cpumask[0]; /* balance mask */
};
struct sched_group {
@@ -1046,16 +1094,15 @@ struct sched_group {
unsigned long cpumask[0];
};
-static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
+static inline struct cpumask *sched_group_span(struct sched_group *sg)
{
return to_cpumask(sg->cpumask);
}
/*
- * cpumask masking which cpus in the group are allowed to iterate up the domain
- * tree.
+ * See build_balance_mask().
*/
-static inline struct cpumask *sched_group_mask(struct sched_group *sg)
+static inline struct cpumask *group_balance_mask(struct sched_group *sg)
{
return to_cpumask(sg->sgc->cpumask);
}
@@ -1066,7 +1113,7 @@ static inline struct cpumask *sched_group_mask(struct sched_group *sg)
*/
static inline unsigned int group_first_cpu(struct sched_group *group)
{
- return cpumask_first(sched_group_cpus(group));
+ return cpumask_first(sched_group_span(group));
}
extern int group_balance_cpu(struct sched_group *sg);
@@ -1422,7 +1469,11 @@ static inline void set_curr_task(struct rq *rq, struct task_struct *curr)
curr->sched_class->set_curr_task(rq);
}
+#ifdef CONFIG_SMP
#define sched_class_highest (&stop_sched_class)
+#else
+#define sched_class_highest (&dl_sched_class)
+#endif
#define for_each_class(class) \
for (class = sched_class_highest; class; class = class->next)
@@ -1486,7 +1537,12 @@ extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime
extern struct dl_bandwidth def_dl_bandwidth;
extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
+extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
+extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
+#define BW_SHIFT 20
+#define BW_UNIT (1 << BW_SHIFT)
+#define RATIO_SHIFT 8
unsigned long to_ratio(u64 period, u64 runtime);
extern void init_entity_runnable_average(struct sched_entity *se);
@@ -1928,6 +1984,33 @@ extern void nohz_balance_exit_idle(unsigned int cpu);
static inline void nohz_balance_exit_idle(unsigned int cpu) { }
#endif
+
+#ifdef CONFIG_SMP
+static inline
+void __dl_update(struct dl_bw *dl_b, s64 bw)
+{
+ struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw);
+ int i;
+
+ RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+ "sched RCU must be held");
+ for_each_cpu_and(i, rd->span, cpu_active_mask) {
+ struct rq *rq = cpu_rq(i);
+
+ rq->dl.extra_bw += bw;
+ }
+}
+#else
+static inline
+void __dl_update(struct dl_bw *dl_b, s64 bw)
+{
+ struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw);
+
+ dl->extra_bw += bw;
+}
+#endif
+
+
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
struct irqtime {
u64 total;
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 1b0b4fb12837..79895aec281e 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -10,6 +10,7 @@ DEFINE_MUTEX(sched_domains_mutex);
/* Protected by sched_domains_mutex: */
cpumask_var_t sched_domains_tmpmask;
+cpumask_var_t sched_domains_tmpmask2;
#ifdef CONFIG_SCHED_DEBUG
@@ -35,7 +36,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpumask_clear(groupmask);
- printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
+ printk(KERN_DEBUG "%*s domain-%d: ", level, "", level);
if (!(sd->flags & SD_LOAD_BALANCE)) {
printk("does not load-balance\n");
@@ -45,14 +46,14 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
return -1;
}
- printk(KERN_CONT "span %*pbl level %s\n",
+ printk(KERN_CONT "span=%*pbl level=%s\n",
cpumask_pr_args(sched_domain_span(sd)), sd->name);
if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
printk(KERN_ERR "ERROR: domain->span does not contain "
"CPU%d\n", cpu);
}
- if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
+ if (!cpumask_test_cpu(cpu, sched_group_span(group))) {
printk(KERN_ERR "ERROR: domain->groups does not contain"
" CPU%d\n", cpu);
}
@@ -65,29 +66,47 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
break;
}
- if (!cpumask_weight(sched_group_cpus(group))) {
+ if (!cpumask_weight(sched_group_span(group))) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: empty group\n");
break;
}
if (!(sd->flags & SD_OVERLAP) &&
- cpumask_intersects(groupmask, sched_group_cpus(group))) {
+ cpumask_intersects(groupmask, sched_group_span(group))) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: repeated CPUs\n");
break;
}
- cpumask_or(groupmask, groupmask, sched_group_cpus(group));
+ cpumask_or(groupmask, groupmask, sched_group_span(group));
- printk(KERN_CONT " %*pbl",
- cpumask_pr_args(sched_group_cpus(group)));
- if (group->sgc->capacity != SCHED_CAPACITY_SCALE) {
- printk(KERN_CONT " (cpu_capacity = %lu)",
- group->sgc->capacity);
+ printk(KERN_CONT " %d:{ span=%*pbl",
+ group->sgc->id,
+ cpumask_pr_args(sched_group_span(group)));
+
+ if ((sd->flags & SD_OVERLAP) &&
+ !cpumask_equal(group_balance_mask(group), sched_group_span(group))) {
+ printk(KERN_CONT " mask=%*pbl",
+ cpumask_pr_args(group_balance_mask(group)));
+ }
+
+ if (group->sgc->capacity != SCHED_CAPACITY_SCALE)
+ printk(KERN_CONT " cap=%lu", group->sgc->capacity);
+
+ if (group == sd->groups && sd->child &&
+ !cpumask_equal(sched_domain_span(sd->child),
+ sched_group_span(group))) {
+ printk(KERN_ERR "ERROR: domain->groups does not match domain->child\n");
}
+ printk(KERN_CONT " }");
+
group = group->next;
+
+ if (group != sd->groups)
+ printk(KERN_CONT ",");
+
} while (group != sd->groups);
printk(KERN_CONT "\n");
@@ -113,7 +132,7 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
return;
}
- printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+ printk(KERN_DEBUG "CPU%d attaching sched-domain(s):\n", cpu);
for (;;) {
if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask))
@@ -477,46 +496,214 @@ enum s_alloc {
};
/*
- * Build an iteration mask that can exclude certain CPUs from the upwards
- * domain traversal.
+ * Return the canonical balance CPU for this group, this is the first CPU
+ * of this group that's also in the balance mask.
*
- * Asymmetric node setups can result in situations where the domain tree is of
- * unequal depth, make sure to skip domains that already cover the entire
- * range.
+ * The balance mask are all those CPUs that could actually end up at this
+ * group. See build_balance_mask().
*
- * In that case build_sched_domains() will have terminated the iteration early
- * and our sibling sd spans will be empty. Domains should always include the
- * CPU they're built on, so check that.
+ * Also see should_we_balance().
*/
-static void build_group_mask(struct sched_domain *sd, struct sched_group *sg)
+int group_balance_cpu(struct sched_group *sg)
{
- const struct cpumask *span = sched_domain_span(sd);
+ return cpumask_first(group_balance_mask(sg));
+}
+
+
+/*
+ * NUMA topology (first read the regular topology blurb below)
+ *
+ * Given a node-distance table, for example:
+ *
+ * node 0 1 2 3
+ * 0: 10 20 30 20
+ * 1: 20 10 20 30
+ * 2: 30 20 10 20
+ * 3: 20 30 20 10
+ *
+ * which represents a 4 node ring topology like:
+ *
+ * 0 ----- 1
+ * | |
+ * | |
+ * | |
+ * 3 ----- 2
+ *
+ * We want to construct domains and groups to represent this. The way we go
+ * about doing this is to build the domains on 'hops'. For each NUMA level we
+ * construct the mask of all nodes reachable in @level hops.
+ *
+ * For the above NUMA topology that gives 3 levels:
+ *
+ * NUMA-2 0-3 0-3 0-3 0-3
+ * groups: {0-1,3},{1-3} {0-2},{0,2-3} {1-3},{0-1,3} {0,2-3},{0-2}
+ *
+ * NUMA-1 0-1,3 0-2 1-3 0,2-3
+ * groups: {0},{1},{3} {0},{1},{2} {1},{2},{3} {0},{2},{3}
+ *
+ * NUMA-0 0 1 2 3
+ *
+ *
+ * As can be seen; things don't nicely line up as with the regular topology.
+ * When we iterate a domain in child domain chunks some nodes can be
+ * represented multiple times -- hence the "overlap" naming for this part of
+ * the topology.
+ *
+ * In order to minimize this overlap, we only build enough groups to cover the
+ * domain. For instance Node-0 NUMA-2 would only get groups: 0-1,3 and 1-3.
+ *
+ * Because:
+ *
+ * - the first group of each domain is its child domain; this
+ * gets us the first 0-1,3
+ * - the only uncovered node is 2, who's child domain is 1-3.
+ *
+ * However, because of the overlap, computing a unique CPU for each group is
+ * more complicated. Consider for instance the groups of NODE-1 NUMA-2, both
+ * groups include the CPUs of Node-0, while those CPUs would not in fact ever
+ * end up at those groups (they would end up in group: 0-1,3).
+ *
+ * To correct this we have to introduce the group balance mask. This mask
+ * will contain those CPUs in the group that can reach this group given the
+ * (child) domain tree.
+ *
+ * With this we can once again compute balance_cpu and sched_group_capacity
+ * relations.
+ *
+ * XXX include words on how balance_cpu is unique and therefore can be
+ * used for sched_group_capacity links.
+ *
+ *
+ * Another 'interesting' topology is:
+ *
+ * node 0 1 2 3
+ * 0: 10 20 20 30
+ * 1: 20 10 20 20
+ * 2: 20 20 10 20
+ * 3: 30 20 20 10
+ *
+ * Which looks a little like:
+ *
+ * 0 ----- 1
+ * | / |
+ * | / |
+ * | / |
+ * 2 ----- 3
+ *
+ * This topology is asymmetric, nodes 1,2 are fully connected, but nodes 0,3
+ * are not.
+ *
+ * This leads to a few particularly weird cases where the sched_domain's are
+ * not of the same number for each cpu. Consider:
+ *
+ * NUMA-2 0-3 0-3
+ * groups: {0-2},{1-3} {1-3},{0-2}
+ *
+ * NUMA-1 0-2 0-3 0-3 1-3
+ *
+ * NUMA-0 0 1 2 3
+ *
+ */
+
+
+/*
+ * Build the balance mask; it contains only those CPUs that can arrive at this
+ * group and should be considered to continue balancing.
+ *
+ * We do this during the group creation pass, therefore the group information
+ * isn't complete yet, however since each group represents a (child) domain we
+ * can fully construct this using the sched_domain bits (which are already
+ * complete).
+ */
+static void
+build_balance_mask(struct sched_domain *sd, struct sched_group *sg, struct cpumask *mask)
+{
+ const struct cpumask *sg_span = sched_group_span(sg);
struct sd_data *sdd = sd->private;
struct sched_domain *sibling;
int i;
- for_each_cpu(i, span) {
+ cpumask_clear(mask);
+
+ for_each_cpu(i, sg_span) {
sibling = *per_cpu_ptr(sdd->sd, i);
- if (!cpumask_test_cpu(i, sched_domain_span(sibling)))
+
+ /*
+ * Can happen in the asymmetric case, where these siblings are
+ * unused. The mask will not be empty because those CPUs that
+ * do have the top domain _should_ span the domain.
+ */
+ if (!sibling->child)
continue;
- cpumask_set_cpu(i, sched_group_mask(sg));
+ /* If we would not end up here, we can't continue from here */
+ if (!cpumask_equal(sg_span, sched_domain_span(sibling->child)))
+ continue;
+
+ cpumask_set_cpu(i, mask);
}
+
+ /* We must not have empty masks here */
+ WARN_ON_ONCE(cpumask_empty(mask));
}
/*
- * Return the canonical balance CPU for this group, this is the first CPU
- * of this group that's also in the iteration mask.
+ * XXX: This creates per-node group entries; since the load-balancer will
+ * immediately access remote memory to construct this group's load-balance
+ * statistics having the groups node local is of dubious benefit.
*/
-int group_balance_cpu(struct sched_group *sg)
+static struct sched_group *
+build_group_from_child_sched_domain(struct sched_domain *sd, int cpu)
{
- return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg));
+ struct sched_group *sg;
+ struct cpumask *sg_span;
+
+ sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, cpu_to_node(cpu));
+
+ if (!sg)
+ return NULL;
+
+ sg_span = sched_group_span(sg);
+ if (sd->child)
+ cpumask_copy(sg_span, sched_domain_span(sd->child));
+ else
+ cpumask_copy(sg_span, sched_domain_span(sd));
+
+ return sg;
+}
+
+static void init_overlap_sched_group(struct sched_domain *sd,
+ struct sched_group *sg)
+{
+ struct cpumask *mask = sched_domains_tmpmask2;
+ struct sd_data *sdd = sd->private;
+ struct cpumask *sg_span;
+ int cpu;
+
+ build_balance_mask(sd, sg, mask);
+ cpu = cpumask_first_and(sched_group_span(sg), mask);
+
+ sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
+ if (atomic_inc_return(&sg->sgc->ref) == 1)
+ cpumask_copy(group_balance_mask(sg), mask);
+ else
+ WARN_ON_ONCE(!cpumask_equal(group_balance_mask(sg), mask));
+
+ /*
+ * Initialize sgc->capacity such that even if we mess up the
+ * domains and no possible iteration will get us here, we won't
+ * die on a /0 trap.
+ */
+ sg_span = sched_group_span(sg);
+ sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span);
+ sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
}
static int
build_overlap_sched_groups(struct sched_domain *sd, int cpu)
{
- struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
+ struct sched_group *first = NULL, *last = NULL, *sg;
const struct cpumask *span = sched_domain_span(sd);
struct cpumask *covered = sched_domains_tmpmask;
struct sd_data *sdd = sd->private;
@@ -525,7 +712,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
cpumask_clear(covered);
- for_each_cpu(i, span) {
+ for_each_cpu_wrap(i, span, cpu) {
struct cpumask *sg_span;
if (cpumask_test_cpu(i, covered))
@@ -533,44 +720,27 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
sibling = *per_cpu_ptr(sdd->sd, i);
- /* See the comment near build_group_mask(). */
+ /*
+ * Asymmetric node setups can result in situations where the
+ * domain tree is of unequal depth, make sure to skip domains
+ * that already cover the entire range.
+ *
+ * In that case build_sched_domains() will have terminated the
+ * iteration early and our sibling sd spans will be empty.
+ * Domains should always include the CPU they're built on, so
+ * check that.
+ */
if (!cpumask_test_cpu(i, sched_domain_span(sibling)))
continue;
- sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
- GFP_KERNEL, cpu_to_node(cpu));
-
+ sg = build_group_from_child_sched_domain(sibling, cpu);
if (!sg)
goto fail;
- sg_span = sched_group_cpus(sg);
- if (sibling->child)
- cpumask_copy(sg_span, sched_domain_span(sibling->child));
- else
- cpumask_set_cpu(i, sg_span);
-
+ sg_span = sched_group_span(sg);
cpumask_or(covered, covered, sg_span);
- sg->sgc = *per_cpu_ptr(sdd->sgc, i);
- if (atomic_inc_return(&sg->sgc->ref) == 1)
- build_group_mask(sd, sg);
-
- /*
- * Initialize sgc->capacity such that even if we mess up the
- * domains and no possible iteration will get us here, we won't
- * die on a /0 trap.
- */
- sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span);
- sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
-
- /*
- * Make sure the first group of this domain contains the
- * canonical balance CPU. Otherwise the sched_domain iteration
- * breaks. See update_sg_lb_stats().
- */
- if ((!groups && cpumask_test_cpu(cpu, sg_span)) ||
- group_balance_cpu(sg) == cpu)
- groups = sg;
+ init_overlap_sched_group(sd, sg);
if (!first)
first = sg;
@@ -579,7 +749,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
last = sg;
last->next = first;
}
- sd->groups = groups;
+ sd->groups = first;
return 0;
@@ -589,23 +759,106 @@ fail:
return -ENOMEM;
}
-static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
+
+/*
+ * Package topology (also see the load-balance blurb in fair.c)
+ *
+ * The scheduler builds a tree structure to represent a number of important
+ * topology features. By default (default_topology[]) these include:
+ *
+ * - Simultaneous multithreading (SMT)
+ * - Multi-Core Cache (MC)
+ * - Package (DIE)
+ *
+ * Where the last one more or less denotes everything up to a NUMA node.
+ *
+ * The tree consists of 3 primary data structures:
+ *
+ * sched_domain -> sched_group -> sched_group_capacity
+ * ^ ^ ^ ^
+ * `-' `-'
+ *
+ * The sched_domains are per-cpu and have a two way link (parent & child) and
+ * denote the ever growing mask of CPUs belonging to that level of topology.
+ *
+ * Each sched_domain has a circular (double) linked list of sched_group's, each
+ * denoting the domains of the level below (or individual CPUs in case of the
+ * first domain level). The sched_group linked by a sched_domain includes the
+ * CPU of that sched_domain [*].
+ *
+ * Take for instance a 2 threaded, 2 core, 2 cache cluster part:
+ *
+ * CPU 0 1 2 3 4 5 6 7
+ *
+ * DIE [ ]
+ * MC [ ] [ ]
+ * SMT [ ] [ ] [ ] [ ]
+ *
+ * - or -
+ *
+ * DIE 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7
+ * MC 0-3 0-3 0-3 0-3 4-7 4-7 4-7 4-7
+ * SMT 0-1 0-1 2-3 2-3 4-5 4-5 6-7 6-7
+ *
+ * CPU 0 1 2 3 4 5 6 7
+ *
+ * One way to think about it is: sched_domain moves you up and down among these
+ * topology levels, while sched_group moves you sideways through it, at child
+ * domain granularity.
+ *
+ * sched_group_capacity ensures each unique sched_group has shared storage.
+ *
+ * There are two related construction problems, both require a CPU that
+ * uniquely identify each group (for a given domain):
+ *
+ * - The first is the balance_cpu (see should_we_balance() and the
+ * load-balance blub in fair.c); for each group we only want 1 CPU to
+ * continue balancing at a higher domain.
+ *
+ * - The second is the sched_group_capacity; we want all identical groups
+ * to share a single sched_group_capacity.
+ *
+ * Since these topologies are exclusive by construction. That is, its
+ * impossible for an SMT thread to belong to multiple cores, and cores to
+ * be part of multiple caches. There is a very clear and unique location
+ * for each CPU in the hierarchy.
+ *
+ * Therefore computing a unique CPU for each group is trivial (the iteration
+ * mask is redundant and set all 1s; all CPUs in a group will end up at _that_
+ * group), we can simply pick the first CPU in each group.
+ *
+ *
+ * [*] in other words, the first group of each domain is its child domain.
+ */
+
+static struct sched_group *get_group(int cpu, struct sd_data *sdd)
{
struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
struct sched_domain *child = sd->child;
+ struct sched_group *sg;
if (child)
cpu = cpumask_first(sched_domain_span(child));
- if (sg) {
- *sg = *per_cpu_ptr(sdd->sg, cpu);
- (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu);
+ sg = *per_cpu_ptr(sdd->sg, cpu);
+ sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
+
+ /* For claim_allocations: */
+ atomic_inc(&sg->ref);
+ atomic_inc(&sg->sgc->ref);
- /* For claim_allocations: */
- atomic_set(&(*sg)->sgc->ref, 1);
+ if (child) {
+ cpumask_copy(sched_group_span(sg), sched_domain_span(child));
+ cpumask_copy(group_balance_mask(sg), sched_group_span(sg));
+ } else {
+ cpumask_set_cpu(cpu, sched_group_span(sg));
+ cpumask_set_cpu(cpu, group_balance_mask(sg));
}
- return cpu;
+ sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sched_group_span(sg));
+ sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
+
+ return sg;
}
/*
@@ -624,34 +877,20 @@ build_sched_groups(struct sched_domain *sd, int cpu)
struct cpumask *covered;
int i;
- get_group(cpu, sdd, &sd->groups);
- atomic_inc(&sd->groups->ref);
-
- if (cpu != cpumask_first(span))
- return 0;
-
lockdep_assert_held(&sched_domains_mutex);
covered = sched_domains_tmpmask;
cpumask_clear(covered);
- for_each_cpu(i, span) {
+ for_each_cpu_wrap(i, span, cpu) {
struct sched_group *sg;
- int group, j;
if (cpumask_test_cpu(i, covered))
continue;
- group = get_group(i, sdd, &sg);
- cpumask_setall(sched_group_mask(sg));
+ sg = get_group(i, sdd);
- for_each_cpu(j, span) {
- if (get_group(j, sdd, NULL) != group)
- continue;
-
- cpumask_set_cpu(j, covered);
- cpumask_set_cpu(j, sched_group_cpus(sg));
- }
+ cpumask_or(covered, covered, sched_group_span(sg));
if (!first)
first = sg;
@@ -660,6 +899,7 @@ build_sched_groups(struct sched_domain *sd, int cpu)
last = sg;
}
last->next = first;
+ sd->groups = first;
return 0;
}
@@ -683,12 +923,12 @@ static void init_sched_groups_capacity(int cpu, struct sched_domain *sd)
do {
int cpu, max_cpu = -1;
- sg->group_weight = cpumask_weight(sched_group_cpus(sg));
+ sg->group_weight = cpumask_weight(sched_group_span(sg));
if (!(sd->flags & SD_ASYM_PACKING))
goto next;
- for_each_cpu(cpu, sched_group_cpus(sg)) {
+ for_each_cpu(cpu, sched_group_span(sg)) {
if (max_cpu < 0)
max_cpu = cpu;
else if (sched_asym_prefer(cpu, max_cpu))
@@ -1308,6 +1548,10 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
if (!sgc)
return -ENOMEM;
+#ifdef CONFIG_SCHED_DEBUG
+ sgc->id = j;
+#endif
+
*per_cpu_ptr(sdd->sgc, j) = sgc;
}
}
@@ -1407,7 +1651,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
sd = build_sched_domain(tl, cpu_map, attr, sd, i);
if (tl == sched_domain_topology)
*per_cpu_ptr(d.sd, i) = sd;
- if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
+ if (tl->flags & SDTL_OVERLAP)
sd->flags |= SD_OVERLAP;
if (cpumask_equal(cpu_map, sched_domain_span(sd)))
break;
@@ -1478,7 +1722,7 @@ static struct sched_domain_attr *dattr_cur;
* cpumask) fails, then fallback to a single sched domain,
* as determined by the single cpumask fallback_doms.
*/
-cpumask_var_t fallback_doms;
+static cpumask_var_t fallback_doms;
/*
* arch_update_cpu_topology lets virtualized architectures update the
@@ -1520,10 +1764,14 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
* For now this just excludes isolated CPUs, but could be used to
* exclude other special cases in the future.
*/
-int init_sched_domains(const struct cpumask *cpu_map)
+int sched_init_domains(const struct cpumask *cpu_map)
{
int err;
+ zalloc_cpumask_var(&sched_domains_tmpmask, GFP_KERNEL);
+ zalloc_cpumask_var(&sched_domains_tmpmask2, GFP_KERNEL);
+ zalloc_cpumask_var(&fallback_doms, GFP_KERNEL);
+
arch_update_cpu_topology();
ndoms_cur = 1;
doms_cur = alloc_sched_domains(ndoms_cur);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index b8c84c6dee64..17f11c6b0a9f 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -12,44 +12,44 @@
#include <linux/hash.h>
#include <linux/kthread.h>
-void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *key)
+void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *key)
{
- spin_lock_init(&q->lock);
- lockdep_set_class_and_name(&q->lock, key, name);
- INIT_LIST_HEAD(&q->task_list);
+ spin_lock_init(&wq_head->lock);
+ lockdep_set_class_and_name(&wq_head->lock, key, name);
+ INIT_LIST_HEAD(&wq_head->head);
}
EXPORT_SYMBOL(__init_waitqueue_head);
-void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
+void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
{
unsigned long flags;
- wait->flags &= ~WQ_FLAG_EXCLUSIVE;
- spin_lock_irqsave(&q->lock, flags);
- __add_wait_queue(q, wait);
- spin_unlock_irqrestore(&q->lock, flags);
+ wq_entry->flags &= ~WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __add_wait_queue_entry_tail(wq_head, wq_entry);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(add_wait_queue);
-void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
+void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
{
unsigned long flags;
- wait->flags |= WQ_FLAG_EXCLUSIVE;
- spin_lock_irqsave(&q->lock, flags);
- __add_wait_queue_tail(q, wait);
- spin_unlock_irqrestore(&q->lock, flags);
+ wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __add_wait_queue_entry_tail(wq_head, wq_entry);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(add_wait_queue_exclusive);
-void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
+void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
{
unsigned long flags;
- spin_lock_irqsave(&q->lock, flags);
- __remove_wait_queue(q, wait);
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __remove_wait_queue(wq_head, wq_entry);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(remove_wait_queue);
@@ -63,12 +63,12 @@ EXPORT_SYMBOL(remove_wait_queue);
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
-static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
+static void __wake_up_common(struct wait_queue_head *wq_head, unsigned int mode,
int nr_exclusive, int wake_flags, void *key)
{
- wait_queue_t *curr, *next;
+ wait_queue_entry_t *curr, *next;
- list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
+ list_for_each_entry_safe(curr, next, &wq_head->head, entry) {
unsigned flags = curr->flags;
if (curr->func(curr, mode, wake_flags, key) &&
@@ -79,7 +79,7 @@ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
/**
* __wake_up - wake up threads blocked on a waitqueue.
- * @q: the waitqueue
+ * @wq_head: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: is directly passed to the wakeup function
@@ -87,35 +87,35 @@ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
-void __wake_up(wait_queue_head_t *q, unsigned int mode,
+void __wake_up(struct wait_queue_head *wq_head, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
- spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, 0, key);
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __wake_up_common(wq_head, mode, nr_exclusive, 0, key);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(__wake_up);
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
-void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
+void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr)
{
- __wake_up_common(q, mode, nr, 0, NULL);
+ __wake_up_common(wq_head, mode, nr, 0, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
-void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
+void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key)
{
- __wake_up_common(q, mode, 1, 0, key);
+ __wake_up_common(wq_head, mode, 1, 0, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
/**
* __wake_up_sync_key - wake up threads blocked on a waitqueue.
- * @q: the waitqueue
+ * @wq_head: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: opaque value to be passed to wakeup targets
@@ -130,30 +130,30 @@ EXPORT_SYMBOL_GPL(__wake_up_locked_key);
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
-void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
+void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
int wake_flags = 1; /* XXX WF_SYNC */
- if (unlikely(!q))
+ if (unlikely(!wq_head))
return;
if (unlikely(nr_exclusive != 1))
wake_flags = 0;
- spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __wake_up_common(wq_head, mode, nr_exclusive, wake_flags, key);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
/*
* __wake_up_sync - see __wake_up_sync_key()
*/
-void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
+void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr_exclusive)
{
- __wake_up_sync_key(q, mode, nr_exclusive, NULL);
+ __wake_up_sync_key(wq_head, mode, nr_exclusive, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
@@ -170,48 +170,48 @@ EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
* loads to move into the critical region).
*/
void
-prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
+prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state)
{
unsigned long flags;
- wait->flags &= ~WQ_FLAG_EXCLUSIVE;
- spin_lock_irqsave(&q->lock, flags);
- if (list_empty(&wait->task_list))
- __add_wait_queue(q, wait);
+ wq_entry->flags &= ~WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ if (list_empty(&wq_entry->entry))
+ __add_wait_queue(wq_head, wq_entry);
set_current_state(state);
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(prepare_to_wait);
void
-prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
+prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state)
{
unsigned long flags;
- wait->flags |= WQ_FLAG_EXCLUSIVE;
- spin_lock_irqsave(&q->lock, flags);
- if (list_empty(&wait->task_list))
- __add_wait_queue_tail(q, wait);
+ wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ if (list_empty(&wq_entry->entry))
+ __add_wait_queue_entry_tail(wq_head, wq_entry);
set_current_state(state);
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
EXPORT_SYMBOL(prepare_to_wait_exclusive);
-void init_wait_entry(wait_queue_t *wait, int flags)
+void init_wait_entry(struct wait_queue_entry *wq_entry, int flags)
{
- wait->flags = flags;
- wait->private = current;
- wait->func = autoremove_wake_function;
- INIT_LIST_HEAD(&wait->task_list);
+ wq_entry->flags = flags;
+ wq_entry->private = current;
+ wq_entry->func = autoremove_wake_function;
+ INIT_LIST_HEAD(&wq_entry->entry);
}
EXPORT_SYMBOL(init_wait_entry);
-long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state)
+long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state)
{
unsigned long flags;
long ret = 0;
- spin_lock_irqsave(&q->lock, flags);
+ spin_lock_irqsave(&wq_head->lock, flags);
if (unlikely(signal_pending_state(state, current))) {
/*
* Exclusive waiter must not fail if it was selected by wakeup,
@@ -219,24 +219,24 @@ long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state)
*
* The caller will recheck the condition and return success if
* we were already woken up, we can not miss the event because
- * wakeup locks/unlocks the same q->lock.
+ * wakeup locks/unlocks the same wq_head->lock.
*
* But we need to ensure that set-condition + wakeup after that
* can't see us, it should wake up another exclusive waiter if
* we fail.
*/
- list_del_init(&wait->task_list);
+ list_del_init(&wq_entry->entry);
ret = -ERESTARTSYS;
} else {
- if (list_empty(&wait->task_list)) {
- if (wait->flags & WQ_FLAG_EXCLUSIVE)
- __add_wait_queue_tail(q, wait);
+ if (list_empty(&wq_entry->entry)) {
+ if (wq_entry->flags & WQ_FLAG_EXCLUSIVE)
+ __add_wait_queue_entry_tail(wq_head, wq_entry);
else
- __add_wait_queue(q, wait);
+ __add_wait_queue(wq_head, wq_entry);
}
set_current_state(state);
}
- spin_unlock_irqrestore(&q->lock, flags);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
return ret;
}
@@ -249,10 +249,10 @@ EXPORT_SYMBOL(prepare_to_wait_event);
* condition in the caller before they add the wait
* entry to the wake queue.
*/
-int do_wait_intr(wait_queue_head_t *wq, wait_queue_t *wait)
+int do_wait_intr(wait_queue_head_t *wq, wait_queue_entry_t *wait)
{
- if (likely(list_empty(&wait->task_list)))
- __add_wait_queue_tail(wq, wait);
+ if (likely(list_empty(&wait->entry)))
+ __add_wait_queue_entry_tail(wq, wait);
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current))
@@ -265,10 +265,10 @@ int do_wait_intr(wait_queue_head_t *wq, wait_queue_t *wait)
}
EXPORT_SYMBOL(do_wait_intr);
-int do_wait_intr_irq(wait_queue_head_t *wq, wait_queue_t *wait)
+int do_wait_intr_irq(wait_queue_head_t *wq, wait_queue_entry_t *wait)
{
- if (likely(list_empty(&wait->task_list)))
- __add_wait_queue_tail(wq, wait);
+ if (likely(list_empty(&wait->entry)))
+ __add_wait_queue_entry_tail(wq, wait);
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current))
@@ -283,14 +283,14 @@ EXPORT_SYMBOL(do_wait_intr_irq);
/**
* finish_wait - clean up after waiting in a queue
- * @q: waitqueue waited on
- * @wait: wait descriptor
+ * @wq_head: waitqueue waited on
+ * @wq_entry: wait descriptor
*
* Sets current thread back to running state and removes
* the wait descriptor from the given waitqueue if still
* queued.
*/
-void finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
+void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
{
unsigned long flags;
@@ -308,20 +308,20 @@ void finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
* have _one_ other CPU that looks at or modifies
* the list).
*/
- if (!list_empty_careful(&wait->task_list)) {
- spin_lock_irqsave(&q->lock, flags);
- list_del_init(&wait->task_list);
- spin_unlock_irqrestore(&q->lock, flags);
+ if (!list_empty_careful(&wq_entry->entry)) {
+ spin_lock_irqsave(&wq_head->lock, flags);
+ list_del_init(&wq_entry->entry);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
}
}
EXPORT_SYMBOL(finish_wait);
-int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
+int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key)
{
- int ret = default_wake_function(wait, mode, sync, key);
+ int ret = default_wake_function(wq_entry, mode, sync, key);
if (ret)
- list_del_init(&wait->task_list);
+ list_del_init(&wq_entry->entry);
return ret;
}
EXPORT_SYMBOL(autoremove_wake_function);
@@ -334,24 +334,24 @@ static inline bool is_kthread_should_stop(void)
/*
* DEFINE_WAIT_FUNC(wait, woken_wake_func);
*
- * add_wait_queue(&wq, &wait);
+ * add_wait_queue(&wq_head, &wait);
* for (;;) {
* if (condition)
* break;
*
* p->state = mode; condition = true;
* smp_mb(); // A smp_wmb(); // C
- * if (!wait->flags & WQ_FLAG_WOKEN) wait->flags |= WQ_FLAG_WOKEN;
+ * if (!wq_entry->flags & WQ_FLAG_WOKEN) wq_entry->flags |= WQ_FLAG_WOKEN;
* schedule() try_to_wake_up();
* p->state = TASK_RUNNING; ~~~~~~~~~~~~~~~~~~
- * wait->flags &= ~WQ_FLAG_WOKEN; condition = true;
+ * wq_entry->flags &= ~WQ_FLAG_WOKEN; condition = true;
* smp_mb() // B smp_wmb(); // C
- * wait->flags |= WQ_FLAG_WOKEN;
+ * wq_entry->flags |= WQ_FLAG_WOKEN;
* }
- * remove_wait_queue(&wq, &wait);
+ * remove_wait_queue(&wq_head, &wait);
*
*/
-long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
+long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout)
{
set_current_state(mode); /* A */
/*
@@ -359,7 +359,7 @@ long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
* woken_wake_function() such that if we observe WQ_FLAG_WOKEN we must
* also observe all state before the wakeup.
*/
- if (!(wait->flags & WQ_FLAG_WOKEN) && !is_kthread_should_stop())
+ if (!(wq_entry->flags & WQ_FLAG_WOKEN) && !is_kthread_should_stop())
timeout = schedule_timeout(timeout);
__set_current_state(TASK_RUNNING);
@@ -369,13 +369,13 @@ long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
* condition being true _OR_ WQ_FLAG_WOKEN such that we will not miss
* an event.
*/
- smp_store_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
+ smp_store_mb(wq_entry->flags, wq_entry->flags & ~WQ_FLAG_WOKEN); /* B */
return timeout;
}
EXPORT_SYMBOL(wait_woken);
-int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
+int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key)
{
/*
* Although this function is called under waitqueue lock, LOCK
@@ -385,267 +385,8 @@ int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
* and is paired with smp_store_mb() in wait_woken().
*/
smp_wmb(); /* C */
- wait->flags |= WQ_FLAG_WOKEN;
+ wq_entry->flags |= WQ_FLAG_WOKEN;
- return default_wake_function(wait, mode, sync, key);
+ return default_wake_function(wq_entry, mode, sync, key);
}
EXPORT_SYMBOL(woken_wake_function);
-
-int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg)
-{
- struct wait_bit_key *key = arg;
- struct wait_bit_queue *wait_bit
- = container_of(wait, struct wait_bit_queue, wait);
-
- if (wait_bit->key.flags != key->flags ||
- wait_bit->key.bit_nr != key->bit_nr ||
- test_bit(key->bit_nr, key->flags))
- return 0;
- else
- return autoremove_wake_function(wait, mode, sync, key);
-}
-EXPORT_SYMBOL(wake_bit_function);
-
-/*
- * To allow interruptible waiting and asynchronous (i.e. nonblocking)
- * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are
- * permitted return codes. Nonzero return codes halt waiting and return.
- */
-int __sched
-__wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q,
- wait_bit_action_f *action, unsigned mode)
-{
- int ret = 0;
-
- do {
- prepare_to_wait(wq, &q->wait, mode);
- if (test_bit(q->key.bit_nr, q->key.flags))
- ret = (*action)(&q->key, mode);
- } while (test_bit(q->key.bit_nr, q->key.flags) && !ret);
- finish_wait(wq, &q->wait);
- return ret;
-}
-EXPORT_SYMBOL(__wait_on_bit);
-
-int __sched out_of_line_wait_on_bit(void *word, int bit,
- wait_bit_action_f *action, unsigned mode)
-{
- wait_queue_head_t *wq = bit_waitqueue(word, bit);
- DEFINE_WAIT_BIT(wait, word, bit);
-
- return __wait_on_bit(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_bit);
-
-int __sched out_of_line_wait_on_bit_timeout(
- void *word, int bit, wait_bit_action_f *action,
- unsigned mode, unsigned long timeout)
-{
- wait_queue_head_t *wq = bit_waitqueue(word, bit);
- DEFINE_WAIT_BIT(wait, word, bit);
-
- wait.key.timeout = jiffies + timeout;
- return __wait_on_bit(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout);
-
-int __sched
-__wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q,
- wait_bit_action_f *action, unsigned mode)
-{
- int ret = 0;
-
- for (;;) {
- prepare_to_wait_exclusive(wq, &q->wait, mode);
- if (test_bit(q->key.bit_nr, q->key.flags)) {
- ret = action(&q->key, mode);
- /*
- * See the comment in prepare_to_wait_event().
- * finish_wait() does not necessarily takes wq->lock,
- * but test_and_set_bit() implies mb() which pairs with
- * smp_mb__after_atomic() before wake_up_page().
- */
- if (ret)
- finish_wait(wq, &q->wait);
- }
- if (!test_and_set_bit(q->key.bit_nr, q->key.flags)) {
- if (!ret)
- finish_wait(wq, &q->wait);
- return 0;
- } else if (ret) {
- return ret;
- }
- }
-}
-EXPORT_SYMBOL(__wait_on_bit_lock);
-
-int __sched out_of_line_wait_on_bit_lock(void *word, int bit,
- wait_bit_action_f *action, unsigned mode)
-{
- wait_queue_head_t *wq = bit_waitqueue(word, bit);
- DEFINE_WAIT_BIT(wait, word, bit);
-
- return __wait_on_bit_lock(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
-
-void __wake_up_bit(wait_queue_head_t *wq, void *word, int bit)
-{
- struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
- if (waitqueue_active(wq))
- __wake_up(wq, TASK_NORMAL, 1, &key);
-}
-EXPORT_SYMBOL(__wake_up_bit);
-
-/**
- * wake_up_bit - wake up a waiter on a bit
- * @word: the word being waited on, a kernel virtual address
- * @bit: the bit of the word being waited on
- *
- * There is a standard hashed waitqueue table for generic use. This
- * is the part of the hashtable's accessor API that wakes up waiters
- * on a bit. For instance, if one were to have waiters on a bitflag,
- * one would call wake_up_bit() after clearing the bit.
- *
- * In order for this to function properly, as it uses waitqueue_active()
- * internally, some kind of memory barrier must be done prior to calling
- * this. Typically, this will be smp_mb__after_atomic(), but in some
- * cases where bitflags are manipulated non-atomically under a lock, one
- * may need to use a less regular barrier, such fs/inode.c's smp_mb(),
- * because spin_unlock() does not guarantee a memory barrier.
- */
-void wake_up_bit(void *word, int bit)
-{
- __wake_up_bit(bit_waitqueue(word, bit), word, bit);
-}
-EXPORT_SYMBOL(wake_up_bit);
-
-/*
- * Manipulate the atomic_t address to produce a better bit waitqueue table hash
- * index (we're keying off bit -1, but that would produce a horrible hash
- * value).
- */
-static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p)
-{
- if (BITS_PER_LONG == 64) {
- unsigned long q = (unsigned long)p;
- return bit_waitqueue((void *)(q & ~1), q & 1);
- }
- return bit_waitqueue(p, 0);
-}
-
-static int wake_atomic_t_function(wait_queue_t *wait, unsigned mode, int sync,
- void *arg)
-{
- struct wait_bit_key *key = arg;
- struct wait_bit_queue *wait_bit
- = container_of(wait, struct wait_bit_queue, wait);
- atomic_t *val = key->flags;
-
- if (wait_bit->key.flags != key->flags ||
- wait_bit->key.bit_nr != key->bit_nr ||
- atomic_read(val) != 0)
- return 0;
- return autoremove_wake_function(wait, mode, sync, key);
-}
-
-/*
- * To allow interruptible waiting and asynchronous (i.e. nonblocking) waiting,
- * the actions of __wait_on_atomic_t() are permitted return codes. Nonzero
- * return codes halt waiting and return.
- */
-static __sched
-int __wait_on_atomic_t(wait_queue_head_t *wq, struct wait_bit_queue *q,
- int (*action)(atomic_t *), unsigned mode)
-{
- atomic_t *val;
- int ret = 0;
-
- do {
- prepare_to_wait(wq, &q->wait, mode);
- val = q->key.flags;
- if (atomic_read(val) == 0)
- break;
- ret = (*action)(val);
- } while (!ret && atomic_read(val) != 0);
- finish_wait(wq, &q->wait);
- return ret;
-}
-
-#define DEFINE_WAIT_ATOMIC_T(name, p) \
- struct wait_bit_queue name = { \
- .key = __WAIT_ATOMIC_T_KEY_INITIALIZER(p), \
- .wait = { \
- .private = current, \
- .func = wake_atomic_t_function, \
- .task_list = \
- LIST_HEAD_INIT((name).wait.task_list), \
- }, \
- }
-
-__sched int out_of_line_wait_on_atomic_t(atomic_t *p, int (*action)(atomic_t *),
- unsigned mode)
-{
- wait_queue_head_t *wq = atomic_t_waitqueue(p);
- DEFINE_WAIT_ATOMIC_T(wait, p);
-
- return __wait_on_atomic_t(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
-
-/**
- * wake_up_atomic_t - Wake up a waiter on a atomic_t
- * @p: The atomic_t being waited on, a kernel virtual address
- *
- * Wake up anyone waiting for the atomic_t to go to zero.
- *
- * Abuse the bit-waker function and its waitqueue hash table set (the atomic_t
- * check is done by the waiter's wake function, not the by the waker itself).
- */
-void wake_up_atomic_t(atomic_t *p)
-{
- __wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR);
-}
-EXPORT_SYMBOL(wake_up_atomic_t);
-
-__sched int bit_wait(struct wait_bit_key *word, int mode)
-{
- schedule();
- if (signal_pending_state(mode, current))
- return -EINTR;
- return 0;
-}
-EXPORT_SYMBOL(bit_wait);
-
-__sched int bit_wait_io(struct wait_bit_key *word, int mode)
-{
- io_schedule();
- if (signal_pending_state(mode, current))
- return -EINTR;
- return 0;
-}
-EXPORT_SYMBOL(bit_wait_io);
-
-__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
-{
- unsigned long now = READ_ONCE(jiffies);
- if (time_after_eq(now, word->timeout))
- return -EAGAIN;
- schedule_timeout(word->timeout - now);
- if (signal_pending_state(mode, current))
- return -EINTR;
- return 0;
-}
-EXPORT_SYMBOL_GPL(bit_wait_timeout);
-
-__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
-{
- unsigned long now = READ_ONCE(jiffies);
- if (time_after_eq(now, word->timeout))
- return -EAGAIN;
- io_schedule_timeout(word->timeout - now);
- if (signal_pending_state(mode, current))
- return -EINTR;
- return 0;
-}
-EXPORT_SYMBOL_GPL(bit_wait_io_timeout);
diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c
new file mode 100644
index 000000000000..f8159698aa4d
--- /dev/null
+++ b/kernel/sched/wait_bit.c
@@ -0,0 +1,286 @@
+/*
+ * The implementation of the wait_bit*() and related waiting APIs:
+ */
+#include <linux/wait_bit.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/debug.h>
+#include <linux/hash.h>
+
+#define WAIT_TABLE_BITS 8
+#define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
+
+static wait_queue_head_t bit_wait_table[WAIT_TABLE_SIZE] __cacheline_aligned;
+
+wait_queue_head_t *bit_waitqueue(void *word, int bit)
+{
+ const int shift = BITS_PER_LONG == 32 ? 5 : 6;
+ unsigned long val = (unsigned long)word << shift | bit;
+
+ return bit_wait_table + hash_long(val, WAIT_TABLE_BITS);
+}
+EXPORT_SYMBOL(bit_waitqueue);
+
+int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *arg)
+{
+ struct wait_bit_key *key = arg;
+ struct wait_bit_queue_entry *wait_bit = container_of(wq_entry, struct wait_bit_queue_entry, wq_entry);
+
+ if (wait_bit->key.flags != key->flags ||
+ wait_bit->key.bit_nr != key->bit_nr ||
+ test_bit(key->bit_nr, key->flags))
+ return 0;
+ else
+ return autoremove_wake_function(wq_entry, mode, sync, key);
+}
+EXPORT_SYMBOL(wake_bit_function);
+
+/*
+ * To allow interruptible waiting and asynchronous (i.e. nonblocking)
+ * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are
+ * permitted return codes. Nonzero return codes halt waiting and return.
+ */
+int __sched
+__wait_on_bit(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry,
+ wait_bit_action_f *action, unsigned mode)
+{
+ int ret = 0;
+
+ do {
+ prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode);
+ if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags))
+ ret = (*action)(&wbq_entry->key, mode);
+ } while (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret);
+ finish_wait(wq_head, &wbq_entry->wq_entry);
+ return ret;
+}
+EXPORT_SYMBOL(__wait_on_bit);
+
+int __sched out_of_line_wait_on_bit(void *word, int bit,
+ wait_bit_action_f *action, unsigned mode)
+{
+ struct wait_queue_head *wq_head = bit_waitqueue(word, bit);
+ DEFINE_WAIT_BIT(wq_entry, word, bit);
+
+ return __wait_on_bit(wq_head, &wq_entry, action, mode);
+}
+EXPORT_SYMBOL(out_of_line_wait_on_bit);
+
+int __sched out_of_line_wait_on_bit_timeout(
+ void *word, int bit, wait_bit_action_f *action,
+ unsigned mode, unsigned long timeout)
+{
+ struct wait_queue_head *wq_head = bit_waitqueue(word, bit);
+ DEFINE_WAIT_BIT(wq_entry, word, bit);
+
+ wq_entry.key.timeout = jiffies + timeout;
+ return __wait_on_bit(wq_head, &wq_entry, action, mode);
+}
+EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout);
+
+int __sched
+__wait_on_bit_lock(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry,
+ wait_bit_action_f *action, unsigned mode)
+{
+ int ret = 0;
+
+ for (;;) {
+ prepare_to_wait_exclusive(wq_head, &wbq_entry->wq_entry, mode);
+ if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags)) {
+ ret = action(&wbq_entry->key, mode);
+ /*
+ * See the comment in prepare_to_wait_event().
+ * finish_wait() does not necessarily takes wwq_head->lock,
+ * but test_and_set_bit() implies mb() which pairs with
+ * smp_mb__after_atomic() before wake_up_page().
+ */
+ if (ret)
+ finish_wait(wq_head, &wbq_entry->wq_entry);
+ }
+ if (!test_and_set_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags)) {
+ if (!ret)
+ finish_wait(wq_head, &wbq_entry->wq_entry);
+ return 0;
+ } else if (ret) {
+ return ret;
+ }
+ }
+}
+EXPORT_SYMBOL(__wait_on_bit_lock);
+
+int __sched out_of_line_wait_on_bit_lock(void *word, int bit,
+ wait_bit_action_f *action, unsigned mode)
+{
+ struct wait_queue_head *wq_head = bit_waitqueue(word, bit);
+ DEFINE_WAIT_BIT(wq_entry, word, bit);
+
+ return __wait_on_bit_lock(wq_head, &wq_entry, action, mode);
+}
+EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
+
+void __wake_up_bit(struct wait_queue_head *wq_head, void *word, int bit)
+{
+ struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
+ if (waitqueue_active(wq_head))
+ __wake_up(wq_head, TASK_NORMAL, 1, &key);
+}
+EXPORT_SYMBOL(__wake_up_bit);
+
+/**
+ * wake_up_bit - wake up a waiter on a bit
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that wakes up waiters
+ * on a bit. For instance, if one were to have waiters on a bitflag,
+ * one would call wake_up_bit() after clearing the bit.
+ *
+ * In order for this to function properly, as it uses waitqueue_active()
+ * internally, some kind of memory barrier must be done prior to calling
+ * this. Typically, this will be smp_mb__after_atomic(), but in some
+ * cases where bitflags are manipulated non-atomically under a lock, one
+ * may need to use a less regular barrier, such fs/inode.c's smp_mb(),
+ * because spin_unlock() does not guarantee a memory barrier.
+ */
+void wake_up_bit(void *word, int bit)
+{
+ __wake_up_bit(bit_waitqueue(word, bit), word, bit);
+}
+EXPORT_SYMBOL(wake_up_bit);
+
+/*
+ * Manipulate the atomic_t address to produce a better bit waitqueue table hash
+ * index (we're keying off bit -1, but that would produce a horrible hash
+ * value).
+ */
+static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p)
+{
+ if (BITS_PER_LONG == 64) {
+ unsigned long q = (unsigned long)p;
+ return bit_waitqueue((void *)(q & ~1), q & 1);
+ }
+ return bit_waitqueue(p, 0);
+}
+
+static int wake_atomic_t_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync,
+ void *arg)
+{
+ struct wait_bit_key *key = arg;
+ struct wait_bit_queue_entry *wait_bit = container_of(wq_entry, struct wait_bit_queue_entry, wq_entry);
+ atomic_t *val = key->flags;
+
+ if (wait_bit->key.flags != key->flags ||
+ wait_bit->key.bit_nr != key->bit_nr ||
+ atomic_read(val) != 0)
+ return 0;
+ return autoremove_wake_function(wq_entry, mode, sync, key);
+}
+
+/*
+ * To allow interruptible waiting and asynchronous (i.e. nonblocking) waiting,
+ * the actions of __wait_on_atomic_t() are permitted return codes. Nonzero
+ * return codes halt waiting and return.
+ */
+static __sched
+int __wait_on_atomic_t(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry,
+ int (*action)(atomic_t *), unsigned mode)
+{
+ atomic_t *val;
+ int ret = 0;
+
+ do {
+ prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode);
+ val = wbq_entry->key.flags;
+ if (atomic_read(val) == 0)
+ break;
+ ret = (*action)(val);
+ } while (!ret && atomic_read(val) != 0);
+ finish_wait(wq_head, &wbq_entry->wq_entry);
+ return ret;
+}
+
+#define DEFINE_WAIT_ATOMIC_T(name, p) \
+ struct wait_bit_queue_entry name = { \
+ .key = __WAIT_ATOMIC_T_KEY_INITIALIZER(p), \
+ .wq_entry = { \
+ .private = current, \
+ .func = wake_atomic_t_function, \
+ .entry = \
+ LIST_HEAD_INIT((name).wq_entry.entry), \
+ }, \
+ }
+
+__sched int out_of_line_wait_on_atomic_t(atomic_t *p, int (*action)(atomic_t *),
+ unsigned mode)
+{
+ struct wait_queue_head *wq_head = atomic_t_waitqueue(p);
+ DEFINE_WAIT_ATOMIC_T(wq_entry, p);
+
+ return __wait_on_atomic_t(wq_head, &wq_entry, action, mode);
+}
+EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
+
+/**
+ * wake_up_atomic_t - Wake up a waiter on a atomic_t
+ * @p: The atomic_t being waited on, a kernel virtual address
+ *
+ * Wake up anyone waiting for the atomic_t to go to zero.
+ *
+ * Abuse the bit-waker function and its waitqueue hash table set (the atomic_t
+ * check is done by the waiter's wake function, not the by the waker itself).
+ */
+void wake_up_atomic_t(atomic_t *p)
+{
+ __wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR);
+}
+EXPORT_SYMBOL(wake_up_atomic_t);
+
+__sched int bit_wait(struct wait_bit_key *word, int mode)
+{
+ schedule();
+ if (signal_pending_state(mode, current))
+ return -EINTR;
+ return 0;
+}
+EXPORT_SYMBOL(bit_wait);
+
+__sched int bit_wait_io(struct wait_bit_key *word, int mode)
+{
+ io_schedule();
+ if (signal_pending_state(mode, current))
+ return -EINTR;
+ return 0;
+}
+EXPORT_SYMBOL(bit_wait_io);
+
+__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
+{
+ unsigned long now = READ_ONCE(jiffies);
+ if (time_after_eq(now, word->timeout))
+ return -EAGAIN;
+ schedule_timeout(word->timeout - now);
+ if (signal_pending_state(mode, current))
+ return -EINTR;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bit_wait_timeout);
+
+__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
+{
+ unsigned long now = READ_ONCE(jiffies);
+ if (time_after_eq(now, word->timeout))
+ return -EAGAIN;
+ io_schedule_timeout(word->timeout - now);
+ if (signal_pending_state(mode, current))
+ return -EINTR;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bit_wait_io_timeout);
+
+void __init wait_bit_init(void)
+{
+ int i;
+
+ for (i = 0; i < WAIT_TABLE_SIZE; i++)
+ init_waitqueue_head(bit_wait_table + i);
+}
diff --git a/kernel/smp.c b/kernel/smp.c
index a817769b53c0..3061483cb3ad 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -30,6 +30,7 @@ enum {
struct call_function_data {
struct call_single_data __percpu *csd;
cpumask_var_t cpumask;
+ cpumask_var_t cpumask_ipi;
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
@@ -45,9 +46,15 @@ int smpcfd_prepare_cpu(unsigned int cpu)
if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
cpu_to_node(cpu)))
return -ENOMEM;
+ if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL,
+ cpu_to_node(cpu))) {
+ free_cpumask_var(cfd->cpumask);
+ return -ENOMEM;
+ }
cfd->csd = alloc_percpu(struct call_single_data);
if (!cfd->csd) {
free_cpumask_var(cfd->cpumask);
+ free_cpumask_var(cfd->cpumask_ipi);
return -ENOMEM;
}
@@ -59,6 +66,7 @@ int smpcfd_dead_cpu(unsigned int cpu)
struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
free_cpumask_var(cfd->cpumask);
+ free_cpumask_var(cfd->cpumask_ipi);
free_percpu(cfd->csd);
return 0;
}
@@ -428,12 +436,13 @@ void smp_call_function_many(const struct cpumask *mask,
cfd = this_cpu_ptr(&cfd_data);
cpumask_and(cfd->cpumask, mask, cpu_online_mask);
- cpumask_clear_cpu(this_cpu, cfd->cpumask);
+ __cpumask_clear_cpu(this_cpu, cfd->cpumask);
/* Some callers race with other cpus changing the passed mask */
if (unlikely(!cpumask_weight(cfd->cpumask)))
return;
+ cpumask_clear(cfd->cpumask_ipi);
for_each_cpu(cpu, cfd->cpumask) {
struct call_single_data *csd = per_cpu_ptr(cfd->csd, cpu);
@@ -442,11 +451,12 @@ void smp_call_function_many(const struct cpumask *mask,
csd->flags |= CSD_FLAG_SYNCHRONOUS;
csd->func = func;
csd->info = info;
- llist_add(&csd->llist, &per_cpu(call_single_queue, cpu));
+ if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)))
+ __cpumask_set_cpu(cpu, cfd->cpumask_ipi);
}
/* Send a message to all CPUs in the map */
- arch_send_call_function_ipi_mask(cfd->cpumask);
+ arch_send_call_function_ipi_mask(cfd->cpumask_ipi);
if (wait) {
for_each_cpu(cpu, cfd->cpumask) {
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 93621ae718d3..03918a19cf2d 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -233,6 +233,9 @@ static void clocksource_watchdog(unsigned long data)
continue;
}
+ if (cs == curr_clocksource && cs->tick_stable)
+ cs->tick_stable(cs);
+
if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
(cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
(watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 64c97fc130c4..db023e9cbb25 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -554,7 +554,7 @@ static void tick_nohz_stop_idle(struct tick_sched *ts, ktime_t now)
update_ts_time_stats(smp_processor_id(), ts, now, NULL);
ts->idle_active = 0;
- sched_clock_idle_wakeup_event(0);
+ sched_clock_idle_wakeup_event();
}
static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
@@ -782,8 +782,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
* the scheduler tick in nohz_restart_sched_tick.
*/
if (!ts->tick_stopped) {
- nohz_balance_enter_idle(cpu);
- calc_load_enter_idle();
+ calc_load_nohz_start();
cpu_load_update_nohz_start();
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
@@ -823,7 +822,7 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
*/
timer_clear_idle();
- calc_load_exit_idle();
+ calc_load_nohz_stop();
touch_softlockup_watchdog_sched();
/*
* Cancel the scheduled timer and restore the tick
@@ -923,8 +922,10 @@ static void __tick_nohz_idle_enter(struct tick_sched *ts)
ts->idle_expires = expires;
}
- if (!was_stopped && ts->tick_stopped)
+ if (!was_stopped && ts->tick_stopped) {
ts->idle_jiffies = ts->last_jiffies;
+ nohz_balance_enter_idle(cpu);
+ }
}
}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c74bf39ef764..a86688fabc55 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2864,11 +2864,11 @@ bool flush_work(struct work_struct *work)
EXPORT_SYMBOL_GPL(flush_work);
struct cwt_wait {
- wait_queue_t wait;
+ wait_queue_entry_t wait;
struct work_struct *work;
};
-static int cwt_wakefn(wait_queue_t *wait, unsigned mode, int sync, void *key)
+static int cwt_wakefn(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
{
struct cwt_wait *cwait = container_of(wait, struct cwt_wait, wait);