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authorLinus Torvalds <torvalds@linux-foundation.org>2016-07-29 13:55:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-29 13:55:30 -0700
commita6408f6cb63ac0958fee7dbce7861ffb540d8a49 (patch)
treec94a835d343974171951e3b805e6bbbb02852ebc /kernel
parent1a81a8f2a5918956e214bb718099a89e500e7ec5 (diff)
parent4fae16dffb812f0e0d98a0b2b0856ca48ca63e6c (diff)
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner: "This is the next part of the hotplug rework. - Convert all notifiers with a priority assigned - Convert all CPU_STARTING/DYING notifiers The final removal of the STARTING/DYING infrastructure will happen when the merge window closes. Another 700 hundred line of unpenetrable maze gone :)" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) timers/core: Correct callback order during CPU hot plug leds/trigger/cpu: Move from CPU_STARTING to ONLINE level powerpc/numa: Convert to hotplug state machine arm/perf: Fix hotplug state machine conversion irqchip/armada: Avoid unused function warnings ARC/time: Convert to hotplug state machine clocksource/atlas7: Convert to hotplug state machine clocksource/armada-370-xp: Convert to hotplug state machine clocksource/exynos_mct: Convert to hotplug state machine clocksource/arm_global_timer: Convert to hotplug state machine rcu: Convert rcutree to hotplug state machine KVM/arm/arm64/vgic-new: Convert to hotplug state machine smp/cfd: Convert core to hotplug state machine x86/x2apic: Convert to CPU hotplug state machine profile: Convert to hotplug state machine timers/core: Convert to hotplug state machine hrtimer: Convert to hotplug state machine x86/tboot: Convert to hotplug state machine arm64/armv8 deprecated: Convert to hotplug state machine hwtracing/coresight-etm4x: Convert to hotplug state machine ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c66
-rw-r--r--kernel/events/core.c56
-rw-r--r--kernel/profile.c181
-rw-r--r--kernel/rcu/tree.c105
-rw-r--r--kernel/smp.c79
-rw-r--r--kernel/time/hrtimer.c40
-rw-r--r--kernel/time/timer.c25
-rw-r--r--kernel/workqueue.c108
8 files changed, 275 insertions, 385 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7b61887f7ccd..341bf80f80bd 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -517,6 +517,13 @@ static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state,
if (!cpu_online(cpu))
return 0;
+ /*
+ * If we are up and running, use the hotplug thread. For early calls
+ * we invoke the thread function directly.
+ */
+ if (!st->thread)
+ return cpuhp_invoke_callback(cpu, state, cb);
+
st->cb_state = state;
st->cb = cb;
/*
@@ -1173,6 +1180,31 @@ static struct cpuhp_step cpuhp_bp_states[] = {
.teardown = NULL,
.cant_stop = true,
},
+ [CPUHP_PERF_PREPARE] = {
+ .name = "perf prepare",
+ .startup = perf_event_init_cpu,
+ .teardown = perf_event_exit_cpu,
+ },
+ [CPUHP_WORKQUEUE_PREP] = {
+ .name = "workqueue prepare",
+ .startup = workqueue_prepare_cpu,
+ .teardown = NULL,
+ },
+ [CPUHP_HRTIMERS_PREPARE] = {
+ .name = "hrtimers prepare",
+ .startup = hrtimers_prepare_cpu,
+ .teardown = hrtimers_dead_cpu,
+ },
+ [CPUHP_SMPCFD_PREPARE] = {
+ .name = "SMPCFD prepare",
+ .startup = smpcfd_prepare_cpu,
+ .teardown = smpcfd_dead_cpu,
+ },
+ [CPUHP_RCUTREE_PREP] = {
+ .name = "RCU-tree prepare",
+ .startup = rcutree_prepare_cpu,
+ .teardown = rcutree_dead_cpu,
+ },
/*
* Preparatory and dead notifiers. Will be replaced once the notifiers
* are converted to states.
@@ -1184,6 +1216,16 @@ static struct cpuhp_step cpuhp_bp_states[] = {
.skip_onerr = true,
.cant_stop = true,
},
+ /*
+ * On the tear-down path, timers_dead_cpu() must be invoked
+ * before blk_mq_queue_reinit_notify() from notify_dead(),
+ * otherwise a RCU stall occurs.
+ */
+ [CPUHP_TIMERS_DEAD] = {
+ .name = "timers dead",
+ .startup = NULL,
+ .teardown = timers_dead_cpu,
+ },
/* Kicks the plugged cpu into life */
[CPUHP_BRINGUP_CPU] = {
.name = "cpu:bringup",
@@ -1191,6 +1233,10 @@ static struct cpuhp_step cpuhp_bp_states[] = {
.teardown = NULL,
.cant_stop = true,
},
+ [CPUHP_AP_SMPCFD_DYING] = {
+ .startup = NULL,
+ .teardown = smpcfd_dying_cpu,
+ },
/*
* Handled on controll processor until the plugged processor manages
* this itself.
@@ -1227,6 +1273,10 @@ static struct cpuhp_step cpuhp_ap_states[] = {
.startup = sched_cpu_starting,
.teardown = sched_cpu_dying,
},
+ [CPUHP_AP_RCUTREE_DYING] = {
+ .startup = NULL,
+ .teardown = rcutree_dying_cpu,
+ },
/*
* Low level startup/teardown notifiers. Run with interrupts
* disabled. Will be removed once the notifiers are converted to
@@ -1250,6 +1300,22 @@ static struct cpuhp_step cpuhp_ap_states[] = {
.startup = smpboot_unpark_threads,
.teardown = NULL,
},
+ [CPUHP_AP_PERF_ONLINE] = {
+ .name = "perf online",
+ .startup = perf_event_init_cpu,
+ .teardown = perf_event_exit_cpu,
+ },
+ [CPUHP_AP_WORKQUEUE_ONLINE] = {
+ .name = "workqueue online",
+ .startup = workqueue_online_cpu,
+ .teardown = workqueue_offline_cpu,
+ },
+ [CPUHP_AP_RCUTREE_ONLINE] = {
+ .name = "RCU-tree online",
+ .startup = rcutree_online_cpu,
+ .teardown = rcutree_offline_cpu,
+ },
+
/*
* Online/down_prepare notifiers. Will be removed once the notifiers
* are converted to states.
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 09ae27b353c1..356a6c7cb52a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10357,7 +10357,7 @@ static void __init perf_event_init_all_cpus(void)
}
}
-static void perf_event_init_cpu(int cpu)
+int perf_event_init_cpu(unsigned int cpu)
{
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
@@ -10370,6 +10370,7 @@ static void perf_event_init_cpu(int cpu)
rcu_assign_pointer(swhash->swevent_hlist, hlist);
}
mutex_unlock(&swhash->hlist_mutex);
+ return 0;
}
#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
@@ -10401,14 +10402,17 @@ static void perf_event_exit_cpu_context(int cpu)
}
srcu_read_unlock(&pmus_srcu, idx);
}
+#else
+
+static void perf_event_exit_cpu_context(int cpu) { }
+
+#endif
-static void perf_event_exit_cpu(int cpu)
+int perf_event_exit_cpu(unsigned int cpu)
{
perf_event_exit_cpu_context(cpu);
+ return 0;
}
-#else
-static inline void perf_event_exit_cpu(int cpu) { }
-#endif
static int
perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
@@ -10430,46 +10434,6 @@ static struct notifier_block perf_reboot_notifier = {
.priority = INT_MIN,
};
-static int
-perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
- unsigned int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
-
- case CPU_UP_PREPARE:
- /*
- * This must be done before the CPU comes alive, because the
- * moment we can run tasks we can encounter (software) events.
- *
- * Specifically, someone can have inherited events on kthreadd
- * or a pre-existing worker thread that gets re-bound.
- */
- perf_event_init_cpu(cpu);
- break;
-
- case CPU_DOWN_PREPARE:
- /*
- * This must be done before the CPU dies because after that an
- * active event might want to IPI the CPU and that'll not work
- * so great for dead CPUs.
- *
- * XXX smp_call_function_single() return -ENXIO without a warn
- * so we could possibly deal with this.
- *
- * This is safe against new events arriving because
- * sys_perf_event_open() serializes against hotplug using
- * get_online_cpus().
- */
- perf_event_exit_cpu(cpu);
- break;
- default:
- break;
- }
-
- return NOTIFY_OK;
-}
-
void __init perf_event_init(void)
{
int ret;
@@ -10482,7 +10446,7 @@ void __init perf_event_init(void)
perf_pmu_register(&perf_cpu_clock, NULL, -1);
perf_pmu_register(&perf_task_clock, NULL, -1);
perf_tp_register();
- perf_cpu_notifier(perf_cpu_notify);
+ perf_event_init_cpu(smp_processor_id());
register_reboot_notifier(&perf_reboot_notifier);
ret = init_hw_breakpoint();
diff --git a/kernel/profile.c b/kernel/profile.c
index c2199e9901c9..2dbccf2d806c 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -328,68 +328,57 @@ out:
put_cpu();
}
-static int profile_cpu_callback(struct notifier_block *info,
- unsigned long action, void *__cpu)
+static int profile_dead_cpu(unsigned int cpu)
{
- int node, cpu = (unsigned long)__cpu;
struct page *page;
+ int i;
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- node = cpu_to_mem(cpu);
- per_cpu(cpu_profile_flip, cpu) = 0;
- if (!per_cpu(cpu_profile_hits, cpu)[1]) {
- page = __alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO,
- 0);
- if (!page)
- return notifier_from_errno(-ENOMEM);
- per_cpu(cpu_profile_hits, cpu)[1] = page_address(page);
- }
- if (!per_cpu(cpu_profile_hits, cpu)[0]) {
- page = __alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO,
- 0);
- if (!page)
- goto out_free;
- per_cpu(cpu_profile_hits, cpu)[0] = page_address(page);
- }
- break;
-out_free:
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
- return notifier_from_errno(-ENOMEM);
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- if (prof_cpu_mask != NULL)
- cpumask_set_cpu(cpu, prof_cpu_mask);
- break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- if (prof_cpu_mask != NULL)
- cpumask_clear_cpu(cpu, prof_cpu_mask);
- if (per_cpu(cpu_profile_hits, cpu)[0]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
- per_cpu(cpu_profile_hits, cpu)[0] = NULL;
+ if (prof_cpu_mask != NULL)
+ cpumask_clear_cpu(cpu, prof_cpu_mask);
+
+ for (i = 0; i < 2; i++) {
+ if (per_cpu(cpu_profile_hits, cpu)[i]) {
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]);
+ per_cpu(cpu_profile_hits, cpu)[i] = NULL;
__free_page(page);
}
- if (per_cpu(cpu_profile_hits, cpu)[1]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
+ }
+ return 0;
+}
+
+static int profile_prepare_cpu(unsigned int cpu)
+{
+ int i, node = cpu_to_mem(cpu);
+ struct page *page;
+
+ per_cpu(cpu_profile_flip, cpu) = 0;
+
+ for (i = 0; i < 2; i++) {
+ if (per_cpu(cpu_profile_hits, cpu)[i])
+ continue;
+
+ page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
+ if (!page) {
+ profile_dead_cpu(cpu);
+ return -ENOMEM;
}
- break;
+ per_cpu(cpu_profile_hits, cpu)[i] = page_address(page);
+
}
- return NOTIFY_OK;
+ return 0;
+}
+
+static int profile_online_cpu(unsigned int cpu)
+{
+ if (prof_cpu_mask != NULL)
+ cpumask_set_cpu(cpu, prof_cpu_mask);
+
+ return 0;
}
+
#else /* !CONFIG_SMP */
#define profile_flip_buffers() do { } while (0)
#define profile_discard_flip_buffers() do { } while (0)
-#define profile_cpu_callback NULL
static void do_profile_hits(int type, void *__pc, unsigned int nr_hits)
{
@@ -531,83 +520,43 @@ static const struct file_operations proc_profile_operations = {
.llseek = default_llseek,
};
-#ifdef CONFIG_SMP
-static void profile_nop(void *unused)
-{
-}
-
-static int create_hash_tables(void)
+int __ref create_proc_profile(void)
{
- int cpu;
-
- for_each_online_cpu(cpu) {
- int node = cpu_to_mem(cpu);
- struct page *page;
-
- page = __alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
- 0);
- if (!page)
- goto out_cleanup;
- per_cpu(cpu_profile_hits, cpu)[1]
- = (struct profile_hit *)page_address(page);
- page = __alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
- 0);
- if (!page)
- goto out_cleanup;
- per_cpu(cpu_profile_hits, cpu)[0]
- = (struct profile_hit *)page_address(page);
- }
- return 0;
-out_cleanup:
- prof_on = 0;
- smp_mb();
- on_each_cpu(profile_nop, NULL, 1);
- for_each_online_cpu(cpu) {
- struct page *page;
-
- if (per_cpu(cpu_profile_hits, cpu)[0]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
- per_cpu(cpu_profile_hits, cpu)[0] = NULL;
- __free_page(page);
- }
- if (per_cpu(cpu_profile_hits, cpu)[1]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
- }
- }
- return -1;
-}
-#else
-#define create_hash_tables() ({ 0; })
+ struct proc_dir_entry *entry;
+#ifdef CONFIG_SMP
+ enum cpuhp_state online_state;
#endif
-int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */
-{
- struct proc_dir_entry *entry;
int err = 0;
if (!prof_on)
return 0;
-
- cpu_notifier_register_begin();
-
- if (create_hash_tables()) {
- err = -ENOMEM;
- goto out;
- }
-
+#ifdef CONFIG_SMP
+ err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE",
+ profile_prepare_cpu, profile_dead_cpu);
+ if (err)
+ return err;
+
+ err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PROFILE_ONLINE",
+ profile_online_cpu, NULL);
+ if (err < 0)
+ goto err_state_prep;
+ online_state = err;
+ err = 0;
+#endif
entry = proc_create("profile", S_IWUSR | S_IRUGO,
NULL, &proc_profile_operations);
if (!entry)
- goto out;
+ goto err_state_onl;
proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t));
- __hotcpu_notifier(profile_cpu_callback, 0);
-out:
- cpu_notifier_register_done();
+ return err;
+err_state_onl:
+#ifdef CONFIG_SMP
+ cpuhp_remove_state(online_state);
+err_state_prep:
+ cpuhp_remove_state(CPUHP_PROFILE_PREPARE);
+#endif
return err;
}
subsys_initcall(create_proc_profile);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f433959e9322..5d80925e7fc8 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1073,11 +1073,11 @@ EXPORT_SYMBOL_GPL(rcu_is_watching);
* offline to continue to use RCU for one jiffy after marking itself
* offline in the cpu_online_mask. This leniency is necessary given the
* non-atomic nature of the online and offline processing, for example,
- * the fact that a CPU enters the scheduler after completing the CPU_DYING
- * notifiers.
+ * the fact that a CPU enters the scheduler after completing the teardown
+ * of the CPU.
*
- * This is also why RCU internally marks CPUs online during the
- * CPU_UP_PREPARE phase and offline during the CPU_DEAD phase.
+ * This is also why RCU internally marks CPUs online during in the
+ * preparation phase and offline after the CPU has been taken down.
*
* Disable checking if in an NMI handler because we cannot safely report
* errors from NMI handlers anyway.
@@ -3806,12 +3806,58 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
-static void rcu_prepare_cpu(int cpu)
+int rcutree_prepare_cpu(unsigned int cpu)
{
struct rcu_state *rsp;
for_each_rcu_flavor(rsp)
rcu_init_percpu_data(cpu, rsp);
+
+ rcu_prepare_kthreads(cpu);
+ rcu_spawn_all_nocb_kthreads(cpu);
+
+ return 0;
+}
+
+static void rcutree_affinity_setting(unsigned int cpu, int outgoing)
+{
+ struct rcu_data *rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
+
+ rcu_boost_kthread_setaffinity(rdp->mynode, outgoing);
+}
+
+int rcutree_online_cpu(unsigned int cpu)
+{
+ sync_sched_exp_online_cleanup(cpu);
+ rcutree_affinity_setting(cpu, -1);
+ return 0;
+}
+
+int rcutree_offline_cpu(unsigned int cpu)
+{
+ rcutree_affinity_setting(cpu, cpu);
+ return 0;
+}
+
+
+int rcutree_dying_cpu(unsigned int cpu)
+{
+ struct rcu_state *rsp;
+
+ for_each_rcu_flavor(rsp)
+ rcu_cleanup_dying_cpu(rsp);
+ return 0;
+}
+
+int rcutree_dead_cpu(unsigned int cpu)
+{
+ struct rcu_state *rsp;
+
+ for_each_rcu_flavor(rsp) {
+ rcu_cleanup_dead_cpu(cpu, rsp);
+ do_nocb_deferred_wakeup(per_cpu_ptr(rsp->rda, cpu));
+ }
+ return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -3851,52 +3897,6 @@ void rcu_report_dead(unsigned int cpu)
}
#endif
-/*
- * Handle CPU online/offline notification events.
- */
-int rcu_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- long cpu = (long)hcpu;
- struct rcu_data *rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
- struct rcu_node *rnp = rdp->mynode;
- struct rcu_state *rsp;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- rcu_prepare_cpu(cpu);
- rcu_prepare_kthreads(cpu);
- rcu_spawn_all_nocb_kthreads(cpu);
- break;
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- sync_sched_exp_online_cleanup(cpu);
- rcu_boost_kthread_setaffinity(rnp, -1);
- break;
- case CPU_DOWN_PREPARE:
- rcu_boost_kthread_setaffinity(rnp, cpu);
- break;
- case CPU_DYING:
- case CPU_DYING_FROZEN:
- for_each_rcu_flavor(rsp)
- rcu_cleanup_dying_cpu(rsp);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- for_each_rcu_flavor(rsp) {
- rcu_cleanup_dead_cpu(cpu, rsp);
- do_nocb_deferred_wakeup(per_cpu_ptr(rsp->rda, cpu));
- }
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
static int rcu_pm_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
@@ -4208,10 +4208,9 @@ void __init rcu_init(void)
* this is called early in boot, before either interrupts
* or the scheduler are operational.
*/
- cpu_notifier(rcu_cpu_notify, 0);
pm_notifier(rcu_pm_notify, 0);
for_each_online_cpu(cpu)
- rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
+ rcutree_prepare_cpu(cpu);
}
#include "tree_exp.h"
diff --git a/kernel/smp.c b/kernel/smp.c
index 36552beed397..3aa642d39c03 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -33,69 +33,54 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue);
static void flush_smp_call_function_queue(bool warn_cpu_offline);
-static int
-hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
+int smpcfd_prepare_cpu(unsigned int cpu)
{
- long cpu = (long)hcpu;
struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
- cpu_to_node(cpu)))
- return notifier_from_errno(-ENOMEM);
- cfd->csd = alloc_percpu(struct call_single_data);
- if (!cfd->csd) {
- free_cpumask_var(cfd->cpumask);
- return notifier_from_errno(-ENOMEM);
- }
- break;
-
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- /* Fall-through to the CPU_DEAD[_FROZEN] case. */
-
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
+ if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
+ cpu_to_node(cpu)))
+ return -ENOMEM;
+ cfd->csd = alloc_percpu(struct call_single_data);
+ if (!cfd->csd) {
free_cpumask_var(cfd->cpumask);
- free_percpu(cfd->csd);
- break;
+ return -ENOMEM;
+ }
- case CPU_DYING:
- case CPU_DYING_FROZEN:
- /*
- * The IPIs for the smp-call-function callbacks queued by other
- * CPUs might arrive late, either due to hardware latencies or
- * because this CPU disabled interrupts (inside stop-machine)
- * before the IPIs were sent. So flush out any pending callbacks
- * explicitly (without waiting for the IPIs to arrive), to
- * ensure that the outgoing CPU doesn't go offline with work
- * still pending.
- */
- flush_smp_call_function_queue(false);
- break;
-#endif
- };
+ return 0;
+}
+
+int smpcfd_dead_cpu(unsigned int cpu)
+{
+ struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
- return NOTIFY_OK;
+ free_cpumask_var(cfd->cpumask);
+ free_percpu(cfd->csd);
+ return 0;
}
-static struct notifier_block hotplug_cfd_notifier = {
- .notifier_call = hotplug_cfd,
-};
+int smpcfd_dying_cpu(unsigned int cpu)
+{
+ /*
+ * The IPIs for the smp-call-function callbacks queued by other
+ * CPUs might arrive late, either due to hardware latencies or
+ * because this CPU disabled interrupts (inside stop-machine)
+ * before the IPIs were sent. So flush out any pending callbacks
+ * explicitly (without waiting for the IPIs to arrive), to
+ * ensure that the outgoing CPU doesn't go offline with work
+ * still pending.
+ */
+ flush_smp_call_function_queue(false);
+ return 0;
+}
void __init call_function_init(void)
{
- void *cpu = (void *)(long)smp_processor_id();
int i;
for_each_possible_cpu(i)
init_llist_head(&per_cpu(call_single_queue, i));
- hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
- register_cpu_notifier(&hotplug_cfd_notifier);
+ smpcfd_prepare_cpu(smp_processor_id());
}
/*
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d13c9aebf7a3..9ba7c820fc23 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1590,7 +1590,7 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
/*
* Functions related to boot-time initialization:
*/
-static void init_hrtimers_cpu(int cpu)
+int hrtimers_prepare_cpu(unsigned int cpu)
{
struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
int i;
@@ -1602,6 +1602,7 @@ static void init_hrtimers_cpu(int cpu)
cpu_base->cpu = cpu;
hrtimer_init_hres(cpu_base);
+ return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -1636,7 +1637,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
}
}
-static void migrate_hrtimers(int scpu)
+int hrtimers_dead_cpu(unsigned int scpu)
{
struct hrtimer_cpu_base *old_base, *new_base;
int i;
@@ -1665,45 +1666,14 @@ static void migrate_hrtimers(int scpu)
/* Check, if we got expired work to do */
__hrtimer_peek_ahead_timers();
local_irq_enable();
+ return 0;
}
#endif /* CONFIG_HOTPLUG_CPU */
-static int hrtimer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int scpu = (long)hcpu;
-
- switch (action) {
-
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- init_hrtimers_cpu(scpu);
- break;
-
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- migrate_hrtimers(scpu);
- break;
-#endif
-
- default:
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block hrtimers_nb = {
- .notifier_call = hrtimer_cpu_notify,
-};
-
void __init hrtimers_init(void)
{
- hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
- (void *)(long)smp_processor_id());
- register_cpu_notifier(&hrtimers_nb);
+ hrtimers_prepare_cpu(smp_processor_id());
}
/**
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index cb9ab401e2d9..555670a5143c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1804,7 +1804,7 @@ static void migrate_timer_list(struct timer_base *new_base, struct hlist_head *h
}
}
-static void migrate_timers(int cpu)
+int timers_dead_cpu(unsigned int cpu)
{
struct timer_base *old_base;
struct timer_base *new_base;
@@ -1831,29 +1831,9 @@ static void migrate_timers(int cpu)
spin_unlock_irq(&new_base->lock);
put_cpu_ptr(&timer_bases);
}
+ return 0;
}
-static int timer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- switch (action) {
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- migrate_timers((long)hcpu);
- break;
- default:
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static inline void timer_register_cpu_notifier(void)
-{
- cpu_notifier(timer_cpu_notify, 0);
-}
-#else
-static inline void timer_register_cpu_notifier(void) { }
#endif /* CONFIG_HOTPLUG_CPU */
static void __init init_timer_cpu(int cpu)
@@ -1881,7 +1861,6 @@ void __init init_timers(void)
{
init_timer_cpus();
init_timer_stats();
- timer_register_cpu_notifier();
open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d12bd958077e..ef071ca73fc3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4607,84 +4607,65 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu)
WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, &cpumask) < 0);
}
-/*
- * Workqueues should be brought up before normal priority CPU notifiers.
- * This will be registered high priority CPU notifier.
- */
-static int workqueue_cpu_up_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+int workqueue_prepare_cpu(unsigned int cpu)
+{
+ struct worker_pool *pool;
+
+ for_each_cpu_worker_pool(pool, cpu) {
+ if (pool->nr_workers)
+ continue;
+ if (!create_worker(pool))
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+int workqueue_online_cpu(unsigned int cpu)
{
- int cpu = (unsigned long)hcpu;
struct worker_pool *pool;
struct workqueue_struct *wq;
int pi;
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_UP_PREPARE:
- for_each_cpu_worker_pool(pool, cpu) {
- if (pool->nr_workers)
- continue;
- if (!create_worker(pool))
- return NOTIFY_BAD;
- }
- break;
-
- case CPU_DOWN_FAILED:
- case CPU_ONLINE:
- mutex_lock(&wq_pool_mutex);
+ mutex_lock(&wq_pool_mutex);
- for_each_pool(pool, pi) {
- mutex_lock(&pool->attach_mutex);
+ for_each_pool(pool, pi) {
+ mutex_lock(&pool->attach_mutex);
- if (pool->cpu == cpu)
- rebind_workers(pool);
- else if (pool->cpu < 0)
- restore_unbound_workers_cpumask(pool, cpu);
+ if (pool->cpu == cpu)
+ rebind_workers(pool);
+ else if (pool->cpu < 0)
+ restore_unbound_workers_cpumask(pool, cpu);
- mutex_unlock(&pool->attach_mutex);
- }
+ mutex_unlock(&pool->attach_mutex);
+ }
- /* update NUMA affinity of unbound workqueues */
- list_for_each_entry(wq, &workqueues, list)
- wq_update_unbound_numa(wq, cpu, true);
+ /* update NUMA affinity of unbound workqueues */
+ list_for_each_entry(wq, &workqueues, list)
+ wq_update_unbound_numa(wq, cpu, true);
- mutex_unlock(&wq_pool_mutex);
- break;
- }
- return NOTIFY_OK;
+ mutex_unlock(&wq_pool_mutex);
+ return 0;
}
-/*
- * Workqueues should be brought down after normal priority CPU notifiers.
- * This will be registered as low priority CPU notifier.
- */
-static int workqueue_cpu_down_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+int workqueue_offline_cpu(unsigned int cpu)
{
- int cpu = (unsigned long)hcpu;
struct work_struct unbind_work;
struct workqueue_struct *wq;
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- /* unbinding per-cpu workers should happen on the local CPU */
- INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
- queue_work_on(cpu, system_highpri_wq, &unbind_work);
-
- /* update NUMA affinity of unbound workqueues */
- mutex_lock(&wq_pool_mutex);
- list_for_each_entry(wq, &workqueues, list)
- wq_update_unbound_numa(wq, cpu, false);
- mutex_unlock(&wq_pool_mutex);
-
- /* wait for per-cpu unbinding to finish */
- flush_work(&unbind_work);
- destroy_work_on_stack(&unbind_work);
- break;
- }
- return NOTIFY_OK;
+ /* unbinding per-cpu workers should happen on the local CPU */
+ INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
+ queue_work_on(cpu, system_highpri_wq, &unbind_work);
+
+ /* update NUMA affinity of unbound workqueues */
+ mutex_lock(&wq_pool_mutex);
+ list_for_each_entry(wq, &workqueues, list)
+ wq_update_unbound_numa(wq, cpu, false);
+ mutex_unlock(&wq_pool_mutex);
+
+ /* wait for per-cpu unbinding to finish */
+ flush_work(&unbind_work);
+ destroy_work_on_stack(&unbind_work);
+ return 0;
}
#ifdef CONFIG_SMP
@@ -5486,9 +5467,6 @@ static int __init init_workqueues(void)
pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
- cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
- hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
-
wq_numa_init();
/* initialize CPU pools */