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authorLinus Torvalds <torvalds@linux-foundation.org>2011-11-03 07:44:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-03 07:44:04 -0700
commit4536e4d1d21c8172402a2217b0fa1880665ace36 (patch)
tree0bcf19fda146cb4afbdd6487218fb6ac16b80fcd
parent43672a0784707d795556b1f93925da8b8e797d03 (diff)
Revert "perf: Add PM notifiers to fix CPU hotplug races"
This reverts commit 144060fee07e9c22e179d00819c83c86fbcbf82c. It causes a resume regression for Andi on his Acer Aspire 1830T post 3.1. The screen just stays black after wakeup. Also, it really looks like the wrong way to suspend and resume perf events: I think they should be done as part of the CPU suspend and resume, rather than as a notifier that does smp_call_function(). Reported-by: Andi Kleen <andi@firstfloor.org> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/events/core.c97
1 files changed, 2 insertions, 95 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 12a0287e0358..e1253faa34dd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -29,7 +29,6 @@
#include <linux/hardirq.h>
#include <linux/rculist.h>
#include <linux/uaccess.h>
-#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/anon_inodes.h>
#include <linux/kernel_stat.h>
@@ -6853,7 +6852,7 @@ static void __cpuinit perf_event_init_cpu(int cpu)
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
- if (swhash->hlist_refcount > 0 && !swhash->swevent_hlist) {
+ if (swhash->hlist_refcount > 0) {
struct swevent_hlist *hlist;
hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
@@ -6942,14 +6941,7 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
{
unsigned int cpu = (long)hcpu;
- /*
- * Ignore suspend/resume action, the perf_pm_notifier will
- * take care of that.
- */
- if (action & CPU_TASKS_FROZEN)
- return NOTIFY_OK;
-
- switch (action) {
+ switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
case CPU_DOWN_FAILED:
@@ -6968,90 +6960,6 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
return NOTIFY_OK;
}
-static void perf_pm_resume_cpu(void *unused)
-{
- struct perf_cpu_context *cpuctx;
- struct perf_event_context *ctx;
- struct pmu *pmu;
- int idx;
-
- idx = srcu_read_lock(&pmus_srcu);
- list_for_each_entry_rcu(pmu, &pmus, entry) {
- cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
- ctx = cpuctx->task_ctx;
-
- perf_ctx_lock(cpuctx, ctx);
- perf_pmu_disable(cpuctx->ctx.pmu);
-
- cpu_ctx_sched_out(cpuctx, EVENT_ALL);
- if (ctx)
- ctx_sched_out(ctx, cpuctx, EVENT_ALL);
-
- perf_pmu_enable(cpuctx->ctx.pmu);
- perf_ctx_unlock(cpuctx, ctx);
- }
- srcu_read_unlock(&pmus_srcu, idx);
-}
-
-static void perf_pm_suspend_cpu(void *unused)
-{
- struct perf_cpu_context *cpuctx;
- struct perf_event_context *ctx;
- struct pmu *pmu;
- int idx;
-
- idx = srcu_read_lock(&pmus_srcu);
- list_for_each_entry_rcu(pmu, &pmus, entry) {
- cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
- ctx = cpuctx->task_ctx;
-
- perf_ctx_lock(cpuctx, ctx);
- perf_pmu_disable(cpuctx->ctx.pmu);
-
- perf_event_sched_in(cpuctx, ctx, current);
-
- perf_pmu_enable(cpuctx->ctx.pmu);
- perf_ctx_unlock(cpuctx, ctx);
- }
- srcu_read_unlock(&pmus_srcu, idx);
-}
-
-static int perf_resume(void)
-{
- get_online_cpus();
- smp_call_function(perf_pm_resume_cpu, NULL, 1);
- put_online_cpus();
-
- return NOTIFY_OK;
-}
-
-static int perf_suspend(void)
-{
- get_online_cpus();
- smp_call_function(perf_pm_suspend_cpu, NULL, 1);
- put_online_cpus();
-
- return NOTIFY_OK;
-}
-
-static int perf_pm(struct notifier_block *self, unsigned long action, void *ptr)
-{
- switch (action) {
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
- return perf_resume();
- case PM_HIBERNATION_PREPARE:
- case PM_SUSPEND_PREPARE:
- return perf_suspend();
- default:
- return NOTIFY_DONE;
- }
-}
-
-static struct notifier_block perf_pm_notifier = {
- .notifier_call = perf_pm,
-};
-
void __init perf_event_init(void)
{
int ret;
@@ -7066,7 +6974,6 @@ void __init perf_event_init(void)
perf_tp_register();
perf_cpu_notifier(perf_cpu_notify);
register_reboot_notifier(&perf_reboot_notifier);
- register_pm_notifier(&perf_pm_notifier);
ret = init_hw_breakpoint();
WARN(ret, "hw_breakpoint initialization failed with: %d", ret);