diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-07-22 13:41:54 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-08-14 11:53:02 +0200 |
| commit | 7fdba1ca10462f42ad2246b918fe6368f5ce488e (patch) | |
| tree | 6cdb2d8c57da4dde9df3aa22bd4839151884dba6 /arch/x86/kernel | |
| parent | bdc2209fd246820de2816691ac0e82600885e1a8 (diff) | |
perf, x86: Avoid kfree() in CPU_STARTING
On -rt kfree() can schedule, but CPU_STARTING is before the CPU is
fully up and running. These are contradictory, so avoid it. Instead
push the kfree() to CPU_ONLINE where we're free to schedule.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kwd4j6ayld5thrscvaxgjquv@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_amd.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 2 |
3 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 4ee3abf20ed6..594d42513e60 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -129,6 +129,8 @@ struct cpu_hw_events { * AMD specific bits */ struct amd_nb *amd_nb; + + void *kfree_on_online; }; #define __EVENT_CONSTRAINT(c, n, m, w) {\ @@ -1466,10 +1468,12 @@ static int __cpuinit x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) { unsigned int cpu = (long)hcpu; + struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); int ret = NOTIFY_OK; switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: + cpuc->kfree_on_online = NULL; if (x86_pmu.cpu_prepare) ret = x86_pmu.cpu_prepare(cpu); break; @@ -1479,6 +1483,10 @@ x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) x86_pmu.cpu_starting(cpu); break; + case CPU_ONLINE: + kfree(cpuc->kfree_on_online); + break; + case CPU_DYING: if (x86_pmu.cpu_dying) x86_pmu.cpu_dying(cpu); diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c index 941caa2e449b..ee9436c3e5d6 100644 --- a/arch/x86/kernel/cpu/perf_event_amd.c +++ b/arch/x86/kernel/cpu/perf_event_amd.c @@ -350,7 +350,7 @@ static void amd_pmu_cpu_starting(int cpu) continue; if (nb->nb_id == nb_id) { - kfree(cpuc->amd_nb); + cpuc->kfree_on_online = cpuc->amd_nb; cpuc->amd_nb = nb; break; } diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index f88af2c2a561..3751494e70f5 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1362,7 +1362,7 @@ static void intel_pmu_cpu_starting(int cpu) pc = per_cpu(cpu_hw_events, i).shared_regs; if (pc && pc->core_id == core_id) { - kfree(cpuc->shared_regs); + cpuc->kfree_on_online = cpuc->shared_regs; cpuc->shared_regs = pc; break; } |