From: Peter Zijlstra Date: Tue, 2 Oct 2012 13:41:23 +0000 (+0200) Subject: perf: Fix perf_cgroup_switch for sw-events X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=95cf59ea72331d0093010543b8951bb43f262cac;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git perf: Fix perf_cgroup_switch for sw-events Jiri reported that he could trigger the WARN_ON_ONCE() in perf_cgroup_switch() using sw-events. This is because sw-events share a cpuctx with multiple PMUs. Use the ->unique_pmu pointer to limit the pmu iteration to unique cpuctx instances. Reported-and-Tested-by: Jiri Olsa Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-so7wi2zf3jjzrwcutm2mkz0j@git.kernel.org Signed-off-by: Ingo Molnar --- diff --git a/kernel/events/core.c b/kernel/events/core.c index 81939e8999a5..fd15593c7f54 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode) list_for_each_entry_rcu(pmu, &pmus, entry) { cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); + if (cpuctx->unique_pmu != pmu) + continue; /* ensure we process each cpuctx once */ /* * perf_cgroup_events says at least one @@ -395,9 +397,10 @@ void perf_cgroup_switch(struct task_struct *task, int mode) if (mode & PERF_CGROUP_SWIN) { WARN_ON_ONCE(cpuctx->cgrp); - /* set cgrp before ctxsw in to - * allow event_filter_match() to not - * have to pass task around + /* + * set cgrp before ctxsw in to allow + * event_filter_match() to not have to pass + * task around */ cpuctx->cgrp = perf_cgroup_from_task(task); cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);