From 0f722a400afccaa0fac2ff010ba337ba428bd78b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 2 Oct 2012 15:41:23 +0200 Subject: perf: Fix perf_cgroup_switch for sw-events commit 95cf59ea72331d0093010543b8951bb43f262cac upstream. 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 Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/events/core.c b/kernel/events/core.c index a3d53ac..acdc087 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -342,6 +342,8 @@ 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_pmu_disable(cpuctx->ctx.pmu); @@ -365,9 +367,10 @@ 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); -- cgit v1.1