Commit 95cf59ea authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

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: default avatarJiri Olsa <jolsa@redhat.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-so7wi2zf3jjzrwcutm2mkz0j@git.kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3f1f3320
...@@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode) ...@@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
list_for_each_entry_rcu(pmu, &pmus, entry) { list_for_each_entry_rcu(pmu, &pmus, entry) {
cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); 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 * perf_cgroup_events says at least one
...@@ -395,9 +397,10 @@ void perf_cgroup_switch(struct task_struct *task, int mode) ...@@ -395,9 +397,10 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
if (mode & PERF_CGROUP_SWIN) { if (mode & PERF_CGROUP_SWIN) {
WARN_ON_ONCE(cpuctx->cgrp); WARN_ON_ONCE(cpuctx->cgrp);
/* set cgrp before ctxsw in to /*
* allow event_filter_match() to not * set cgrp before ctxsw in to allow
* have to pass task around * event_filter_match() to not have to pass
* task around
*/ */
cpuctx->cgrp = perf_cgroup_from_task(task); cpuctx->cgrp = perf_cgroup_from_task(task);
cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
......
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