perf: Fix perf_cgroup_switch for sw-events
Commit-ID: 95cf59ea72331d0093010543b8951bb43f262cac Gitweb: http://git.kernel.org/tip/95cf59ea72331d0093010543b8951bb43f262cac Author: Peter Zijlstra <[email protected]> AuthorDate: Tue, 2 Oct 2012 15:41:23 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 5 Oct 2012 13:59:07 +0200
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 <[email protected]>
Signed-off-by Peter Zijlstra <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
--- kernel/events/core.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)
kernel/events/core.c +6 -3
@@ -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);