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| author | Peter Zijlstra <peterz@infradead.org> | 2016-01-08 09:21:40 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-01-21 18:54:19 +0100 |
| commit | 7e41d17753e6e0da55d343997454dd4fbe8d28a8 (patch) | |
| tree | 1fb4b3d63f54aff3f54dd008f111ba0631e52a1e | |
| parent | c994d6136738fd8b24a79f5ad8df40a6a79e2cf7 (diff) | |
| download | linux-7e41d17753e6e0da55d343997454dd4fbe8d28a8.tar.gz linux-7e41d17753e6e0da55d343997454dd4fbe8d28a8.tar.bz2 linux-7e41d17753e6e0da55d343997454dd4fbe8d28a8.zip | |
perf: Fix cgroup event scheduling
There appears to be a problem in __perf_event_task_sched_in() wrt
cgroup event scheduling.
The normal event scheduling order is:
CPU pinned
Task pinned
CPU flexible
Task flexible
And since perf_cgroup_sched*() only schedules the cpu context, we must
call this _before_ adding the task events.
Note: double check what happens on the ctx switch optimization where
the task ctx isn't scheduled.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/events/core.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c77b05d9a37d..9d1195af819c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2806,6 +2806,16 @@ void __perf_event_task_sched_in(struct task_struct *prev, struct perf_event_context *ctx; int ctxn; + /* + * If cgroup events exist on this CPU, then we need to check if we have + * to switch in PMU state; cgroup event are system-wide mode only. + * + * Since cgroup events are CPU events, we must schedule these in before + * we schedule in the task events. + */ + if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) + perf_cgroup_sched_in(prev, task); + for_each_task_context_nr(ctxn) { ctx = task->perf_event_ctxp[ctxn]; if (likely(!ctx)) @@ -2813,13 +2823,6 @@ void __perf_event_task_sched_in(struct task_struct *prev, perf_event_context_sched_in(ctx, task); } - /* - * if cgroup events exist on this CPU, then we need - * to check if we have to switch in PMU state. - * cgroup event are system-wide mode only - */ - if (atomic_read(this_cpu_ptr(&perf_cgroup_events))) - perf_cgroup_sched_in(prev, task); if (atomic_read(&nr_switch_events)) perf_event_switch(task, prev, true); |