diff options
| author | Ian Rogers <irogers@google.com> | 2019-06-01 11:27:22 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-06-24 20:30:04 +0300 |
| commit | fd7d55172d1e2e501e6da0a5c1de25f06612dc2e (patch) | |
| tree | 4521b1d53d01c694a8f7b20254ff893b49b8a151 /include/linux/perf_event.h | |
| parent | 637d97b53cdded02da55d0a25cda6fd6af3bd042 (diff) | |
| download | linux-fd7d55172d1e2e501e6da0a5c1de25f06612dc2e.tar.xz | |
perf/cgroups: Don't rotate events for cgroups unnecessarily
Currently perf_rotate_context assumes that if the context's nr_events !=
nr_active a rotation is necessary for perf event multiplexing. With
cgroups, nr_events is the total count of events for all cgroups and
nr_active will not include events in a cgroup other than the current
task's. This makes rotation appear necessary for cgroups when it is not.
Add a perf_event_context flag that is set when rotation is necessary.
Clear the flag during sched_out and set it when a flexible sched_in
fails due to resources.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.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>
Link: https://lkml.kernel.org/r/20190601082722.44543-1-irogers@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/perf_event.h')
| -rw-r--r-- | include/linux/perf_event.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 3dc01cf98e16..2ddae518dce6 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -749,6 +749,11 @@ struct perf_event_context { int nr_stat; int nr_freq; int rotate_disable; + /* + * Set when nr_events != nr_active, except tolerant to events not + * necessary to be active due to scheduling constraints, such as cgroups. + */ + int rotate_necessary; refcount_t refcount; struct task_struct *task; |