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| author | Alexey Budankov <alexey.budankov@linux.intel.com> | 2018-04-09 10:25:32 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-04-17 09:47:39 -0300 |
| commit | 101592b4904ecf6b8ed2a4784d41d180319d95a1 (patch) | |
| tree | f8e1c8fefe00c62600474711085692adfad8971d /kernel/events/core.c | |
| parent | e2f73a1828e9ffd2765ce1726b9a9c6e022e3cd6 (diff) | |
| download | linux-101592b4904ecf6b8ed2a4784d41d180319d95a1.tar.bz2 | |
perf/core: Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE]
Store preempting context switch out event into Perf trace as a part of
PERF_RECORD_SWITCH[_CPU_WIDE] record.
Percentage of preempting and non-preempting context switches help
understanding the nature of workloads (CPU or IO bound) that are running
on a machine;
The event is treated as preemption one when task->state value of the
thread being switched out is TASK_RUNNING. Event type encoding is
implemented using PERF_RECORD_MISC_SWITCH_OUT_PREEMPT bit;
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/9ff84e83-a0ca-dd82-a6d0-cb951689be74@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 2d5fe26551f8..1bae80aaabfb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7587,6 +7587,10 @@ static void perf_event_switch(struct task_struct *task, }, }; + if (!sched_in && task->state == TASK_RUNNING) + switch_event.event_id.header.misc |= + PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; + perf_iterate_sb(perf_event_switch_output, &switch_event, NULL); |