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authorAlexey Budankov <alexey.budankov@linux.intel.com>2018-04-09 10:25:32 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2018-04-17 09:47:39 -0300
commit101592b4904ecf6b8ed2a4784d41d180319d95a1 (patch)
treef8e1c8fefe00c62600474711085692adfad8971d /kernel/events
parente2f73a1828e9ffd2765ce1726b9a9c6e022e3cd6 (diff)
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')
-rw-r--r--kernel/events/core.c4
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);