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| author | Namhyung Kim <namhyung@kernel.org> | 2016-12-08 23:47:52 +0900 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-12-15 16:25:44 -0300 |
| commit | 699b5b920db04a6ff5c03a519e4c182aeb350952 (patch) | |
| tree | aab4112c7710f7cb813ecaad9a1d27b441ff1b39 /tools | |
| parent | 3bc2fa9cb829ccf6527e7117d9af769d93ee6d39 (diff) | |
| download | lwn-699b5b920db04a6ff5c03a519e4c182aeb350952.tar.gz lwn-699b5b920db04a6ff5c03a519e4c182aeb350952.zip | |
perf sched timehist: Save callchain when entering idle
In order to investigate the idleness reason, it is necessary to keep the
callchains when entering idle. This can be identified by the
sched:sched_switch event having the next_pid field as 0.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20161208144755.16673-4-namhyung@kernel.org
Link: http://lkml.kernel.org/r/20161213080632.19099-1-namhyung@kernel.org
[ Merged fix from Namhyung, see second Link: tag ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/builtin-sched.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index e108b0f6a246..dc83b803ca54 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -200,6 +200,7 @@ struct perf_sched { /* options for timehist command */ bool summary; bool summary_only; + bool idle_hist; bool show_callchain; unsigned int max_stack; bool show_cpu_visual; @@ -2101,6 +2102,15 @@ static struct thread *get_idle_thread(int cpu) return idle_threads[cpu]; } +static void save_idle_callchain(struct idle_thread_runtime *itr, + struct perf_sample *sample) +{ + if (!symbol_conf.use_callchain || sample->callchain == NULL) + return; + + callchain_cursor__copy(&itr->cursor, &callchain_cursor); +} + /* * handle runtime stats saved per thread */ @@ -2154,6 +2164,26 @@ static struct thread *timehist_get_thread(struct perf_sched *sched, } save_task_callchain(sched, sample, evsel, machine); + if (sched->idle_hist) { + struct thread *idle; + struct idle_thread_runtime *itr; + + idle = get_idle_thread(sample->cpu); + if (idle == NULL) { + pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu); + return NULL; + } + + itr = thread__priv(idle); + if (itr == NULL) + return NULL; + + itr->last_thread = thread; + + /* copy task callchain when entering to idle */ + if (perf_evsel__intval(evsel, sample, "next_pid") == 0) + save_idle_callchain(itr, sample); + } } return thread; |