leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

perf sched timehist: Save callchain when entering idle

Browse Source 
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>
This commit is contained in:
Namhyung Kim 2016-12-08 23:47:52 +09:00 committed by Arnaldo Carvalho de Melo
parent 3bc2fa9cb8
commit 699b5b920d
1 changed files with 30 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
tools/perf/builtin-sched.c
View File

@ -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;