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perf sched timehist: Split is_idle_sample()

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The is_idle_sample() function actually does more than determining
whether sample come from idle task.  Split the callchain part into
save_task_callchain() to make it clearer.

Also checking prev_pid from trace data looks preferred than just
checking sample->pid since it's possible, although rare, to have invalid
0 pid/tid on scheduling an exiting task.

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/20161208144755.16673-2-namhyung@kernel.org
[ Remove some needless () in some return statements ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2016-12-08 23:47:50 +09:00 committed by Arnaldo Carvalho de Melo
parent aeafd623f8
commit 96039c7c52
1 changed files with 20 additions and 19 deletions
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39
tools/perf/builtin-sched.c
View file

@ -1939,39 +1939,40 @@ static void timehist_update_runtime_stats(struct thread_runtime *r,
r->total_run_time += r->dt_run;
}
static bool is_idle_sample(struct perf_sched *sched,
struct perf_sample *sample,
struct perf_evsel *evsel,
struct machine *machine)
static bool is_idle_sample(struct perf_sample *sample,
struct perf_evsel *evsel)
{
struct thread *thread;
struct callchain_cursor *cursor = &callchain_cursor;
/* pid 0 == swapper == idle task */
if (sample->pid == 0)
return true;
if (strcmp(perf_evsel__name(evsel), "sched:sched_switch") == 0)
return perf_evsel__intval(evsel, sample, "prev_pid") == 0;
if (strcmp(perf_evsel__name(evsel), "sched:sched_switch") == 0) {
if (perf_evsel__intval(evsel, sample, "prev_pid") == 0)
return true;
}
return sample->pid == 0;
}
static void save_task_callchain(struct perf_sched *sched,
struct perf_sample *sample,
struct perf_evsel *evsel,
struct machine *machine)
{
struct callchain_cursor *cursor = &callchain_cursor;
struct thread *thread;
/* want main thread for process - has maps */
thread = machine__findnew_thread(machine, sample->pid, sample->pid);
if (thread == NULL) {
pr_debug("Failed to get thread for pid %d.\n", sample->pid);
return false;
return;
}
if (!symbol_conf.use_callchain || sample->callchain == NULL)
return false;
return;
if (thread__resolve_callchain(thread, cursor, evsel, sample,
NULL, NULL, sched->max_stack + 2) != 0) {
if (verbose)
error("Failed to resolve callchain. Skipping\n");
return false;
return;
}
callchain_cursor_commit(cursor);
@ -1994,8 +1995,6 @@ static bool is_idle_sample(struct perf_sched *sched,
callchain_cursor_advance(cursor);
}
return false;
}
/*
@ -2111,7 +2110,7 @@ static struct thread *timehist_get_thread(struct perf_sched *sched,
{
struct thread *thread;
if (is_idle_sample(sched, sample, evsel, machine)) {
if (is_idle_sample(sample, evsel)) {
thread = get_idle_thread(sample->cpu);
if (thread == NULL)
pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu);
@ -2124,6 +2123,8 @@ static struct thread *timehist_get_thread(struct perf_sched *sched,
pr_debug("Failed to get thread for tid %d. skipping sample.\n",
sample->tid);
}
save_task_callchain(sched, sample, evsel, machine);
}
return thread;