[tip:perf/urgent] perf sched timehist: Show total scheduling time

From: tip-bot for Namhyung Kim
Date: Thu Jan 05 2017 - 02:50:02 EST


Commit-ID: 9396c9cb0d9534ca67bda8a34b2413a2ca1c67e9
Gitweb: http://git.kernel.org/tip/9396c9cb0d9534ca67bda8a34b2413a2ca1c67e9
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
AuthorDate: Thu, 22 Dec 2016 15:03:50 +0900
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 27 Dec 2016 21:47:57 -0300

perf sched timehist: Show total scheduling time

Show length of analyzed sample time and rate of idle task running.
This also takes care of time range given by --time option.

$ perf sched timehist -sI | tail
Samples do not have callchains.
Idle stats:
CPU 0 idle for 930.316 msec ( 92.93%)
CPU 1 idle for 963.614 msec ( 96.25%)
CPU 2 idle for 885.482 msec ( 88.45%)
CPU 3 idle for 938.635 msec ( 93.76%)

Total number of unique tasks: 118
Total number of context switches: 2337
Total run time (msec): 3718.048
Total scheduling time (msec): 1001.131 (x 4)

Suggested-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20161222060350.17655-3-namhyung@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-sched.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index d53e706..5b134b0 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -209,6 +209,7 @@ struct perf_sched {
u64 skipped_samples;
const char *time_str;
struct perf_time_interval ptime;
+ struct perf_time_interval hist_time;
};

/* per thread run time data */
@@ -2460,6 +2461,11 @@ static int timehist_sched_change_event(struct perf_tool *tool,
timehist_print_sample(sched, sample, &al, thread, t);

out:
+ if (sched->hist_time.start == 0 && t >= ptime->start)
+ sched->hist_time.start = t;
+ if (ptime->end == 0 || t <= ptime->end)
+ sched->hist_time.end = t;
+
if (tr) {
/* time of this sched_switch event becomes last time task seen */
tr->last_time = sample->time;
@@ -2624,6 +2630,7 @@ static void timehist_print_summary(struct perf_sched *sched,
struct thread *t;
struct thread_runtime *r;
int i;
+ u64 hist_time = sched->hist_time.end - sched->hist_time.start;

memset(&totals, 0, sizeof(totals));

@@ -2665,7 +2672,7 @@ static void timehist_print_summary(struct perf_sched *sched,
totals.sched_count += r->run_stats.n;
printf(" CPU %2d idle for ", i);
print_sched_time(r->total_run_time, 6);
- printf(" msec\n");
+ printf(" msec (%6.2f%%)\n", 100.0 * r->total_run_time / hist_time);
} else
printf(" CPU %2d idle entire time window\n", i);
}
@@ -2701,12 +2708,16 @@ static void timehist_print_summary(struct perf_sched *sched,

printf("\n"
" Total number of unique tasks: %" PRIu64 "\n"
- "Total number of context switches: %" PRIu64 "\n"
- " Total run time (msec): ",
+ "Total number of context switches: %" PRIu64 "\n",
totals.task_count, totals.sched_count);

+ printf(" Total run time (msec): ");
print_sched_time(totals.total_run_time, 2);
printf("\n");
+
+ printf(" Total scheduling time (msec): ");
+ print_sched_time(hist_time, 2);
+ printf(" (x %d)\n", sched->max_cpu);
}

typedef int (*sched_handler)(struct perf_tool *tool,