Commit ea0ddc27 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
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perf lock: Carefully combine lock stats for discarded entries 



Stats from discarded entries should be omitted.

But a lock class may have both good and bad entries.

If the first entry was bad, we can zero-fill the stats and only add good
stats if any.

The entry can remove the discard state if it finds a good entry later.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220127000050.3011493-7-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0d435bf8

tools/perf/builtin-lock.c

+16 −0
Original line number Diff line number Diff line
@@ -295,6 +295,9 @@ static void combine_lock_stats(struct lock_stat *st) 
			ret = !!st->name - !!p->name;



		if (ret == 0) {

			if (st->discard)

				goto out;



			p->nr_acquired += st->nr_acquired;

			p->nr_contended += st->nr_contended;

			p->wait_time_total += st->wait_time_total;
@@ -307,6 +310,10 @@ static void combine_lock_stats(struct lock_stat *st) 
			if (p->wait_time_max < st->wait_time_max)

				p->wait_time_max = st->wait_time_max;



			/* now it got a new !discard record */

			p->discard = 0;



out:

			st->combined = 1;

			return;

		}
@@ -319,6 +326,15 @@ static void combine_lock_stats(struct lock_stat *st) 


	rb_link_node(&st->rb, parent, rb);

	rb_insert_color(&st->rb, &sorted);



	if (st->discard) {

		st->nr_acquired = 0;

		st->nr_contended = 0;

		st->wait_time_total = 0;

		st->avg_wait_time = 0;

		st->wait_time_min = ULLONG_MAX;

		st->wait_time_max = 0;

	}

}



static void insert_to_result(struct lock_stat *st,