Commit 704e2f5b authored by Andi Kleen's avatar Andi Kleen Committed by Arnaldo Carvalho de Melo
Browse files

perf stat: Use affinity for enabling/disabling events 



Restructure event enabling/disabling to use affinity, which
minimizes the number of IPIs needed.

Before on a large test case with 94 CPUs:

  % time     seconds  usecs/call     calls    errors syscall
  ------ ----------- ----------- --------- --------- ----------------
   54.65    1.899986          22     84812       660 ioctl

after:

   39.21    0.930451          10     84796       644 ioctl

Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191121001522.180827-13-andi@firstfloor.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 363fb121

tools/perf/util/evlist.c

+37 −3
Original line number Diff line number Diff line
@@ -378,11 +378,28 @@ bool evsel__cpu_iter_skip(struct evsel *ev, int cpu) 
void evlist__disable(struct evlist *evlist)

{

	struct evsel *pos;

	struct affinity affinity;

	int cpu, i;



	if (affinity__setup(&affinity) < 0)

		return;



	evlist__for_each_cpu(evlist, i, cpu) {

		affinity__set(&affinity, cpu);



		evlist__for_each_entry(evlist, pos) {

			if (evsel__cpu_iter_skip(pos, cpu))

				continue;

			if (pos->disabled || !perf_evsel__is_group_leader(pos) || !pos->core.fd)

				continue;

		evsel__disable(pos);

			evsel__disable_cpu(pos, pos->cpu_iter - 1);

		}

	}

	affinity__cleanup(&affinity);

	evlist__for_each_entry(evlist, pos) {

		if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)

			continue;

		pos->disabled = true;

	}



	evlist->enabled = false;
@@ -391,11 +408,28 @@ void evlist__disable(struct evlist *evlist) 
void evlist__enable(struct evlist *evlist)

{

	struct evsel *pos;

	struct affinity affinity;

	int cpu, i;



	if (affinity__setup(&affinity) < 0)

		return;



	evlist__for_each_cpu(evlist, i, cpu) {

		affinity__set(&affinity, cpu);



		evlist__for_each_entry(evlist, pos) {

			if (evsel__cpu_iter_skip(pos, cpu))

				continue;

			if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)

				continue;

			evsel__enable_cpu(pos, pos->cpu_iter - 1);

		}

	}

	affinity__cleanup(&affinity);

	evlist__for_each_entry(evlist, pos) {

		if (!perf_evsel__is_group_leader(pos) || !pos->core.fd)

			continue;

		evsel__enable(pos);

		pos->disabled = false;

	}



	evlist->enabled = true;

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