Re: [PATCH] perf evlist: Ensure grouped events with same cpu map

Jiri Olsa
2020-05-22T09:53:28Z

On Thu, May 21, 2020 at 02:22:40PM +0800, Jin Yao wrote:

SNIP

> ---
> tools/perf/builtin-stat.c | 3 +++
> tools/perf/util/evlist.c | 32 ++++++++++++++++++++++++++++++++
> tools/perf/util/evlist.h | 5 +++++
> 3 files changed, 40 insertions(+)
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 377e575f9645..0e4fc6b3323c 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -584,6 +584,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
> if (affinity__setup(&affinity) < 0)
> return -1;
>
> + if (!evlist__cpus_matched(evsel_list))
> + evlist__force_disable_group(evsel_list);
> +
> evlist__for_each_cpu (evsel_list, i, cpu) {
> affinity__set(&affinity, cpu);
>
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 2a9de6491700..fc6e410ca63b 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -1704,3 +1704,35 @@ struct evsel *perf_evlist__reset_weak_group(struct evlist *evsel_list,
> }
> return leader;
> }
> +
> +bool evlist__cpus_matched(struct evlist *evlist)
> +{
> + struct evsel *prev = evlist__first(evlist), *evsel = prev;
> +
> + if (prev->core.nr_members <= 1)
> + return true;

hum, this assumes there's only one group in evlist?

how about case like A,{B,C},D,{E,F}

also please add automated tests for this

> +
> + evlist__for_each_entry_continue(evlist, evsel) {
> + if (evsel->core.cpus->nr != prev->core.cpus->nr)
> + return false;
> +
> + for (int i = 0; i < evsel->core.cpus->nr; i++) {
> + if (evsel->core.cpus->map[i] != prev->core.cpus->map[i])
> + return false;
> + }
> +
> + prev = evsel;
> + }
> +
> + return true;
> +}
> +
> +void evlist__force_disable_group(struct evlist *evlist)
> +{
> + struct evsel *evsel;

we need to put some warning for user in here

thanks,
jirka

> +
> + evlist__for_each_entry(evlist, evsel) {
> + evsel->leader = evsel;
> + evsel->core.nr_members = 0;
> + }
> +}
> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
> index b6f325dfb4d2..ea7a53166cbd 100644
> --- a/tools/perf/util/evlist.h
> +++ b/tools/perf/util/evlist.h
> @@ -355,4 +355,9 @@ void perf_evlist__force_leader(struct evlist *evlist);
> struct evsel *perf_evlist__reset_weak_group(struct evlist *evlist,
> struct evsel *evsel,
> bool close);
> +
> +bool evlist__cpus_matched(struct evlist *evlist);
> +
> +void evlist__force_disable_group(struct evlist *evlist);
> +
> #endif /* __PERF_EVLIST_H */
> --
> 2.17.1
>