Re: [PATCH RFC 19/21] perf stat: Add requires_cpu flag for uncore

Namhyung Kim
2022-04-29T22:58:07Z

On Fri, Apr 22, 2022 at 9:25 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> Uncore events require a CPU i.e. it cannot be -1.
>
> The evsel system_wide flag is intended for events that should be on every
> CPU, which does not make sense for uncore events because uncore events do
> not map one-to-one with CPUs.
>
> These 2 requirements are not exactly the same, so introduce a new flag
> 'requires_cpu' the uncore case.

Yeah, I like this change! I was often confused by the two different things.

Thanks,
Namhyung

>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
> tools/lib/perf/evlist.c | 4 +++-
> tools/lib/perf/include/internal/evsel.h | 1 +
> tools/perf/builtin-stat.c | 5 +----
> tools/perf/util/evsel.c | 1 +
> tools/perf/util/parse-events.c | 2 +-
> 5 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
> index 37dfa9d936a7..9fbcca3fc836 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -42,7 +42,9 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
> if (!evsel->own_cpus || evlist->has_user_cpus) {
> perf_cpu_map__put(evsel->cpus);
> evsel->cpus = perf_cpu_map__get(evlist->user_requested_cpus);
> - } else if (!evsel->system_wide && perf_cpu_map__empty(evlist->user_requested_cpus)) {
> + } else if (!evsel->system_wide &&
> + !evsel->requires_cpu &&
> + perf_cpu_map__empty(evlist->user_requested_cpus)) {
> perf_cpu_map__put(evsel->cpus);
> evsel->cpus = perf_cpu_map__get(evlist->user_requested_cpus);
> } else if (evsel->cpus != evsel->own_cpus) {
> diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h
> index cfc9ebd7968e..77fbb8b97e5c 100644
> --- a/tools/lib/perf/include/internal/evsel.h
> +++ b/tools/lib/perf/include/internal/evsel.h
> @@ -50,6 +50,7 @@ struct perf_evsel {
> /* parse modifier helper */
> int nr_members;
> bool system_wide;
> + bool requires_cpu;
> int idx;
> };
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index a96f106dc93a..8972ae546cfe 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -364,9 +364,6 @@ static int read_counter_cpu(struct evsel *counter, struct timespec *rs, int cpu_
> if (!counter->supported)
> return -ENOENT;
>
> - if (counter->core.system_wide)
> - nthreads = 1;
> -
> for (thread = 0; thread < nthreads; thread++) {
> struct perf_counts_values *count;
>
> @@ -2224,7 +2221,7 @@ static void setup_system_wide(int forks)
> struct evsel *counter;
>
> evlist__for_each_entry(evsel_list, counter) {
> - if (!counter->core.system_wide &&
> + if (!counter->core.requires_cpu &&
> strcmp(counter->name, "duration_time")) {
> return;
> }
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 2a1729e7aee4..81bbddb6fbc0 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -382,6 +382,7 @@ struct evsel *evsel__clone(struct evsel *orig)
> evsel->core.threads = perf_thread_map__get(orig->core.threads);
> evsel->core.nr_members = orig->core.nr_members;
> evsel->core.system_wide = orig->core.system_wide;
> + evsel->core.requires_cpu = orig->core.requires_cpu;
>
> if (orig->name) {
> evsel->name = strdup(orig->name);
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index dd84fed698a3..783359017548 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -350,7 +350,7 @@ __add_event(struct list_head *list, int *idx,
> (*idx)++;
> evsel->core.cpus = cpus;
> evsel->core.own_cpus = perf_cpu_map__get(cpus);
> - evsel->core.system_wide = pmu ? pmu->is_uncore : false;
> + evsel->core.requires_cpu = pmu ? pmu->is_uncore : false;
> evsel->auto_merge_stats = auto_merge_stats;
>
> if (name)
> --
> 2.25.1
>