Messages in this thread | | | Date | Thu, 12 May 2022 07:33:05 +0300 | Subject | Re: [PATCH V3 13/23] perf evlist: Add evlist__add_dummy_on_all_cpus() | From | Adrian Hunter <> |
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On 12/05/22 01:50, Namhyung Kim wrote: > On Wed, May 11, 2022 at 12:02 AM Adrian Hunter <adrian.hunter@intel.com> wrote: >> >> Add evlist__add_dummy_on_all_cpus() to enable creating a system-wide dummy >> event that sets up the system-wide maps before map propagation. >> >> For convenience, add evlist__add_aux_dummy() so that the logic can be used >> whether or not the event needs to be system-wide. >> >> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> >> --- >> >> Changes in V3: Amended comment about all CPUs. >> >> tools/perf/util/evlist.c | 45 ++++++++++++++++++++++++++++++++++++++++ >> tools/perf/util/evlist.h | 5 +++++ >> 2 files changed, 50 insertions(+) >> >> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c >> index 78c47cbafbc2..2b2900434bba 100644 >> --- a/tools/perf/util/evlist.c >> +++ b/tools/perf/util/evlist.c >> @@ -264,6 +264,51 @@ int evlist__add_dummy(struct evlist *evlist) >> return 0; >> } >> >> +static void evlist__add_on_all_cpus(struct evlist *evlist, struct evsel *evsel) >> +{ >> + evsel->core.system_wide = true; >> + >> + /* >> + * All CPUs. >> + * >> + * Note perf_event_open() does not accept CPUs that are not online, so >> + * in fact this CPU list will include only all online CPUs. >> + */ >> + perf_cpu_map__put(evsel->core.own_cpus); >> + evsel->core.own_cpus = perf_cpu_map__new(NULL); >> + perf_cpu_map__put(evsel->core.cpus); >> + evsel->core.cpus = perf_cpu_map__get(evsel->core.own_cpus); > > Maybe I'm missing something.. Wouldn't it be overwritten > by the user requested cpus during map propagation in > evlist__add()?
Yes. That gets changed in patch 22 "perf tools: Allow system-wide events to keep their own CPUs"
> > Thanks, > Namhyung > > >> + >> + /* No threads */ >> + perf_thread_map__put(evsel->core.threads); >> + evsel->core.threads = perf_thread_map__new_dummy(); >> + >> + evlist__add(evlist, evsel); >> +} >> + >> +struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide) >> +{ >> + struct evsel *evsel = evlist__dummy_event(evlist); >> + >> + if (!evsel) >> + return NULL; >> + >> + evsel->core.attr.exclude_kernel = 1; >> + evsel->core.attr.exclude_guest = 1; >> + evsel->core.attr.exclude_hv = 1; >> + evsel->core.attr.freq = 0; >> + evsel->core.attr.sample_period = 1; >> + evsel->no_aux_samples = true; >> + evsel->name = strdup("dummy:u"); >> + >> + if (system_wide) >> + evlist__add_on_all_cpus(evlist, evsel); >> + else >> + evlist__add(evlist, evsel); >> + >> + return evsel; >> +} >> + >> static int evlist__add_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs) >> { >> struct evsel *evsel, *n; >> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h >> index 4062f5aebfc1..1bde9ccf4e7d 100644 >> --- a/tools/perf/util/evlist.h >> +++ b/tools/perf/util/evlist.h >> @@ -114,6 +114,11 @@ int arch_evlist__add_default_attrs(struct evlist *evlist); >> struct evsel *arch_evlist__leader(struct list_head *list); >> >> int evlist__add_dummy(struct evlist *evlist); >> +struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide); >> +static inline struct evsel *evlist__add_dummy_on_all_cpus(struct evlist *evlist) >> +{ >> + return evlist__add_aux_dummy(evlist, true); >> +} >> >> int evlist__add_sb_event(struct evlist *evlist, struct perf_event_attr *attr, >> evsel__sb_cb_t cb, void *data); >> -- >> 2.25.1 >>
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