diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/Documentation/perf-list.txt | 3 | ||||
| -rw-r--r-- | tools/perf/util/record.c | 45 |
2 files changed, 42 insertions, 6 deletions
diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index 6345db33c533..cb23667531ab 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -258,6 +258,9 @@ Normally all events in an event group sample, but with :S only the first event (the leader) samples, and it only reads the values of the other events in the group. +However, in the case AUX area events (e.g. Intel PT or CoreSight), the AUX +area event must be the leader, so then the second event samples, not the first. + OPTIONS ------- diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 32aeeb8a8d00..6d3e3df6e2a1 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -167,17 +167,46 @@ bool perf_can_aux_sample(void) return true; } -static void perf_evsel__config_leader_sampling(struct evsel *evsel) +/* + * perf_evsel__config_leader_sampling() uses special rules for leader sampling. + * However, if the leader is an AUX area event, then assume the event to sample + * is the next event. + */ +static struct evsel *perf_evsel__read_sampler(struct evsel *evsel, + struct evlist *evlist) +{ + struct evsel *leader = evsel->leader; + + if (perf_evsel__is_aux_event(leader)) { + evlist__for_each_entry(evlist, evsel) { + if (evsel->leader == leader && evsel != evsel->leader) + return evsel; + } + } + + return leader; +} + +static void perf_evsel__config_leader_sampling(struct evsel *evsel, + struct evlist *evlist) { struct perf_event_attr *attr = &evsel->core.attr; struct evsel *leader = evsel->leader; + struct evsel *read_sampler; + + if (!leader->sample_read) + return; + + read_sampler = perf_evsel__read_sampler(evsel, evlist); - if (leader == evsel || !leader->sample_read) + if (evsel == read_sampler) return; /* - * Disable sampling for all group members other - * than leader in case leader 'leads' the sampling. + * Disable sampling for all group members other than the leader in + * case the leader 'leads' the sampling, except when the leader is an + * AUX area event, in which case the 2nd event in the group is the one + * that 'leads' the sampling. */ attr->freq = 0; attr->sample_freq = 0; @@ -188,8 +217,12 @@ static void perf_evsel__config_leader_sampling(struct evsel *evsel) * We don't get a sample for slave events, we make them when delivering * the group leader sample. Set the slave event to follow the master * sample_type to ease up reporting. + * An AUX area event also has sample_type requirements, so also include + * the sample type bits from the leader's sample_type to cover that + * case. */ - attr->sample_type = leader->core.attr.sample_type; + attr->sample_type = read_sampler->core.attr.sample_type | + leader->core.attr.sample_type; } void perf_evlist__config(struct evlist *evlist, struct record_opts *opts, @@ -220,7 +253,7 @@ void perf_evlist__config(struct evlist *evlist, struct record_opts *opts, /* Configure leader sampling here now that the sample type is known */ evlist__for_each_entry(evlist, evsel) - perf_evsel__config_leader_sampling(evsel); + perf_evsel__config_leader_sampling(evsel, evlist); if (opts->full_auxtrace) { /* |