diff options
Diffstat (limited to 'tools/perf/util/record.c')
| -rw-r--r-- | tools/perf/util/record.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 7def66168503..6d3e3df6e2a1 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -167,6 +167,64 @@ bool perf_can_aux_sample(void) return true; } +/* + * 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 (evsel == read_sampler) + return; + + /* + * 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; + attr->sample_period = 0; + attr->write_backward = 0; + + /* + * 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 = read_sampler->core.attr.sample_type | + leader->core.attr.sample_type; +} + void perf_evlist__config(struct evlist *evlist, struct record_opts *opts, struct callchain_param *callchain) { @@ -193,6 +251,10 @@ void perf_evlist__config(struct evlist *evlist, struct record_opts *opts, evsel->core.attr.comm_exec = 1; } + /* Configure leader sampling here now that the sample type is known */ + evlist__for_each_entry(evlist, evsel) + perf_evsel__config_leader_sampling(evsel, evlist); + if (opts->full_auxtrace) { /* * Need to be able to synthesize and parse selected events with |