diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 29e5307945bf345b3fcc866d7ce9866eae1a1515..63ee0408761d2f16aa1aacd64a374e5ca5859a94 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -293,6 +293,10 @@ When processing pre-existing threads /proc/XXX/mmap, it may take a long time, because the file may be huge. A time out is needed in such cases. This option sets the time out limit. The default value is 500 ms. +--switch-events:: +Record context switch events i.e. events of type PERF_RECORD_SWITCH or +PERF_RECORD_SWITCH_CPU_WIDE. + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1] diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 1932e27c00d88de74efa8a6c5315baf853c0b65d..445a64d19625493be60b7603fa795a617a68b5b9 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1075,6 +1075,8 @@ struct option __record_options[] = { "opts", "AUX area tracing Snapshot Mode", ""), OPT_UINTEGER(0, "proc-map-timeout", &record.opts.proc_map_timeout, "per thread proc mmap processing timeout in ms"), + OPT_BOOLEAN(0, "switch-events", &record.opts.record_switch_events, + "Record context switch events"), OPT_END() }; @@ -1102,6 +1104,11 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) " system-wide mode\n"); usage_with_options(record_usage, record_options); } + if (rec->opts.record_switch_events && + !perf_can_record_switch_events()) { + ui__error("kernel does not support recording context switch events (--switch-events option)\n"); + usage_with_options(record_usage, record_options); + } if (!rec->itr) { rec->itr = auxtrace_record__init(rec->evlist, &err); diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 937b16aa0300d92fddb065858d8b36274ec24b93..cf459f89fc9bd94cfe8e1d684c78bd00402f2855 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -57,6 +57,7 @@ struct record_opts { bool running_time; bool full_auxtrace; bool auxtrace_snapshot_mode; + bool record_switch_events; unsigned int freq; unsigned int mmap_pages; unsigned int auxtrace_mmap_pages; diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 406a8216a51e1530027579d688413c4415a662b7..a8930b68456b07e1ee05317deb375e1788b29e53 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -114,6 +114,7 @@ void perf_evlist__close(struct perf_evlist *evlist); void perf_evlist__set_id_pos(struct perf_evlist *evlist); bool perf_can_sample_identifier(void); +bool perf_can_record_switch_events(void); void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts); int record_opts__config(struct record_opts *opts); diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 9e6e6f40b7871778a9de342adbe157dd33ba2d92..71f6905c7cb9f5ef85e4b19e290082f752d35756 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -738,6 +738,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts) attr->mmap2 = track && !perf_missing_features.mmap2; attr->comm = track; + if (opts->record_switch_events) + attr->context_switch = track; + if (opts->sample_transaction) perf_evsel__set_sample_bit(evsel, TRANSACTION); diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 1f7becbe5e182a4f560dd5f435148d302a5aa787..0d228a29526dded5d329e20ca6fe4f51bb94cf85 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -85,6 +85,11 @@ static void perf_probe_comm_exec(struct perf_evsel *evsel) evsel->attr.comm_exec = 1; } +static void perf_probe_context_switch(struct perf_evsel *evsel) +{ + evsel->attr.context_switch = 1; +} + bool perf_can_sample_identifier(void) { return perf_probe_api(perf_probe_sample_identifier); @@ -95,6 +100,11 @@ static bool perf_can_comm_exec(void) return perf_probe_api(perf_probe_comm_exec); } +bool perf_can_record_switch_events(void) +{ + return perf_probe_api(perf_probe_context_switch); +} + void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts) { struct perf_evsel *evsel;