From: Adrian Hunter <[email protected]> Add a helper function to probe whether cpu-wide tracing is possible.
Signed-off-by: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/evlist.h | 1 + tools/perf/util/record.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 397757063da1..436e358300b1 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -115,6 +115,7 @@ 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); +bool perf_can_record_cpu_wide(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/record.c b/tools/perf/util/record.c index 0d228a29526d..0467367dc315 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -105,6 +105,30 @@ bool perf_can_record_switch_events(void) return perf_probe_api(perf_probe_context_switch); } +bool perf_can_record_cpu_wide(void) +{ + struct perf_event_attr attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CPU_CLOCK, + .exclude_kernel = 1, + }; + struct cpu_map *cpus; + int cpu, fd; + + cpus = cpu_map__new(NULL); + if (!cpus) + return false; + cpu = cpus->map[0]; + cpu_map__put(cpus); + + fd = sys_perf_event_open(&attr, -1, cpu, -1, 0); + if (fd < 0) + return false; + close(fd); + + return true; +} + void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts) { struct perf_evsel *evsel; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
