Commit-ID: 835095653ebfe4b16596a30db1c4e7c414014b5e
Gitweb: http://git.kernel.org/tip/835095653ebfe4b16596a30db1c4e7c414014b5e
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Thu, 13 Aug 2015 12:40:56 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 17 Aug 2015 11:08:37 -0300
perf tools: Add a helper function to probe whether cpu-wide tracing is possible
Add a helper function to probe whether cpu-wide tracing is possible.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1439458857-30636-2-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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 3977570..436e358 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 0d228a2..0467367 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;
--
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