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authorAdrian Hunter <adrian.hunter@intel.com>2015-08-13 12:40:56 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-08-17 11:08:37 -0300
commit835095653ebfe4b16596a30db1c4e7c414014b5e (patch)
tree4afc6f2ac74109a8952745cb1c0748c3bad9de6f
parentf0ee3b467ab7a74ffce75190259eb59dbf30ecad (diff)
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@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1439458857-30636-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/util/evlist.h1
-rw-r--r--tools/perf/util/record.c24
2 files changed, 25 insertions, 0 deletions
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;