libperf: Add perf_evsel__cpus()/threads() functions

Add the following functions:

  perf_evsel__cpus()
  perf_evsel__threads()

to access the evsel's cpus and threads objects.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-68-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/evsel.c

@@ -215,3 +215,13 @@ int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
 				     PERF_EVENT_IOC_SET_FILTER,
 				     (void *)filter);
 }
+
+struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
+{
+	return evsel->cpus;
+}
+
+struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel)
+{
+	return evsel->threads;
+}

tools/perf/lib/include/perf/evsel.h

@@ -32,5 +32,7 @@ LIBPERF_API int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
 				 struct perf_counts_values *count);
 LIBPERF_API int perf_evsel__enable(struct perf_evsel *evsel);
 LIBPERF_API int perf_evsel__disable(struct perf_evsel *evsel);
+LIBPERF_API struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
+LIBPERF_API struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
 
 #endif /* __LIBPERF_EVSEL_H */

tools/perf/lib/libperf.map

@@ -21,6 +21,8 @@ LIBPERF_0.0.1 {
 		perf_evsel__open;
 		perf_evsel__close;
 		perf_evsel__read;
+		perf_evsel__cpus;
+		perf_evsel__threads;
 		perf_evlist__new;
 		perf_evlist__delete;
 		perf_evlist__init;

tools/perf/util/evsel.h

@@ -193,7 +193,7 @@ struct record_opts;
 
 static inline struct perf_cpu_map *evsel__cpus(struct evsel *evsel)
 {
-	return evsel->core.cpus;
+	return perf_evsel__cpus(&evsel->core);
 }
 
 static inline int perf_evsel__nr_cpus(struct evsel *evsel)