[PATCH 23/54] perf tools: Introduce API to pause ring buffer

[Wang Nan]

perf_evsel__pause() is introduced to pause a ring buffer. Since output
of a evsel is bound together, ioctl() on the first file is enough.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
 tools/perf/util/evsel.c | 6 ++++++
 tools/perf/util/evsel.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 7498d58..0b562cf 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1009,6 +1009,12 @@ int perf_evsel__disable(struct perf_evsel *evsel)
 				     0);
 }
 
+int perf_evsel__pause(struct perf_evsel *evsel, bool pause)
+{
+	return perf_evsel__run_ioctl(evsel, 1, 1, PERF_EVENT_IOC_PAUSE_OUTPUT,
+				     (void *)(pause ? 1UL : 0UL));
+}
+
 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
 	if (ncpus == 0 || nthreads == 0)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 022fcff..d5ae7ba 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -230,6 +230,7 @@ int perf_evsel__apply_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
 			     const char *filter);
 int perf_evsel__enable(struct perf_evsel *evsel);
 int perf_evsel__disable(struct perf_evsel *evsel);
+int perf_evsel__pause(struct perf_evsel *evsel, bool pause);
 
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
 			     struct cpu_map *cpus);
-- 
1.8.3.4