[RFC PATCH v1 1/3] perf evsel: Don't open tool events

[Ian Rogers <irogers@google.com>]

Tool events are set up as software dummy events. Don't open them to
save some work and a file descriptor. The evsel's fds are initialized
to -1, so it suffices to just early return.
---
 tools/perf/util/evsel.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3536404e9447..2743d40665ff 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2005,6 +2005,11 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 	int pid = -1, err, old_errno;
 	enum rlimit_action set_rlimit = NO_CHANGE;
 
+	if (evsel__is_tool(evsel)) {
+		/* Tool events are set up as dummy but don't need opening. */
+		return 0;
+	}
+
 	err = __evsel__prepare_open(evsel, cpus, threads);
 	if (err)
 		return err;
-- 
2.44.0.769.g3c40516874-goog