[tip:perf/core] perf evsel: Check if callchain is enabled before setting it up

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  1688c2fdf6e72633c7f463da3878b58eef01ba56
Gitweb:     https://git.kernel.org/tip/1688c2fdf6e72633c7f463da3878b58eef01ba56
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Fri, 12 Jan 2018 16:21:04 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 12 Jan 2018 16:57:16 -0300

perf evsel: Check if callchain is enabled before setting it up

The construct:

	if (callchain_param)
		perf_evsel__config_callchain(evsel, opts, &callchain_param);

happens in several places, so make perf_evsel__config_callchain() work
just like free(NULL), do nothing if param->enabled is not set.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Hendrick Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Thomas Richter <tmricht@xxxxxxxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-ykk0qzxnxwx3o611ctjnmxav@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/evsel.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 4eea3b4..efa2e62 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -651,9 +651,9 @@ int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
 	return ret;
 }
 
-void perf_evsel__config_callchain(struct perf_evsel *evsel,
-				  struct record_opts *opts,
-				  struct callchain_param *param)
+static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
+					   struct record_opts *opts,
+					   struct callchain_param *param)
 {
 	bool function = perf_evsel__is_function_event(evsel);
 	struct perf_event_attr *attr = &evsel->attr;
@@ -699,6 +699,14 @@ void perf_evsel__config_callchain(struct perf_evsel *evsel,
 	}
 }
 
+void perf_evsel__config_callchain(struct perf_evsel *evsel,
+				  struct record_opts *opts,
+				  struct callchain_param *param)
+{
+	if (param->enabled)
+		return __perf_evsel__config_callchain(evsel, opts, param);
+}
+
 static void
 perf_evsel__reset_callgraph(struct perf_evsel *evsel,
 			    struct callchain_param *param)