[PATCH] perf sort: only insert overhead && overhead_children when no overhead* field given

[changbin . du]

From: Changbin Du <changbin.du@xxxxxxxxx>

If we always insert 'overhead' and 'overhead_children' as sort keys,
this make it impossible to sort as overhead (which displayed as Self)
first.Ths will be a problem if the data is collected with call-graph
enabled. Then we never can sort the result as self-overhead on this
data. And sometimes the data is hard to collect.

This patch fix this by only insert overhead && overhead_children
when no overhead* field given.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
 tools/perf/util/sort.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 5762ae4..69eea3a 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2635,6 +2635,9 @@ static char *setup_overhead(char *keys)
 	if (sort__mode == SORT_MODE__DIFF)
 		return keys;
 
+	if (strstr(keys, "overhead"))
+		return keys;
+
 	keys = prefix_if_not_in("overhead", keys);
 
 	if (symbol_conf.cumulate_callchain)
-- 
2.7.4