perf timechart: Conditionally update start_time on fork

We don't need to overwrite current task start_time on fork, so update it
only if it's zero.

Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/1404835423-23098-4-git-send-email-stfomichev@yandex-team.ru
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 4079062d25b0..37bf1eb0755f 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -242,7 +242,7 @@ static void pid_fork(struct timechart *tchart, int pid, int ppid, u64 timestamp)
                 pid_set_comm(tchart, pid, pp->current->comm);
 
         p->start_time = timestamp;
-        if (p->current) {
+        if (p->current && !p->current->start_time) {
                 p->current->start_time = timestamp;
                 p->current->state_since = timestamp;
         }