perf: Fix exit() vs event-groups

commit 96c21a460a37880abfbc8445d5b098dbab958a29 upstream.

Corey reported that the value scale times of group siblings are not
updated when the monitored task dies.

The problem appears to be that we only update the group leader's
time values, fix it by updating the whole group.

Reported-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1273588935.1810.6.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 130e0a2f0f04b8e56e47ed64e09e7eef73b9f298..78c36c5a4fe5a69798ba23911549355cc16b2cb2 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -262,6 +262,18 @@ static void update_event_times(struct perf_event *event)
        event->total_time_running = run_end - event->tstamp_running;
 }
 
+/*
+ * Update total_time_enabled and total_time_running for all events in a group.
+ */
+static void update_group_times(struct perf_event *leader)
+{
+       struct perf_event *event;
+
+       update_event_times(leader);
+       list_for_each_entry(event, &leader->sibling_list, group_entry)
+               update_event_times(event);
+}
+
 static struct list_head *
 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
 {
@@ -327,7 +339,7 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
        if (event->group_leader != event)
                event->group_leader->nr_siblings--;
 
-       update_event_times(event);
+       update_group_times(event);
 
        /*
         * If event was in error state, then keep it
@@ -508,18 +520,6 @@ retry:
        raw_spin_unlock_irq(&ctx->lock);
 }
 
-/*
- * Update total_time_enabled and total_time_running for all events in a group.
- */
-static void update_group_times(struct perf_event *leader)
-{
-       struct perf_event *event;
-
-       update_event_times(leader);
-       list_for_each_entry(event, &leader->sibling_list, group_entry)
-               update_event_times(event);
-}
-
 /*
  * Cross CPU call to disable a performance event
  */