perf_events: Fix broken event grouping
Events were not grouped anymore. The reason was that in
perf_event_open(), the field event->group_leader was
initialized before the function looked up the group_fd
to find the event leader. This patch fixes this by
reordering the code correctly.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <20100917093009.360420946@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 86f394e..ce95617 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5550,17 +5550,11 @@
if (event_fd < 0)
return event_fd;
- event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
- if (IS_ERR(event)) {
- err = PTR_ERR(event);
- goto err_fd;
- }
-
if (group_fd != -1) {
group_leader = perf_fget_light(group_fd, &fput_needed);
if (IS_ERR(group_leader)) {
err = PTR_ERR(group_leader);
- goto err_alloc;
+ goto err_fd;
}
group_file = group_leader->filp;
if (flags & PERF_FLAG_FD_OUTPUT)
@@ -5569,6 +5563,12 @@
group_leader = NULL;
}
+ event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
+ if (IS_ERR(event)) {
+ err = PTR_ERR(event);
+ goto err_fd;
+ }
+
/*
* Special case software events and allow them to be part of
* any hardware group.
@@ -5653,7 +5653,6 @@
put_ctx(ctx);
err_group_fd:
fput_light(group_file, fput_needed);
-err_alloc:
free_event(event);
err_fd:
put_unused_fd(event_fd);