perf: Fix software event overflow

The below patch is for -stable only, upstream has a much larger patch
that contains the below hunk in commit a8b0ca17b80e92faab46ee7179ba9e99ccb61233

Vince found that under certain circumstances software event overflows
go wrong and deadlock. Avoid trying to delete a timer from the timer
callback.

Reported-by: Vince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Peter Zijlstra
2011-07-28 20:47:10 +02:00
committed by Greg Kroah-Hartman
parent 6e243f86d1
commit 462fee3af7

View File

@@ -5016,11 +5016,8 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
if (events && atomic_dec_and_test(&event->event_limit)) {
ret = 1;
event->pending_kill = POLL_HUP;
if (nmi) {
event->pending_disable = 1;
irq_work_queue(&event->pending);
} else
perf_event_disable(event);
event->pending_disable = 1;
irq_work_queue(&event->pending);
}
if (event->overflow_handler)