[tip:perf/core] perf: Ignore non-sampling overflows

tip-bot for Peter Zijlstra
2010-11-26T15:05:26Z

Commit-ID: 963988262c3c8f4234f64a0dde59446a295e07bb
Gitweb: http://git.kernel.org/tip/963988262c3c8f4234f64a0dde59446a295e07bb
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 24 Nov 2010 18:55:29 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 26 Nov 2010 15:14:55 +0100

perf: Ignore non-sampling overflows

Some arch implementations call perf_event_overflow() by 'accident',
ignore this.

Reported-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/perf_event.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 98c5549..af1e63f 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4240,6 +4240,13 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
struct hw_perf_event *hwc = &event->hw;
int ret = 0;

+ /*
+ * Non-sampling counters might still use the PMI to fold short
+ * hardware counters, ignore those.
+ */
+ if (unlikely(!is_sampling_event(event)))
+ return 0;
+
if (!throttle) {
hwc->interrupts++;
} else {