From: Soeren Sandmann <sandmann@daimi.au.dk>
Date: Thu, 22 Oct 2009 16:34:08 +0000 (+0200)
Subject: perf events: Don't generate events for the idle task when exclude_idle is set
X-Git-Tag: v2.6.32-rc6~16^2~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=54f4407608c59712a8f5ec1e10dfac40bef5a2e7;p=karo-tx-linux.git

perf events: Don't generate events for the idle task when exclude_idle is set

Getting samples for the idle task is often not interesting, so
don't generate them when exclude_idle is set for the event in
question.

Signed-off-by: Søren Sandmann Pedersen <sandmann@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <ye8pr8fmlq7.fsf@camel16.daimi.au.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 33ff019f9aa6..7f29643c8985 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3959,8 +3959,9 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
 		regs = task_pt_regs(current);
 
 	if (regs) {
-		if (perf_event_overflow(event, 0, &data, regs))
-			ret = HRTIMER_NORESTART;
+		if (!(event->attr.exclude_idle && current->pid == 0))
+			if (perf_event_overflow(event, 0, &data, regs))
+				ret = HRTIMER_NORESTART;
 	}
 
 	period = max_t(u64, 10000, event->hw.sample_period);