From 039fc91e064b81c2820ff16c304be5aba35fd126 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri, 13 Mar 2009 16:43:47 +0100
Subject: [PATCH] perf_counter: fix hrtimer sampling

Impact: fix deadlock with perfstat

Fix for the perfstat fubar..

We cannot unconditionally call hrtimer_cancel() without ever having done
hrtimer_init() on the thing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Orig-LKML-Reference: <1236959027.22447.149.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/perf_counter.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 8d6ecfa64c0e5..d6cc22271ef45 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1571,9 +1571,9 @@ static int cpu_clock_perf_counter_enable(struct perf_counter *counter)
 	int cpu = raw_smp_processor_id();
 
 	atomic64_set(&hwc->prev_count, cpu_clock(cpu));
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hwc->hrtimer.function = perf_swcounter_hrtimer;
 	if (hwc->irq_period) {
-		hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-		hwc->hrtimer.function = perf_swcounter_hrtimer;
 		__hrtimer_start_range_ns(&hwc->hrtimer,
 				ns_to_ktime(hwc->irq_period), 0,
 				HRTIMER_MODE_REL, 0);
@@ -1635,9 +1635,9 @@ static int task_clock_perf_counter_enable(struct perf_counter *counter)
 	struct hw_perf_counter *hwc = &counter->hw;
 
 	atomic64_set(&hwc->prev_count, task_clock_perf_counter_val(counter, 0));
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hwc->hrtimer.function = perf_swcounter_hrtimer;
 	if (hwc->irq_period) {
-		hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-		hwc->hrtimer.function = perf_swcounter_hrtimer;
 		__hrtimer_start_range_ns(&hwc->hrtimer,
 				ns_to_ktime(hwc->irq_period), 0,
 				HRTIMER_MODE_REL, 0);
-- 
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