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authorWill Deacon <will.deacon@arm.com>2011-04-05 14:01:24 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-04-10 21:13:35 +0100
commit6759788b944139793bffa889761cc3d8d703fdc0 (patch)
treeac97143a319067bb8d5929d83f34df646d703189 /arch/arm/kernel/perf_event.c
parente89c0d7090c54d7b11b9b091e495a1ae345dd3ff (diff)
downloadlwn-6759788b944139793bffa889761cc3d8d703fdc0.tar.gz
lwn-6759788b944139793bffa889761cc3d8d703fdc0.zip
ARM: 6865/1: perf: ensure pass through zero is counted on overflow
Commit a737823d ("ARM: perf: ensure overflows aren't missed due to IRQ latency") changed the way that event deltas are calculated on overflow so that we don't miss events when the new count value overtakes the previous one. Unfortunately, we forget to count the event that passes through zero so we end up being off by 1. This patch adds on the correction. Reported-by: Chris Moore <moore@free.fr> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r--arch/arm/kernel/perf_event.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 69cfee0fe00f..979da3947f42 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -221,7 +221,7 @@ again:
prev_raw_count &= armpmu->max_period;
if (overflow)
- delta = armpmu->max_period - prev_raw_count + new_raw_count;
+ delta = armpmu->max_period - prev_raw_count + new_raw_count + 1;
else
delta = new_raw_count - prev_raw_count;