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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
parente89c0d7090c54d7b11b9b091e495a1ae345dd3ff (diff)
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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>
-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;
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