From 72523d8082df3d89bffe30cbc1356dbb45ab51ae Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Thu, 18 Oct 2012 10:36:11 +1100
Subject: [PATCH] Revert "powerpc/perf: Use pmc_overflow() to detect rolled
back events"
This reverts commit 813312110bede27bffd082c25cd31730bd567beb.
This revert was requested by the author of the patch as it seems
to cause system hangs with some low frequency events
---
arch/powerpc/perf/core-book3s.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 0db88f501f91..aa2465e21f1a 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1463,7 +1463,7 @@ static void perf_event_interrupt(struct pt_regs *regs)
if (!event->hw.idx || is_limited_pmc(event->hw.idx))
continue;
val = read_pmc(event->hw.idx);
- if (pmc_overflow(val)) {
+ if ((int)val < 0) {
/* event has overflowed */
found = 1;
record_and_restart(event, val, regs);
--
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