linux-kernel - [PATCH 05/10] perf lock: Always check min AND max wait time

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Message-Id: <1273437818-8130-6-git-send-regression-fweisbec@gmail.com>
Date:	Sun,  9 May 2010 22:43:33 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Paul Mackerras <paulus@...ba.org>,
	Hitoshi Mitake <mitake@....info.waseda.ac.jp>
Subject: [PATCH 05/10] perf lock: Always check min AND max wait time

When a lock is acquired after beeing contended, we update the
wait time statistics for the given lock.
But if the min wait time is updated, we don't check the max wait
time. This is wrong because the first time we update the wait time,
we want to update both min and max wait time.

Before:
	Name   acquired  contended total wait (ns)   max wait (ns)   min wait (ns)
	key          8          1           21656           0           21656

After:
	Name   acquired  contended total wait (ns)   max wait (ns)   min wait (ns)
	key          8          1           21656           21656           21656

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Hitoshi Mitake <mitake@....info.waseda.ac.jp>
---
 tools/perf/builtin-lock.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index d7dde9c..e549f45 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -496,7 +496,7 @@ report_lock_acquired_event(struct trace_acquired_event *acquired_event,
 		ls->wait_time_total += contended_term;
 		if (contended_term < ls->wait_time_min)
 			ls->wait_time_min = contended_term;
-		else if (ls->wait_time_max < contended_term)
+		if (ls->wait_time_max < contended_term)
 			ls->wait_time_max = contended_term;
 		break;
 	case SEQ_STATE_RELEASED:
-- 
1.6.2.3

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