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From: Christoph Lameter <cl@linux.com>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org
Subject: vmstat: Update comment in stat_threshold
Date: Wed, 23 Mar 2011 15:46:20 -0500 (CDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1103231542200.14654@router.home> (raw)

This has been in my tree for awhile. I thought it would be merged
at some point into another patch but that did not happen.

It was first posted in a discussion of the vmstat changes for per cpu
atomics: http://www.gossamer-threads.com/lists/linux/kernel/1317000#1317000

Signed-off-by: Christoph Lameter <cl@linux.com>


---
 mm/vmstat.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Index: linux-2.6/mm/vmstat.c
===================================================================
--- linux-2.6.orig/mm/vmstat.c	2011-03-15 11:16:48.000000000 -0500
+++ linux-2.6/mm/vmstat.c	2011-03-17 09:25:26.000000000 -0500
@@ -321,9 +321,12 @@ static inline void mod_state(struct zone
 		/*
 		 * The fetching of the stat_threshold is racy. We may apply
 		 * a counter threshold to the wrong the cpu if we get
-		 * rescheduled while executing here. However, the following
-		 * will apply the threshold again and therefore bring the
-		 * counter under the threshold.
+		 * rescheduled while executing here. However, the next
+		 * counter update will apply the threshold again and
+		 * therefore bring the counter under the threshold again.
+		 *
+		 * Most of the time the thresholds are the same anyways
+		 * for all cpus in a zone.
 		 */
 		t = this_cpu_read(pcp->stat_threshold);

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                 reply	other threads:[~2011-03-23 20:46 UTC|newest]

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