[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <1337048075-6132-45-git-send-email-paul.gortmaker@windriver.com>
Date: Mon, 14 May 2012 22:12:20 -0400
From: Paul Gortmaker <paul.gortmaker@...driver.com>
To: <stable@...nel.org>, <linux-kernel@...r.kernel.org>
Subject: [34-longterm 044/179] UBIFS: fix shrinker object count reports
From: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------
commit cf610bf4199770420629d3bc273494bd27ad6c1d upstream.
Sometimes VM asks the shrinker to return amount of objects it can shrink,
and we return the ubifs_clean_zn_cnt in that case. However, it is possible
that this counter is negative for a short period of time, due to the way
UBIFS TNC code updates it. And I can observe the following warnings sometimes:
shrink_slab: ubifs_shrinker+0x0/0x2b7 [ubifs] negative objects to delete nr=-8541616642706119788
This patch makes sure UBIFS never returns negative count of objects.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
fs/ubifs/shrinker.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 02feb59..aec6689 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -283,7 +283,11 @@ int ubifs_shrinker(int nr, gfp_t gfp_mask)
long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
if (nr == 0)
- return clean_zn_cnt;
+ /*
+ * Due to the way UBIFS updates the clean znode counter it may
+ * temporarily be negative.
+ */
+ return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
if (!clean_zn_cnt) {
/*
--
1.7.9.6
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists