From: Wu Fengguang <fengguang.wu@intel.com>
To: "linux-mm@kvack.org" <linux-mm@kvack.org>
Cc: Mel Gorman <mel@csn.ul.ie>, Jan Kara <jack@suse.cz>,
Wu Fengguang <fengguang.wu@intel.com>,
Rik van Riel <riel@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Minchan Kim <minchan.kim@gmail.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 2/4] writeback: quit background/periodic work when other works are enqueued
Date: Mon, 13 Sep 2010 20:31:12 +0800 [thread overview]
Message-ID: <20100913130149.994322762@intel.com> (raw)
In-Reply-To: 20100913123110.372291929@intel.com
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From: Jan Kara <jack@suse.cz>
Background writeback and kupdate-style writeback are easily livelockable
(from a definition of their target). This is inconvenient because it can
make sync(1) stall forever waiting on its queued work to be finished.
Fix the problem by interrupting background and kupdate writeback if there
is some other work to do. We can return to them after completing all the
queued work.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
fs/fs-writeback.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- linux-next.orig/fs/fs-writeback.c 2010-09-13 13:58:47.000000000 +0800
+++ linux-next/fs/fs-writeback.c 2010-09-13 14:03:54.000000000 +0800
@@ -643,6 +643,14 @@ static long wb_writeback(struct bdi_writ
break;
/*
+ * Background writeout and kupdate-style writeback are
+ * easily livelockable. Stop them if there is other work
+ * to do so that e.g. sync can proceed.
+ */
+ if ((work->for_background || work->for_kupdate) &&
+ !list_empty(&wb->bdi->work_list))
+ break;
+ /*
* For background writeout, stop when we are below the
* background dirty threshold
*/
--
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next prev parent reply other threads:[~2010-09-13 13:08 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-13 12:31 [PATCH 0/4] [RFC] transfer vmscan pageout works to the flusher thread Wu Fengguang
2010-09-13 12:31 ` [PATCH 1/4] writeback: integrated background work Wu Fengguang
2010-09-13 22:46 ` Minchan Kim
2010-09-14 0:53 ` Wu Fengguang
2010-09-14 12:45 ` Jan Kara
2010-09-13 12:31 ` Wu Fengguang [this message]
2010-09-14 12:40 ` [PATCH 2/4] writeback: quit background/periodic work when other works are enqueued Jan Kara
2010-11-01 12:07 ` Wu Fengguang
2010-11-01 15:08 ` Jan Kara
2010-11-01 15:13 ` Jan Kara
2010-11-01 12:14 ` [PATCH 1/2] writeback: integrated background writeback work Wu Fengguang
2010-11-01 12:22 ` [PATCH 2/2] writeback: stop background/kupdate works from livelocking other works Wu Fengguang
2010-11-01 15:22 ` Christoph Hellwig
2010-11-02 1:57 ` Minchan Kim
2010-11-05 12:15 ` Johannes Weiner
2010-11-01 15:21 ` [PATCH 1/2] writeback: integrated background writeback work Christoph Hellwig
2010-11-01 20:37 ` Wu Fengguang
2010-11-01 20:39 ` [PATCH 1/2 v2] " Wu Fengguang
2010-11-02 1:55 ` Minchan Kim
2010-11-05 12:01 ` Johannes Weiner
2010-09-13 12:31 ` [PATCH 3/4] writeback: introduce bdi_start_inode_writeback() Wu Fengguang
2010-09-14 13:36 ` Jan Kara
2010-11-01 12:35 ` Wu Fengguang
2010-09-13 12:31 ` [PATCH 4/4] vmscan: transfer async file writeback to the flusher Wu Fengguang
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