From: Andrew Morton <akpm@linux-foundation.org>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>, Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@infradead.org>,
<linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 01/15] writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage
Date: Tue, 7 Jun 2011 16:02:34 -0700 [thread overview]
Message-ID: <20110607160234.53de9f93.akpm@linux-foundation.org> (raw)
In-Reply-To: <20110607213853.513366237@intel.com>
On Wed, 08 Jun 2011 05:32:37 +0800
Wu Fengguang <fengguang.wu@intel.com> wrote:
> sync(2) is performed in two stages: the WB_SYNC_NONE sync and the
> WB_SYNC_ALL sync. Identify the first stage with .tagged_writepages and
> do livelock prevention for it, too.
>
> Note that writeback_inodes_sb() is called by not only sync(), they are
> treated the same because the other callers also need livelock prevention.
>
> Impact: It changes the order in which pages/inodes are synced to disk.
> Now in the WB_SYNC_NONE stage, it won't proceed to write the next inode
> until finished with the current inode.
What problem is this patch actually fixing? It sounds like there's
some livelock scenario in the WB_SYNC_NONE phase. otoh the final
paragraph implies that the WB_SYNC_NONE phase is failing to write some
pages under some situations.
Suggest that the changelog be fleshed out to cover all of this.
next prev parent reply other threads:[~2011-06-07 23:02 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-07 21:32 [PATCH 00/15] writeback fixes and cleanups for 3.0 (v5) Wu Fengguang
2011-06-07 21:32 ` [PATCH 01/15] writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage Wu Fengguang
2011-06-07 23:02 ` Andrew Morton [this message]
2011-06-07 23:24 ` Wu Fengguang
2011-06-07 21:32 ` [PATCH 02/15] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang
2011-06-07 23:02 ` Andrew Morton
2011-06-07 23:51 ` Wu Fengguang
2011-06-07 21:32 ` [PATCH 03/15] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-06-07 23:03 ` Andrew Morton
2011-06-08 0:10 ` Wu Fengguang
2011-06-07 21:32 ` [PATCH 04/15] writeback: try more writeback as long as something was written Wu Fengguang
2011-06-07 21:32 ` [PATCH 05/15] writeback: the kupdate expire timestamp should be a moving target Wu Fengguang
2011-06-07 21:32 ` [PATCH 06/15] writeback: refill b_io iff empty Wu Fengguang
2011-06-07 21:32 ` [PATCH 07/15] writeback: split inode_wb_list_lock into bdi_writeback.list_lock Wu Fengguang
2011-06-07 23:03 ` Andrew Morton
2011-06-08 0:20 ` Wu Fengguang
2011-06-08 0:35 ` Andrew Morton
2011-06-08 1:36 ` Wu Fengguang
2011-06-07 21:32 ` [PATCH 08/15] writeback: elevate queue_io() into wb_writeback() Wu Fengguang
2011-06-07 21:32 ` [PATCH 09/15] writeback: avoid extra sync work at enqueue time Wu Fengguang
2011-06-07 21:32 ` [PATCH 10/15] writeback: add bdi_dirty_limit() kernel-doc Wu Fengguang
2011-06-07 21:32 ` [PATCH 11/15] writeback: skip balance_dirty_pages() for in-memory fs Wu Fengguang
2011-06-11 13:07 ` Wu Fengguang
2011-06-13 13:42 ` Jan Kara
2011-06-07 21:32 ` [PATCH 12/15] writeback: remove writeback_control.more_io Wu Fengguang
2011-07-11 21:31 ` Hugh Dickins
2011-07-12 6:20 ` Wu Fengguang
2011-07-12 19:50 ` Hugh Dickins
2011-07-13 5:49 ` Hugh Dickins
2011-07-13 10:57 ` Hugh Dickins
2011-07-13 11:19 ` Jan Kara
2011-07-13 15:06 ` Hugh Dickins
2011-07-13 22:07 ` Wu Fengguang
2011-06-07 21:32 ` [PATCH 13/15] writeback: remove .nonblocking and .encountered_congestion Wu Fengguang
2011-06-07 21:32 ` [PATCH 14/15] writeback: trace event writeback_single_inode Wu Fengguang
2011-06-07 21:32 ` [PATCH 15/15] writeback: trace event writeback_queue_io Wu Fengguang
2011-06-07 23:04 ` [PATCH 00/15] writeback fixes and cleanups for 3.0 (v5) Andrew Morton
2011-06-08 2:01 ` Wu Fengguang
2011-06-08 6:21 ` Sedat Dilek
2011-06-08 13:45 ` Wu Fengguang
2011-06-09 1:16 ` Stephen Rothwell
2011-06-09 2:18 ` Wu Fengguang
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