From: Wu Fengguang <fengguang.wu@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>, Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mel@csn.ul.ie>,
Christoph Hellwig <hch@infradead.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/18] writeback: sync expired inodes first in background writeback
Date: Fri, 27 May 2011 23:17:32 +0800 [thread overview]
Message-ID: <20110527151732.GA13296@localhost> (raw)
In-Reply-To: <20110525143857.GA25536@localhost>
On Wed, May 25, 2011 at 10:38:57PM +0800, Wu Fengguang wrote:
> On Tue, May 24, 2011 at 11:52:05PM +0800, Jan Kara wrote:
[snip]
> > and I was wondering: Assume there is one continuously redirtied file and
> > untar starts in parallel. With the new logic, background writeback will
> > never consider inodes that are not expired in this situation (we never
> > switch to "all dirty inodes" phase - or even if we switched, we would just
> > queue all inodes and then return back to queueing only expired inodes). So
> > the net effect is that for 30 seconds we will be only continuously writing
> > pages of the continuously dirtied file instead of (possibly older) pages of
> > other files that are written. Is this really desirable? Wasn't the old
> > behavior simpler and not worse than the new one?
>
> Good question! Yes sadly in this case the new behavior could be worse
> than the old one.
Andrew, it's desirable to delay this patch given that it has some
negative behavior (it's fixable but the fix won't be trivial enough
for immediate merge).
You may simply drop this patch (06) and the last two patches (17, 18)
and still be able to cleanly apply all other patches in this series.
Thanks,
Fengguang
next prev parent reply other threads:[~2011-05-27 15:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-24 5:14 [PATCH 00/18] writeback fixes and cleanups for 2.6.40 (v4) Wu Fengguang
2011-05-24 5:14 ` [PATCH 01/18] writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage Wu Fengguang
2011-05-24 5:14 ` [PATCH 02/18] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang
2011-05-24 5:14 ` [PATCH 03/18] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-05-24 5:14 ` [PATCH 04/18] writeback: try more writeback as long as something was written Wu Fengguang
2011-05-24 5:14 ` [PATCH 05/18] writeback: the kupdate expire timestamp should be a moving target Wu Fengguang
2011-05-24 5:14 ` [PATCH 06/18] writeback: sync expired inodes first in background writeback Wu Fengguang
2011-05-24 15:52 ` Jan Kara
2011-05-25 14:38 ` Wu Fengguang
2011-05-26 23:10 ` Jan Kara
2011-05-27 15:06 ` Wu Fengguang
2011-05-27 15:17 ` Wu Fengguang [this message]
2011-05-24 5:14 ` [PATCH 07/18] writeback: refill b_io iff empty Wu Fengguang
2011-05-24 5:14 ` [PATCH 08/18] writeback: split inode_wb_list_lock into bdi_writeback.list_lock Wu Fengguang
2011-05-24 5:14 ` [PATCH 09/18] writeback: elevate queue_io() into wb_writeback() Wu Fengguang
2011-05-24 5:14 ` [PATCH 10/18] writeback: avoid extra sync work at enqueue time Wu Fengguang
2011-05-24 5:14 ` [PATCH 11/18] writeback: add bdi_dirty_limit() kernel-doc Wu Fengguang
2011-05-24 5:14 ` [PATCH 12/18] writeback: skip balance_dirty_pages() for in-memory fs Wu Fengguang
2011-05-24 5:14 ` [PATCH 13/18] writeback: remove writeback_control.more_io Wu Fengguang
2011-05-24 5:14 ` [PATCH 14/18] writeback: remove .nonblocking and .encountered_congestion Wu Fengguang
2011-05-24 5:14 ` [PATCH 15/18] writeback: trace event writeback_single_inode Wu Fengguang
2011-05-24 5:14 ` [PATCH 16/18] writeback: trace event writeback_queue_io Wu Fengguang
2011-05-24 5:14 ` [PATCH 17/18] writeback: make writeback_control.nr_to_write straight Wu Fengguang
2011-05-24 5:14 ` [PATCH 18/18] writeback: rearrange the wb_writeback() loop Wu Fengguang
2011-05-29 7:34 ` [PATCH 00/18] writeback fixes and cleanups for 2.6.40 (v4) Sedat Dilek
-- strict thread matches above, loose matches on Subject: below --
2011-05-19 21:45 [PATCH 00/18] writeback fixes and cleanups for 2.6.40 (v3) Wu Fengguang
2011-05-19 21:45 ` [PATCH 06/18] writeback: sync expired inodes first in background writeback Wu Fengguang
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