From: Wu Fengguang <fengguang.wu@intel.com>
To: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mel@csn.ul.ie>,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@infradead.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 03/17] writeback: introduce writeback_control.inodes_cleaned
Date: Tue, 10 May 2011 23:00:55 +0800 [thread overview]
Message-ID: <20110510150055.GA7835@localhost> (raw)
In-Reply-To: <20110510135200.GH4402@quack.suse.cz>
On Tue, May 10, 2011 at 09:52:00PM +0800, Jan Kara wrote:
> On Tue 10-05-11 10:23:36, Wu Fengguang wrote:
> > On Fri, May 06, 2011 at 10:36:14PM +0800, Jan Kara wrote:
> > > On Fri 06-05-11 11:08:24, Wu Fengguang wrote:
> > > > The flusher works on dirty inodes in batches, and may quit prematurely
> > > > if the batch of inodes happen to be metadata-only dirtied: in this case
> > > > wbc->nr_to_write won't be decreased at all, which stands for "no pages
> > > > written" but also mis-interpreted as "no progress".
> > > >
> > > > So introduce writeback_control.inodes_cleaned to count the inodes get
> > > > cleaned. A non-zero value means there are some progress on writeback,
> > > > in which case more writeback can be tried.
> > > >
> > > > about v1: The initial version was to count successful ->write_inode()
> > > > calls. However it leads to busy loops for sync() over NFS, because NFS
> > > > ridiculously returns 0 (success) while at the same time redirties the
> > > > inode. The NFS case can be trivially fixed, however there may be more
> > > > hidden bugs in other filesystems..
> > > I think Christoph didn't like this patch
> > > (https://lkml.org/lkml/2011/5/4/123) and suggested that inodes_cleaned
> > > should remain local to fs-writeback.c...
> >
> > Yes, he didn't like introducing one more field to writeback_control,
> > which will be removed in patch 14. (It will be a lot of fuss to move
> > patch 14 here or move this logic after patch 14.)
> Yes, I've noticed (after I've sent this email) that you eventually remove
> the code later in the series :). So I wonder would it be that much work to
> just drop this patch? It's kind of dumb to add a new code which is removed
> a few patches later. But I'm stopping bitching about this now ;).
OK, thanks. I'm just uncomfortable that something will be broken in
between some commits if simply drop this patch :)
Thanks,
Fengguang
next prev parent reply other threads:[~2011-05-10 15:00 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-06 3:08 [PATCH 00/17] writeback fixes and cleanups for 2.6.40 Wu Fengguang
2011-05-06 3:08 ` [PATCH 01/17] writeback: introduce wbc.tagged_sync for the WB_SYNC_NONE sync stage Wu Fengguang
2011-05-06 16:08 ` Jan Kara
2011-05-06 3:08 ` [PATCH 02/17] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang
2011-05-06 16:33 ` Jan Kara
2011-05-10 2:14 ` Wu Fengguang
2011-05-10 12:05 ` Jan Kara
2011-05-06 3:08 ` [PATCH 03/17] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-05-06 14:36 ` Jan Kara
2011-05-10 2:23 ` Wu Fengguang
2011-05-10 13:52 ` Jan Kara
2011-05-10 15:00 ` Wu Fengguang [this message]
2011-05-06 3:08 ` [PATCH 04/17] writeback: try more writeback as long as something was written Wu Fengguang
2011-05-09 16:05 ` Jan Kara
2011-05-10 2:40 ` Wu Fengguang
2011-05-06 3:08 ` [PATCH 05/17] writeback: the kupdate expire timestamp should be a moving target Wu Fengguang
2011-05-06 3:08 ` [PATCH 06/17] writeback: sync expired inodes first in background writeback Wu Fengguang
2011-05-06 19:02 ` Rik van Riel
2011-05-09 16:08 ` Jan Kara
2011-05-09 16:18 ` Rik van Riel
2011-05-10 2:45 ` Wu Fengguang
2011-05-06 3:08 ` [PATCH 07/17] writeback: refill b_io iff empty Wu Fengguang
2011-05-06 3:08 ` [PATCH 08/17] writeback: split inode_wb_list_lock into bdi_writeback.list_lock Wu Fengguang
2011-05-06 3:08 ` [PATCH 09/17] writeback: elevate queue_io() into wb_writeback() Wu Fengguang
2011-05-09 16:15 ` Jan Kara
2011-05-06 3:08 ` [PATCH 10/17] writeback: avoid extra sync work at enqueue time Wu Fengguang
2011-05-09 16:16 ` Jan Kara
2011-05-06 3:08 ` [PATCH 11/17] writeback: add bdi_dirty_limit() kernel-doc Wu Fengguang
2011-05-06 3:08 ` [PATCH 12/17] writeback: skip balance_dirty_pages() for in-memory fs Wu Fengguang
2011-05-06 3:08 ` [PATCH 13/17] writeback: remove writeback_control.more_io Wu Fengguang
2011-05-06 3:08 ` [PATCH 14/17] writeback: make writeback_control.nr_to_write straight Wu Fengguang
2011-05-09 16:54 ` Jan Kara
2011-05-10 3:19 ` Wu Fengguang
2011-05-10 13:44 ` Jan Kara
2011-05-11 14:38 ` Wu Fengguang
2011-05-11 14:54 ` Jan Kara
2011-05-06 3:08 ` [PATCH 15/17] writeback: remove .nonblocking and .encountered_congestion Wu Fengguang
2011-05-06 3:08 ` [PATCH 16/17] writeback: trace event writeback_single_inode Wu Fengguang
2011-05-06 4:16 ` [PATCH 16/17] writeback: trace event writeback_single_inode (v2) Wu Fengguang
2011-05-06 3:08 ` [PATCH 17/17] writeback: trace event writeback_queue_io Wu Fengguang
2011-05-06 4:06 ` [PATCH 00/17] writeback fixes and cleanups for 2.6.40 Anca Emanuel
2011-05-06 4:09 ` Wu Fengguang
-- strict thread matches above, loose matches on Subject: below --
2011-05-12 13:57 [PATCH 00/17] writeback fixes and cleanups for 2.6.40 (v2) Wu Fengguang
2011-05-12 13:57 ` [PATCH 03/17] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-05-12 22:44 ` Dave Chinner
2011-05-13 3:36 ` Wu Fengguang
2011-05-15 23:50 ` Dave Chinner
2011-05-16 10:40 ` Christoph Hellwig
2011-05-16 11:14 ` Wu Fengguang
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