From: Dave Chinner <david@fromorbit.com>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mel@linux.vnet.ibm.com>,
Trond Myklebust <Trond.Myklebust@netapp.com>,
Itaru Kitayama <kitayama@cl.bb4u.ne.jp>,
Minchan Kim <minchan.kim@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [PATCH 5/6] writeback: try more writeback as long as something was written
Date: Thu, 21 Apr 2011 17:09:47 +1000 [thread overview]
Message-ID: <20110421070947.GA12436@dastard> (raw)
In-Reply-To: <20110421033325.GA13764@localhost>
On Thu, Apr 21, 2011 at 11:33:25AM +0800, Wu Fengguang wrote:
> I collected the writeback_single_inode() traces (patch attached for
> your reference) each for several test runs, and find much more
> I_DIRTY_PAGES after patchset. Dave, do you know why there are so many
> I_DIRTY_PAGES (or radix tag) remained after the XFS ->writepages() call,
> even for small files?
>
> wfg /tmp% g -c I_DIRTY_PAGES trace-*
> trace-moving-expire-1:28213
> trace-no-moving-expire:6684
>
> wfg /tmp% g -c I_DIRTY_DATASYNC trace-*
> trace-moving-expire-1:179
> trace-no-moving-expire:193
>
> wfg /tmp% g -c I_DIRTY_SYNC trace-*
> trace-moving-expire-1:29394
> trace-no-moving-expire:31593
>
> wfg /tmp% wc -l trace-*
> 81108 trace-moving-expire-1
> 68562 trace-no-moving-expire
Likely just timing. When IO completes and updates the inode IO size,
XFS calls mark_inode_dirty() again to ensure that the metadata that
was changed gets written out at a later point in time.
Hence every single file that is created by the test will be marked
dirty again after the first write has returned and disappeared.
Why you see different numbers? it's timing dependent based on Io
completion rates - if you have a fast disk the IO completion can
occur before write_inode() is called and so the inode can be written
and the dirty page state removed in the one writeback_single_inode()
call...
That's my initial guess without looking at it in any real detail,
anyway.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-04-21 7:09 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-19 3:00 [PATCH 0/6] writeback: moving expire targets for background/kupdate works Wu Fengguang
2011-04-19 3:00 ` [PATCH 1/6] writeback: pass writeback_control down to move_expired_inodes() Wu Fengguang
2011-04-19 3:00 ` [PATCH 2/6] writeback: the kupdate expire timestamp should be a moving target Wu Fengguang
2011-04-19 7:02 ` Dave Chinner
2011-04-19 7:20 ` Wu Fengguang
2011-04-19 9:31 ` Jan Kara
2011-04-19 3:00 ` [PATCH 3/6] writeback: sync expired inodes first in background writeback Wu Fengguang
2011-04-19 7:35 ` Dave Chinner
2011-04-19 9:57 ` Jan Kara
2011-04-19 12:56 ` Wu Fengguang
2011-04-19 13:46 ` Wu Fengguang
2011-04-20 1:21 ` Dave Chinner
2011-04-20 2:53 ` Wu Fengguang
2011-04-21 0:45 ` Dave Chinner
2011-04-21 2:06 ` Wu Fengguang
2011-04-21 3:01 ` Dave Chinner
2011-04-21 3:59 ` Wu Fengguang
2011-04-21 4:10 ` Wu Fengguang
2011-04-21 4:36 ` Christoph Hellwig
2011-04-21 6:36 ` Dave Chinner
2011-04-21 16:04 ` Jan Kara
2011-04-22 2:24 ` Wu Fengguang
2011-04-22 21:12 ` Jan Kara
2011-04-26 5:37 ` Wu Fengguang
2011-04-26 14:30 ` Jan Kara
2011-04-20 7:38 ` Wu Fengguang
2011-04-21 1:01 ` Dave Chinner
2011-04-21 1:47 ` Wu Fengguang
2011-04-19 3:00 ` [PATCH 4/6] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-04-19 9:47 ` Jan Kara
2011-04-19 3:00 ` [PATCH 5/6] writeback: try more writeback as long as something was written Wu Fengguang
2011-04-19 10:20 ` Jan Kara
2011-04-19 11:16 ` Wu Fengguang
2011-04-19 21:10 ` Jan Kara
2011-04-20 7:50 ` Wu Fengguang
2011-04-20 15:22 ` Jan Kara
2011-04-21 3:33 ` Wu Fengguang
2011-04-21 4:39 ` Christoph Hellwig
2011-04-21 6:05 ` Wu Fengguang
2011-04-21 16:41 ` Jan Kara
2011-04-22 2:32 ` Wu Fengguang
2011-04-22 21:23 ` Jan Kara
2011-04-21 7:09 ` Dave Chinner [this message]
2011-04-21 7:14 ` Christoph Hellwig
2011-04-21 7:52 ` Dave Chinner
2011-04-21 8:00 ` Christoph Hellwig
2011-04-19 3:00 ` [PATCH 6/6] NFS: return -EAGAIN when skipped commit in nfs_commit_unstable_pages() Wu Fengguang
2011-04-19 3:29 ` Trond Myklebust
2011-04-19 3:55 ` Wu Fengguang
2011-04-21 4:40 ` Christoph Hellwig
2011-04-19 6:38 ` [PATCH 0/6] writeback: moving expire targets for background/kupdate works Dave Chinner
2011-04-19 8:02 ` Wu Fengguang
2011-04-21 4:34 ` Christoph Hellwig
2011-04-21 5:50 ` Wu Fengguang
2011-04-21 5:56 ` Christoph Hellwig
2011-04-21 6:07 ` Wu Fengguang
2011-04-21 7:17 ` Christoph Hellwig
2011-04-21 10:15 ` Wu Fengguang
-- strict thread matches above, loose matches on Subject: below --
2010-07-22 5:09 [PATCH 0/6] [RFC] writeback: try to write older pages first Wu Fengguang
2010-07-22 5:09 ` [PATCH 5/6] writeback: try more writeback as long as something was written Wu Fengguang
2010-07-23 17:39 ` Jan Kara
2010-07-26 12:39 ` Wu Fengguang
2010-07-26 11:01 ` Mel Gorman
2010-07-26 11:39 ` Wu Fengguang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110421070947.GA12436@dastard \
--to=david@fromorbit.com \
--cc=Trond.Myklebust@netapp.com \
--cc=akpm@linux-foundation.org \
--cc=fengguang.wu@intel.com \
--cc=jack@suse.cz \
--cc=kitayama@cl.bb4u.ne.jp \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mel@linux.vnet.ibm.com \
--cc=minchan.kim@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).