From: Wu Fengguang <fengguang.wu@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>, Mel Gorman <mel@linux.vnet.ibm.com>,
Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mel@csn.ul.ie>,
Itaru Kitayama <kitayama@cl.bb4u.ne.jp>,
Minchan Kim <minchan.kim@gmail.com>,
Linux Memory Management List <linux-mm@kvack.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 5/6] writeback: sync expired inodes first in background writeback
Date: Thu, 21 Apr 2011 09:21:56 +0800 [thread overview]
Message-ID: <20110421012156.GA11120@localhost> (raw)
In-Reply-To: <20110421011431.GA7828@localhost>
> > Are you testing for this failure scenario? If so, can you briefly
> > describe the testing?
>
> Not yet.. But one possible scheme is to record the dirty time of each
> page in a debug kernel and expose them to user space. Then we can run
> any kind of workloads, and in the mean while run a background scanner
> to collect and report the distribution of dirty page ages.
>
> Does it sound too heavy weight? Or we may start by reporting the dirty
> inode age first. To maintain a mapping->writeback_index_wrapped_when and
> a mapping->pages_dirtied_when to follow it (or just reuse/reset
> mapping->dirtied_when?). The former will be reset to jiffies on each
> full scan of the pages. range_whole=1 scan can maintain its start time
> in a local variable. Then we get an estimation "what's the max
> possible dirty page age this inode has?". There will sure be redirtied
> pages though..
Hmm the lighter scheme will fail the common "active sequential write
to large file" case, because the full scan will never manage to come
to an end..
Thanks,
Fengguang
--
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 1:22 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-20 8:03 [PATCH 0/6] writeback: moving expire targets for background/kupdate works v2 Wu Fengguang
2011-04-20 8:03 ` [PATCH 1/6] writeback: pass writeback_control down to move_expired_inodes() Wu Fengguang
2011-05-04 11:04 ` Christoph Hellwig
2011-05-04 11:13 ` Wu Fengguang
2011-04-20 8:03 ` [PATCH 2/6] writeback: introduce writeback_control.inodes_cleaned Wu Fengguang
2011-05-04 11:05 ` Christoph Hellwig
2011-05-04 11:11 ` Wu Fengguang
2011-05-04 11:16 ` Christoph Hellwig
2011-05-04 11:32 ` Wu Fengguang
2011-04-20 8:03 ` [PATCH 3/6] writeback: try more writeback as long as something was written Wu Fengguang
2011-04-20 8:03 ` [PATCH 4/6] writeback: the kupdate expire timestamp should be a moving target Wu Fengguang
2011-04-20 8:03 ` [PATCH 5/6] writeback: sync expired inodes first in background writeback Wu Fengguang
2011-04-20 23:40 ` Andrew Morton
2011-04-21 1:14 ` Wu Fengguang
2011-04-21 1:21 ` Wu Fengguang [this message]
2011-04-24 3:15 ` Wu Fengguang
2011-04-26 12:17 ` Jan Kara
2011-04-26 13:51 ` Wu Fengguang
2011-04-26 13:59 ` Wu Fengguang
2011-04-26 14:05 ` Wu Fengguang
2011-04-27 11:15 ` Wu Fengguang
2011-04-20 8:03 ` [PATCH 6/6] writeback: refill b_io iff empty Wu Fengguang
2011-05-04 7:39 ` Wu Fengguang
2011-05-05 16:37 ` Jan Kara
2011-05-05 16:47 ` Wu Fengguang
2011-05-06 5:29 ` Wu Fengguang
2011-05-06 8:42 ` [RFC][PATCH] writeback: limit number of moved inodes in queue_io() Wu Fengguang
2011-05-06 10:06 ` [RFC][PATCH v2] " Wu Fengguang
2011-05-06 23:06 ` Dave Chinner
2011-05-06 14:21 ` [PATCH 6/6] writeback: refill b_io iff empty Jan Kara
2011-05-10 4:31 ` Wu Fengguang
2011-05-10 4:53 ` Dave Chinner
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=20110421012156.GA11120@localhost \
--to=fengguang.wu@intel.com \
--cc=akpm@linux-foundation.org \
--cc=david@fromorbit.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@csn.ul.ie \
--cc=mel@linux.vnet.ibm.com \
--cc=minchan.kim@gmail.com \
--cc=riel@redhat.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).