From: Evgeniy Polyakov <zbr@ioremap.net>
To: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mel@csn.ul.ie>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, Chris Mason <chris.mason@oracle.com>,
Nick Piggin <npiggin@suse.de>, Rik van Riel <riel@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Christoph Hellwig <hch@infradead.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [PATCH 11/12] vmscan: Write out dirty pages in batch
Date: Tue, 15 Jun 2010 14:28:22 +0400 [thread overview]
Message-ID: <20100615102822.GA4010@ioremap.net> (raw)
In-Reply-To: <20100615063643.GS6590@dastard>
On Tue, Jun 15, 2010 at 04:36:43PM +1000, Dave Chinner (david@fromorbit.com) wrote:
> > Nope. Large-number-of-small-files is a pretty common case. If the fs
> > doesn't handle that well (ie: by placing them nearby on disk), it's
> > borked.
>
> Filesystems already handle this case just fine as we see it from
> writeback all the time. Untarring a kernel is a good example of
> this...
>
> I suggested sorting all the IO to be issued into per-mapping page
> groups because:
> a) makes IO issued from reclaim look almost exactly the same
> to the filesytem as if writeback is pushing out the IO.
> b) it looks to be a trivial addition to the new code.
>
> To me that's a no-brainer.
That doesn't coverup large-number-of-small-files pattern, since
untarring subsequently means creating something new, which FS can
optimize. Much more interesting case is when we have dirtied large
number of small files in kind-of random order and submitted them
down to disk.
Per-mapping sorting will not do anything good in this case, even if
files were previously created in a good facion being placed closely and
so on, and only block layer will find a correlation between adjacent
blocks in different files. But with existing queue management it has
quite a small opportunity, and that's what I think Andrew is arguing
about.
--
Evgeniy Polyakov
--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2010-06-15 10:28 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-14 11:17 [PATCH 0/12] Avoid overflowing of stack during page reclaim V2 Mel Gorman
2010-06-14 11:17 ` [PATCH 01/12] tracing, vmscan: Add trace events for kswapd wakeup, sleeping and direct reclaim Mel Gorman
2010-06-14 15:45 ` Rik van Riel
2010-06-14 21:01 ` Larry Woodman
2010-06-14 11:17 ` [PATCH 02/12] tracing, vmscan: Add trace events for LRU page isolation Mel Gorman
2010-06-14 16:47 ` Rik van Riel
2010-06-14 21:02 ` Larry Woodman
2010-06-14 11:17 ` [PATCH 03/12] tracing, vmscan: Add trace event when a page is written Mel Gorman
2010-06-14 16:48 ` Rik van Riel
2010-06-14 21:02 ` Larry Woodman
2010-06-14 11:17 ` [PATCH 04/12] tracing, vmscan: Add a postprocessing script for reclaim-related ftrace events Mel Gorman
2010-06-14 17:55 ` Rik van Riel
2010-06-14 21:03 ` Larry Woodman
2010-06-14 11:17 ` [PATCH 05/12] vmscan: kill prev_priority completely Mel Gorman
2010-06-14 18:04 ` Rik van Riel
2010-06-16 23:37 ` Andrew Morton
2010-06-16 23:45 ` Rik van Riel
2010-06-17 0:18 ` Andrew Morton
2010-06-17 0:34 ` Rik van Riel
2010-06-25 8:29 ` KOSAKI Motohiro
2010-06-28 10:35 ` Mel Gorman
2010-06-14 11:17 ` [PATCH 06/12] vmscan: simplify shrink_inactive_list() Mel Gorman
2010-06-14 18:06 ` Rik van Riel
2010-06-15 10:13 ` Mel Gorman
2010-06-14 11:17 ` [PATCH 07/12] vmscan: Remove unnecessary temporary vars in do_try_to_free_pages Mel Gorman
2010-06-14 18:14 ` Rik van Riel
2010-06-14 11:17 ` [PATCH 08/12] vmscan: Setup pagevec as late as possible in shrink_inactive_list() Mel Gorman
2010-06-14 18:59 ` Rik van Riel
2010-06-15 10:47 ` Christoph Hellwig
2010-06-15 15:56 ` Mel Gorman
2010-06-16 23:43 ` Andrew Morton
2010-06-17 10:30 ` Mel Gorman
2010-06-14 11:17 ` [PATCH 09/12] vmscan: Setup pagevec as late as possible in shrink_page_list() Mel Gorman
2010-06-14 19:24 ` Rik van Riel
2010-06-16 23:48 ` Andrew Morton
2010-06-17 10:46 ` Mel Gorman
2010-06-14 11:17 ` [PATCH 10/12] vmscan: Update isolated page counters outside of main path in shrink_inactive_list() Mel Gorman
2010-06-14 19:42 ` Rik van Riel
2010-06-14 11:17 ` [PATCH 11/12] vmscan: Write out dirty pages in batch Mel Gorman
2010-06-14 21:13 ` Rik van Riel
2010-06-15 10:18 ` Mel Gorman
2010-06-14 23:11 ` Dave Chinner
2010-06-14 23:21 ` Andrew Morton
2010-06-15 0:39 ` Dave Chinner
2010-06-15 1:16 ` Rik van Riel
2010-06-15 1:45 ` Andrew Morton
2010-06-15 4:08 ` Rik van Riel
2010-06-15 4:37 ` Andrew Morton
2010-06-15 5:12 ` Nick Piggin
2010-06-15 5:43 ` [patch] mm: vmscan fix mapping use after free Nick Piggin
2010-06-15 13:23 ` Mel Gorman
2010-06-15 11:01 ` [PATCH 11/12] vmscan: Write out dirty pages in batch Christoph Hellwig
2010-06-15 13:32 ` Rik van Riel
2010-06-15 1:39 ` Andrew Morton
2010-06-15 3:20 ` Dave Chinner
2010-06-15 4:15 ` Andrew Morton
2010-06-15 6:36 ` Dave Chinner
2010-06-15 10:28 ` Evgeniy Polyakov [this message]
2010-06-15 10:55 ` Nick Piggin
2010-06-15 11:10 ` Christoph Hellwig
2010-06-15 11:20 ` Nick Piggin
2010-06-15 23:20 ` Dave Chinner
2010-06-16 6:04 ` Nick Piggin
2010-06-15 11:08 ` Christoph Hellwig
2010-06-15 11:43 ` Mel Gorman
2010-06-15 13:07 ` tytso
2010-06-15 15:44 ` Mel Gorman
2010-06-15 10:57 ` Christoph Hellwig
2010-06-15 10:53 ` Christoph Hellwig
2010-06-15 11:11 ` Mel Gorman
2010-06-15 11:13 ` Nick Piggin
2010-06-14 11:17 ` [PATCH 12/12] vmscan: Do not writeback pages in direct reclaim Mel Gorman
2010-06-14 21:55 ` Rik van Riel
2010-06-15 11:45 ` Mel Gorman
2010-06-15 13:34 ` Rik van Riel
2010-06-15 13:37 ` Christoph Hellwig
2010-06-15 13:54 ` Mel Gorman
2010-06-16 0:30 ` KAMEZAWA Hiroyuki
2010-06-15 14:02 ` Rik van Riel
2010-06-15 13:59 ` Mel Gorman
2010-06-15 14:04 ` Rik van Riel
2010-06-15 14:16 ` Mel Gorman
2010-06-16 0:17 ` KAMEZAWA Hiroyuki
2010-06-16 0:29 ` Rik van Riel
2010-06-16 0:39 ` KAMEZAWA Hiroyuki
2010-06-16 0:53 ` Rik van Riel
2010-06-16 1:40 ` KAMEZAWA Hiroyuki
2010-06-16 2:20 ` KAMEZAWA Hiroyuki
2010-06-16 5:11 ` Christoph Hellwig
2010-06-16 10:51 ` Jens Axboe
2010-06-16 5:07 ` Christoph Hellwig
2010-06-16 5:06 ` Christoph Hellwig
2010-06-17 0:25 ` KAMEZAWA Hiroyuki
2010-06-17 6:16 ` Christoph Hellwig
2010-06-17 6:23 ` KAMEZAWA Hiroyuki
2010-06-14 15:10 ` [PATCH 0/12] Avoid overflowing of stack during page reclaim V2 Christoph Hellwig
2010-06-15 11:45 ` Mel Gorman
2010-06-15 0:08 ` KAMEZAWA Hiroyuki
2010-06-15 11:49 ` Mel Gorman
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=20100615102822.GA4010@ioremap.net \
--to=zbr@ioremap.net \
--cc=akpm@linux-foundation.org \
--cc=chris.mason@oracle.com \
--cc=david@fromorbit.com \
--cc=hannes@cmpxchg.org \
--cc=hch@infradead.org \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mel@csn.ul.ie \
--cc=npiggin@suse.de \
--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).