All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nick Piggin <npiggin@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org,
	torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
	xfs@oss.sgi.com
Subject: Re: [PATCH 4/6] writeback: pay attention to wbc->nr_to_write in write_cache_pages
Date: Tue, 8 Jun 2010 15:43:30 +1000	[thread overview]
Message-ID: <20100608054330.GS26335@laptop> (raw)
In-Reply-To: <1275957487-23633-5-git-send-email-david@fromorbit.com>

On Tue, Jun 08, 2010 at 10:38:05AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> If a filesystem writes more than one page in ->writepage, write_cache_pages
> fails to notice this and continues to attempt writeback when wbc->nr_to_write
> has gone negative - this trace was captured from XFS:
> 
> 
>     wbc_writeback_start: towrt=1024
>     wbc_writepage: towrt=1024
>     wbc_writepage: towrt=0
>     wbc_writepage: towrt=-1
>     wbc_writepage: towrt=-5
>     wbc_writepage: towrt=-21
>     wbc_writepage: towrt=-85
> 
> This has adverse effects on filesystem writeback behaviour. write_cache_pages()
> needs to terminate after a certain number of pages are written, not after a
> certain number of calls to ->writepage are made.  This is a regression
> introduced by 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 ("vfs: Add
> no_nrwrite_index_update writeback control flag"), but cannot be reverted
> directly due to subsequent bug fixes that have gone in on top of it.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Nick Piggin <npiggin@suse.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

WARNING: multiple messages have this Message-ID (diff)
From: Nick Piggin <npiggin@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, xfs@oss.sgi.com,
	akpm@linux-foundation.org
Subject: Re: [PATCH 4/6] writeback: pay attention to wbc->nr_to_write in write_cache_pages
Date: Tue, 8 Jun 2010 15:43:30 +1000	[thread overview]
Message-ID: <20100608054330.GS26335@laptop> (raw)
In-Reply-To: <1275957487-23633-5-git-send-email-david@fromorbit.com>

On Tue, Jun 08, 2010 at 10:38:05AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> If a filesystem writes more than one page in ->writepage, write_cache_pages
> fails to notice this and continues to attempt writeback when wbc->nr_to_write
> has gone negative - this trace was captured from XFS:
> 
> 
>     wbc_writeback_start: towrt=1024
>     wbc_writepage: towrt=1024
>     wbc_writepage: towrt=0
>     wbc_writepage: towrt=-1
>     wbc_writepage: towrt=-5
>     wbc_writepage: towrt=-21
>     wbc_writepage: towrt=-85
> 
> This has adverse effects on filesystem writeback behaviour. write_cache_pages()
> needs to terminate after a certain number of pages are written, not after a
> certain number of calls to ->writepage are made.  This is a regression
> introduced by 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 ("vfs: Add
> no_nrwrite_index_update writeback control flag"), but cannot be reverted
> directly due to subsequent bug fixes that have gone in on top of it.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Nick Piggin <npiggin@suse.de>


  reply	other threads:[~2010-06-08  5:41 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-08  0:38 [PATCH 0/6] writeback: tracing and fixes V4 Dave Chinner
2010-06-08  0:38 ` Dave Chinner
2010-06-08  0:38 ` [PATCH 1/6] writeback: initial tracing support Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  0:38 ` [PATCH 2/6] writeback: Add tracing to balance_dirty_pages Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  0:38 ` [PATCH 3/6] writeback: Add tracing to write_cache_pages Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  0:38 ` [PATCH 4/6] writeback: pay attention to wbc->nr_to_write in write_cache_pages Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  5:43   ` Nick Piggin [this message]
2010-06-08  5:43     ` Nick Piggin
2010-06-08  0:38 ` [PATCH 5/6] xfs: remove nr_to_write writeback windup Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  0:38 ` [PATCH 6/6] writeback: limit write_cache_pages integrity scanning to current EOF Dave Chinner
2010-06-08  0:38   ` Dave Chinner
2010-06-08  5:38   ` Nick Piggin
2010-06-08  5:38     ` Nick Piggin
2010-06-08  6:59     ` Dave Chinner
2010-06-08  6:59       ` Dave Chinner
2010-06-08  5:44 ` [PATCH 0/6] writeback: tracing and fixes V4 Nick Piggin
2010-06-08  5:44   ` Nick Piggin
2010-06-08 17:41 ` Linus Torvalds
2010-06-08 17:41   ` Linus Torvalds
2010-06-08 17:50   ` Andrew Morton
2010-06-08 17:50     ` Andrew Morton
2010-06-08 22:46   ` Dave Chinner
2010-06-08 22:46     ` Dave Chinner
  -- strict thread matches above, loose matches on Subject: below --
2010-06-03 23:55 [PATCH 0/6] writeback: tracing and fixes V3 Dave Chinner
2010-06-03 23:55 ` [PATCH 4/6] writeback: pay attention to wbc->nr_to_write in write_cache_pages Dave Chinner
2010-06-03 23:55   ` Dave Chinner
2010-06-04  7:48   ` Christoph Hellwig
2010-06-04  7:48     ` Christoph Hellwig
2010-05-25 10:54 [PATCH 0/6] writeback: tracing and fixes Dave Chinner
2010-05-25 10:54 ` [PATCH 4/6] writeback: pay attention to wbc->nr_to_write in write_cache_pages Dave Chinner
2010-05-25 10:54   ` Dave Chinner
2010-05-25 11:11   ` Christoph Hellwig
2010-05-25 11:11     ` Christoph Hellwig
2010-05-27 21:32   ` Andrew Morton
2010-05-27 21:32     ` Andrew Morton
2010-05-28  0:56     ` Dave Chinner
2010-05-28  0:56       ` 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=20100608054330.GS26335@laptop \
    --to=npiggin@suse.de \
    --cc=akpm@linux-foundation.org \
    --cc=david@fromorbit.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=xfs@oss.sgi.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.