lkml.org 
[lkml]   [2007]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [REGRESSION] 2.6.19/2.6.20-rc3 buffered write slowdown
On Wed, Jan 10, 2007 at 03:04:15PM -0800, Christoph Lameter wrote:
> On Thu, 11 Jan 2007, David Chinner wrote:
>
> > The performance and smoothness is fully restored on 2.6.20-rc3
> > by setting dirty_ratio down to 10 (from the default 40), so
> > something in the VM is not working as well as it used to....
>
> dirty_background_ratio is left as is at 10?

Yes.

> So you gain performance by switching off background writes via pdflush?

Well, pdflush appears to be doing very little on both 2.6.18 and
2.6.20-rc3. In both cases kswapd is consuming 10-20% of a CPU and
all of the pdflush threads combined (I've seen up to 7 active at
once) use maybe 1-2% of cpu time. This occurs regardless of the
dirty_ratio setting.

Cheers,

Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-01-11 01:07    [W:0.065 / U:0.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site