Re: Linux 2.6.29
[Posted March 31, 2009 by corbet]
| From: |
| Alan Cox <alan-AT-lxorguk.ukuu.org.uk> |
| To: |
| David Rees <drees76-AT-gmail.com> |
| Subject: |
| Re: Linux 2.6.29 |
| Date: |
| Tue, 24 Mar 2009 09:15:45 +0000 |
| Message-ID: |
| <20090324091545.758d00f5@lxorguk.ukuu.org.uk> |
| Cc: |
| Jesper Krogh <jesper-AT-krogh.cc>,
Linus Torvalds <torvalds-AT-linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel-AT-vger.kernel.org> |
| Archive‑link: | |
Article |
> posted to the list earlier trying to see if there was anything that
> could be done to help my specific case. I've got a system where if
> someone starts writing out a large file, it kills client NFS writes.
> Makes the system unusable:
> http://marc.info/?l=linux-kernel&m=123732127919368&...
I have not had this problem since I applied Arjan's (for some reason
repeatedly rejected) patch to change the ioprio of the various writeback
daemons. Under some loads changing to the noop I/O scheduler also seems
to help (as do most of the non default ones)
> Everyone seems to agree that "autotuning" it is the way to go. But no
> one seems willing to step up and try to do it. Probably because it's
> hard to get right!
If this is a VM problem why does fixing the I/O priority of the various
daemons seem to cure at least some of it ?
Alan
