Re: [PATCH 6/6] vmscan: Do not writeback pages in direct reclaim

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 11 Jun 2010 12:25:23 -0400 Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:

> On Thu, Jun 10, 2010 at 11:17:06PM -0700, Andrew Morton wrote:
> > As it stands, it would be wildly incautious to make a change like
> > this without first working out why we're pulling so many dirty pages
> > off the LRU tail, and fixing that.
> 
> Note that unlike the writepage vs writepages from kswapd which can
> be fixed by the right tuning this is a black or white issue.  Writeback
> from direct reclaim will kill your stack if the caller happens to be
> the wrong one, and just making it happen less often is not a fix - it
> must not happen at all.

Of course, but making a change like that in the current VM will cause a
large number of dirty pages to get refiled, so the impact of this
change on some workloads could be quite bad.

If, however, we can get things back to the state where few dirty pages
ever reach the tail of the LRU then the adverse impact of this change
will be much less.

--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux