Re: Pre-approval request for dpkg sync() changes for squeeze
On Sat, 2010-11-06 at 10:41:46 +0100, Sven Joachim wrote:
> On 2010-11-06 08:46 +0100, Guillem Jover wrote:
> > On Fri, 2010-11-05 at 23:18:47 +0100, Philipp Kern wrote:
> > > On Fri, Oct 22, 2010 at 11:35:54AM +0200, Guillem Jover wrote:
> > > What are the implications for ext4 and btrfs?
> >
> > They are going to be slower with this change.
>
> Are you sure this is the case for btrfs? Mike Hommey has described the
> sync() implementation as really horrible[0] (unfortunately the webserver on
> glandium.org is currently down, but the Google cache[1] has a copy).
Buh, yeah, sorry, I meant that to apply only to ext4.
I didn't remember Mike's blog post about btrfs, but Modestas pointed out
in [2] it's twice as worse using sync().
[2] <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=588254>
> For ext4, mounting with the nodelalloc option helps a lot, although this
> option allegedly slows down ext4 in the general case.
Ah right, that was pointed out in a thread recently. This should also
fix any zero-length problems on ext4 too AFAIUI.
> 0. http://glandium.org/blog/?p=1169
> 1. http://webcache.googleusercontent.com/search?q=cache:zFsVyqYwxAAJ:glandium.org/blog/%3Fp%3D1169+mike+hommey+dpkg+sync&cd=1&ct=clnk
thanks,
guillem
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