From: Jamie Lokier <jamie@shareable.org>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] buffer alignment for block backends
Date: Thu, 9 Apr 2009 16:55:50 +0100 [thread overview]
Message-ID: <20090409155550.GA14196@shareable.org> (raw)
In-Reply-To: <20090409152107.GE5457@const.bordeaux.inria.fr>
Samuel Thibault wrote:
> Gerd Hoffmann, le Thu 09 Apr 2009 15:54:34 +0200, a écrit :
> > On 04/09/09 15:30, Stefano Stabellini wrote:
> > >The userspace\kernelspace distinction does not make much sense in
> > >minios, but yes it provides an interface to communicate with blkback in
> > >dom0. This interface is used by block-vbd in qemu instead of
> > >block-raw-posix when run in minios.
> >
> > Sit back, look again. Do you really need it being page-aligned?
>
> Page aligned is an optimization which comes for free when you can
> already choose the alignment.
>
> > The xen block protocol can handle unaligned requests just fine.
>
> Not completely arbitrarily aligned requests. They need to be
> sector-aligned.
Thought about 4k sectors, to be found in new disks sometime soon?
-- Jamie
next prev parent reply other threads:[~2009-04-09 15:55 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-08 13:35 [Qemu-devel] buffer alignment for block backends Stefano Stabellini
2009-04-08 18:53 ` Anthony Liguori
2009-04-09 9:57 ` Stefano Stabellini
2009-04-09 13:11 ` Anthony Liguori
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 13:54 ` Gerd Hoffmann
2009-04-09 15:21 ` Samuel Thibault
2009-04-09 15:46 ` Stefano Stabellini
2009-04-09 15:50 ` Gerd Hoffmann
2009-04-09 16:11 ` Stefano Stabellini
2009-04-09 16:13 ` Samuel Thibault
2009-04-09 16:28 ` Anthony Liguori
2009-04-09 15:55 ` Jamie Lokier [this message]
2009-04-09 16:15 ` Samuel Thibault
2009-04-09 17:29 ` Lennart Sorensen
2009-04-09 13:33 ` Stefano Stabellini
2009-04-09 15:19 ` Samuel Thibault
2009-04-09 15:38 ` Paul Brook
2009-04-09 15:40 ` Samuel Thibault
2009-04-09 15:56 ` Anthony Liguori
2009-04-09 16:19 ` Samuel Thibault
2009-04-09 10:07 ` Stefano Stabellini
2009-04-09 13:14 ` Anthony Liguori
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 13:19 ` Christoph Hellwig
2009-04-09 13:30 ` Stefano Stabellini
2009-04-09 15:31 ` Christoph Hellwig
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