From: Christoph Hellwig <hch@lst.de>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 0/3] block: Handle multiple write requests at once
Date: Wed, 2 Sep 2009 17:43:47 +0200 [thread overview]
Message-ID: <20090902154347.GA23891@lst.de> (raw)
In-Reply-To: <4A9E1E4F.4080901@redhat.com>
On Wed, Sep 02, 2009 at 09:27:11AM +0200, Kevin Wolf wrote:
> > Of course using a sane filesystem in the guest would also fix it,
> > but the point of virtualization is at least partially to keep all
> > that old crap working nicely.
>
> Not sure what your definition of "old crap" is, but ext3 seems to meet
> it. I don't think it's irrelevant.
Even ext3 should not do it as the elevator would merge the requests.
Do you happen to run a kernel which accidentally turned on the misnamed
and misguided SSD flag on for virtio? That would explain sending
lots tiny I/Os. You can checks this with a:
cat /sys/block/vd*/queue/rotational
if a 0 turns up somewhere we have the problem.
next prev parent reply other threads:[~2009-09-02 15:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-01 13:51 [Qemu-devel] [PATCH 0/3] block: Handle multiple write requests at once Kevin Wolf
2009-09-01 13:51 ` [Qemu-devel] [PATCH 1/3] Add bdrv_aio_multiwrite Kevin Wolf
2009-09-01 13:51 ` [Qemu-devel] [PATCH 2/3] virtio-blk: Use bdrv_aio_multiwrite Kevin Wolf
2009-09-01 13:51 ` [Qemu-devel] [PATCH 3/3] qcow2: Add bdrv_aio_multiwrite implementation Kevin Wolf
2009-09-01 15:52 ` [Qemu-devel] [PATCH 0/3] block: Handle multiple write requests at once Christoph Hellwig
2009-09-01 16:08 ` Anthony Liguori
2009-09-01 16:14 ` Christoph Hellwig
2009-09-01 17:00 ` Avi Kivity
2009-09-01 16:59 ` Avi Kivity
2009-09-02 7:27 ` Kevin Wolf
2009-09-02 15:43 ` Christoph Hellwig [this message]
2009-09-02 15:50 ` Kevin Wolf
2009-09-02 17:26 ` Christoph Hellwig
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