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Re: [Xen-devel] [PATCH] Segments can span multiple clusters withtap:qcow

To: Keir Fraser <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Segments can span multiple clusters withtap:qcow
From: Mark McLoughlin <markmc@xxxxxxxxxx>
Date: Thu, 03 May 2007 18:47:49 +0100
Cc: Jake Wires <Jake.Wires@xxxxxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
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On Thu, 2007-05-03 at 18:40 +0100, Keir Fraser wrote:
> On 3/5/07 02:06, "Jake Wires" <Jake.Wires@xxxxxxxxxxxxx> wrote:
> > This patch is back to only allocating enough requests for one segment:
> > 
> > +        /* A segment (i.e. a page) can span multiple clusters */
> > +        s->max_aio_reqs = (getpagesize() / s->cluster_size) + 1;
> > 
> > In fact, this code allocates exactly two AIO requests for QCoW images
> > created by qcow-create, which have a default cluster size of 4K.
> What shall we do -- revert the whole patch or fix this line?

        Goodness, words fail me. In all the confusion I created, that fix got
lost again. It should be:

+        s->max_aio_reqs = ((getpagesize() / s->cluster_size) + 1) * 


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