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Date: Sun, 12 Sep 2010 12:42:36 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 3/3] disk: don't read from disk until the
	guest	starts
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To: Anthony Liguori <aliguori@us.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Juan Quintela <quintela@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

  On 09/11/2010 05:04 PM, Anthony Liguori wrote:
> This fixes a couple nasty problems relating to live migration.
>
> 1) When dealing with shared storage with weak coherence (i.e. NFS), even if
>     we re-read, we may end up with undesired caching.  By delaying any reads
>     until we absolutely have to, we decrease the likelihood of any undesirable
>     caching.
>
> 2) When dealing with copy-on-read, the local storage acts as a cache.  We need
>     to make sure to avoid any reads to avoid polluting the local cache.
>
> +
>   static void ide_identify(IDEState *s)
>   {
>       uint16_t *p;
> @@ -105,6 +132,8 @@ static void ide_identify(IDEState *s)
>   	return;
>       }
>
> +    guess_geometry(s);
> +

This can cause a disk read, no?  Shouldn't it be made asynchronous?

Or just move it to just before the guest starts?

-- 
error compiling committee.c: too many arguments to function