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From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Umesh Deshpande <udeshpan@redhat.com>,
	qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [RFC] New thread for the VM migration
Date: Thu, 14 Jul 2011 15:32:50 +0300	[thread overview]
Message-ID: <4E1EE1F2.5020801@redhat.com> (raw)
In-Reply-To: <4E1EE183.5050100@codemonkey.ws>

On 07/14/2011 03:30 PM, Anthony Liguori wrote:
>> Does this mean that the following code is sometimes executed without
>> qemu_mutex? I don't think any of it is thread safe.
>
>
> That was my reaction too.
>
> I think the most rational thing to do is have a separate thread and a 
> pair of producer/consumer queues.
>
> The I/O thread can push virtual addresses and sizes to the queue for 
> the migration thread to compress/write() to the fd.  The migration 
> thread can then push sent regions onto a separate queue for the I/O 
> thread to mark as dirty.

Even virtual addresses are not safe enough, because of hotunplug.  
Without some kind of locking, you have to copy the data.

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

  reply	other threads:[~2011-07-14 12:33 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <539565793.1312156.1310595395982.JavaMail.root@zmail01.collab.prod.int.phx2.redhat.com>
2011-07-13 23:34 ` [Qemu-devel] [RFC] New thread for the VM migration Umesh Deshpande
2011-07-14  7:14   ` Umesh Deshpande
2011-07-14  8:36     ` Avi Kivity
2011-07-14  9:09       ` Stefan Hajnoczi
2011-07-14 12:30       ` Anthony Liguori
2011-07-14 12:32         ` Avi Kivity [this message]
2011-07-14 15:30           ` Juan Quintela
2011-07-14 15:44             ` Avi Kivity
2011-07-14 15:52               ` Juan Quintela
2011-07-14 16:07                 ` Avi Kivity
2011-07-15  7:59                   ` Paolo Bonzini
2011-07-15 21:09                     ` Anthony Liguori
2011-07-17  8:39                     ` Avi Kivity
2011-07-18  7:08                 ` Markus Armbruster
2011-07-14 16:49           ` Anthony Liguori
2011-07-14 16:59             ` Avi Kivity

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