Re: [Qemu-devel] [PATCH 0/3] dataplane: virtio-blk live migration with x-data-plane=on

[Andreas Färber]

Hi,

Am 23.07.2013 11:19, schrieb yinyin:
> Hi, Stefan:
>       during the migration, the source, not the destination, will start 
> dataplane again....
>       I think the process of migration with dataplane as follows:
> 1. migration begin to start
> 2. the migration source stop the dataplane
> 3. do migration ...
> 4. migration completed, the destination start the dataplane.

I can't speak for the dataplane, but in general the source guest is
expected to continue working during live migration (that's the "live"
part) until it has been fully transferred to the destination.

HTH,
Andreas

> when migration start, the source dataplane should already stopped, and not 
> start again, if there is no cancel or abort.
> But the trace show that, in step 3 above, the source dataplane will be start 
> by virtio_blk_handle_output. I'm afraid of some inconsistent will happen 
> there.Is it right?
> 
> There is no crash found, I just use this trace to understand the flow of 
> dataplane migration. 
> 
> Yin Yin
> address@hidden
> 
>  
> 在 2013-7-23，下午4:51，Stefan Hajnoczi <address@hidden> 写道：
> 
>> On Fri, Jul 19, 2013 at 01:33:12PM +0800, yinyin wrote:
>>>     I use systemtap to test this patch,the migration will success. But I 
>>> found the dataplane will start again after migration start. the 
>>> virtio_blk_handle_output will start dataplane.
>>
>> Hi Yin Yin,
>> Thank you for testing the patch.  It is not clear to me whether you
>> encountered a problem or not.
>>
>> It is expected that the destination will start the dataplane thread.
>> Was there a crash or some reason why you posted these traces?
>>
>> Stefan
>>
> 
> 


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