Re: [Qemu-devel] [RFC PATCH RDMA support v4: 08/10] introduce QEMUFileRDMA

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

On 03/20/2013 11:20 AM, Paolo Bonzini wrote:
> Il 19/03/2013 19:40, Paolo Bonzini ha scritto:
>>>>>> That however gives me an idea...  Instead of the full drain at the end
>>>>>> of an iteration, does it make sense to do a "partial" drain at every
>>>>>> chunk full, so that you don't have > N bytes pending and the downtime is
>>>>>> correspondingly limited?
>>>>
>>>> Sure, you could do that, but it seems overly complex just to avoid
>>>> a single flush() call at the end of each iteration, right?
>> Would it really be that complex?  Not having an extra QEMUFile op
>> perhaps balances that complexity (and the complexity remains hidden in
>> rdma.c, which is an advantage).
>>
>> You could alternatively drain every N megabytes sent, or something like
>> that.  But a partial drain would help obeying the maximum downtime
>> limitations.
> On second thought: just keep the drain operation, but make it clear that
> it is related to the new save_ram_page QEMUFileOps field.  You could
> call it flush_ram_pages or something like that.
>
> Paolo
>

Acknowledged. This helps a lot, thank you. I'll be sure to
clearly conditionalize everything in the next RFC.