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

[Paolo Bonzini]

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