Re: [Qemu-devel] [RFC PATCH RDMA support v5: 03/12] comprehensive protocol documentation

[Michael S. Tsirkin]

On Thu, Apr 11, 2013 at 05:33:41PM +0200, Paolo Bonzini wrote:
> Il 11/04/2013 17:18, Michael R. Hines ha scritto:
> > First of all, this whole argument should not even exist for the 
> > following reason:
> > 
> > Page registrations are supposed to be *rare* - once a page is 
> > registered, it is registered for life.
> 
> Uh-oh.  That changes things a lot.  We do not even need to benchmark the
> various chunk sizes.
> 
> > Third, this means that optimizing this protocol would not be helpful
> > and that we should follow the "keep it simple" approach because
> > during steady-state phase of the migration most of the pages should
> > have already been registered.
> 
> Ok, let's keep it simple.  The only two things we need are:
> 
> 1) remove the patch to disable is_dup_page
> 
> 2) rename the transport to "x-rdma" (just in migration.c)
> 
> Both things together let us keep it safe for a release or two.  Let's
> merge this thing.
> 
> Paolo

I would drop the chunk based thing too.  Besides being slow, it turns
out that it pins all memory anyway. So no memory overcommit.

-- 
MST