Re: [Qemu-devel] [PULL 3/3] vhost-user: Attempt to fix a race with set_mem_table.

[Marc-André Lureau]

Hi

----- Original Message -----
> On Fri, Aug 12, 2016 at 03:20:56AM -0400, Marc-André Lureau wrote:
> > Hi
> > 
> > ----- Original Message -----
> > > sent a follow-up response to GET_FEATURES), I am now wondering if this
> > > patch
> > > may break existing vhost applications too ? If so, reverting it possibly
> > > better.
> > > What confuses me is why it doesn’t fail all the time, but only about 20%
> > > to
> > > 30% time as Fam reports.
> > > 
> > > Thoughts : Michael, Fam, MarcAndre ?
> > 
> > Indeed, I didn't ack that patch in the first place for that kind of
> > reasons, so I would revert it.
> > 
> > thanks
> 
> I guess that's the safest thing to do for 2.7.
> At least that's not any worse than 2.6.
> I still think it's a good idea long term and test should be fixed,
> but let's revert for now.
> 

What about other backends that may have similar expectations from the protocol.

This patch is a hack, there is no reason to have it upstream. The solution is 
provided with the REPLY_ACK patch.