Re: [Qemu-devel] [PATCH v2 3/5] migration: do explicit incoming setup for rdma

[Dr. David Alan Gilbert]

* Peter Xu (address@hidden) wrote:
> On Wed, Jun 27, 2018 at 01:25:45PM +0100, Dr. David Alan Gilbert wrote:
> > * Peter Xu (address@hidden) wrote:
> > > RDMA does not support postcopy recovery, so no need to go into such
> > > logic.  Instead of calling migration_fd_process_incoming(), let's call
> > > the two functions that setup the incoming migration.  There should have
> > > no functional change at all.
> > 
> > Can you explain why we need to though?  The reason I ask is that there
> > is Lidong Chen's work that gets postcopy partially working with RDMA, so
> > then the next question is bound to be recovery.
> 
> Ah if so this patch needs to change.  Could you paste me the message
> id of the work?  Or link?
> 
> After all I'll need to keep this bit, but I am just curious about what
> is "partially" mean here. :)

https://patchwork.ozlabs.org/cover/925525/

It enables postcopy with RDMA, but once it switches into postcopy mode
it doesn't use the fast features of RDMA, it still shuffles the data
as a stream (using some more basic RDMA features).

Dave

> Thanks,
> 
> -- 
> Peter Xu
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK