Re: [Qemu-devel] [PATCH v4 45/47] Start up a postcopy/listener thread ready for incoming page data

[Dr. David Alan Gilbert]

* David Gibson (address@hidden) wrote:
> On Fri, Oct 03, 2014 at 06:47:51PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> > 
> > The loading of a device state (during postcopy) may access guest
> > memory that's still on the source machine and thus might need
> > a page fill; split off a separate thread that handles the incoming
> > page data so that the original incoming migration code can finish
> > off the device data.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> > ---
> >  include/migration/migration.h |  4 +++
> >  migration.c                   |  6 +++++
> >  savevm.c                      | 62 
> > +++++++++++++++++++++++++++++++++++++++++--
> >  3 files changed, 70 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/migration/migration.h b/include/migration/migration.h
> > index 00255b8..69e776c 100644
> > --- a/include/migration/migration.h
> > +++ b/include/migration/migration.h
> > @@ -92,6 +92,10 @@ struct MigrationIncomingState {
> >      QemuThread     fault_thread;
> >      QemuSemaphore  fault_thread_sem;
> >  
> > +    bool           have_listen_thread;
> 
> AFAICT have_listen_thread is never set to a value other than 'true',
> so there doesn't see much point to it.

It's tested by qemu_loadvm_state to avoid doing cleaning stuff up as it exits,
since the listen thread is still using it.

Dave

> 
> -- 
> David Gibson                  | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au        | minimalist, thank you.  NOT _the_ 
> _other_
>                               | _way_ _around_!
> http://www.ozlabs.org/~dgibson


--
Dr. David Alan Gilbert / address@hidden / Manchester, UK