Re: [Qemu-devel] [RFC 4/6] migration: move dirty bitmap sync to ram_addr.h

[Stefan Hajnoczi]

On Thu, Nov 27, 2014 at 04:29:06PM +0000, Dr. David Alan Gilbert wrote:
> * Stefan Hajnoczi (address@hidden) wrote:
> > The dirty memory bitmap is managed by ram_addr.h and copied to
> > migration_bitmap[] periodically during live migration.
> > 
> > Move the code to sync the bitmap to ram_addr.h where related code lives.
> 
> Is this sync code going to need to gain a barrier (although I'm not quite
> sure which) to ensure it's picked up all changes?

gcc makes these operations a full barrier:
https://gcc.gnu.org/onlinedocs/gcc-4.1.1/gcc/Atomic-Builtins.html

Stefan

pgpgk4IbOxBmS.pgp
Description: PGP signature