On Mon, Jun 03, 2019 at 09:33:05AM +0800, Wei Yang wrote: > On Sat, Jun 01, 2019 at 11:34:41AM +0800, Peter Xu wrote: > >On Fri, May 31, 2019 at 05:43:37PM +0100, Dr. David Alan Gilbert wrote: > >> * Wei Yang (richardw.y...@linux.intel.com) wrote: > >> > During migration, we would sync bitmap from ram_list.dirty_memory to > >> > RAMBlock.bmap in cpu_physical_memory_sync_dirty_bitmap(). > >> > > >> > Since we set RAMBlock.bmap and ram_list.dirty_memory both to all 1, this > >> > means at the first round this sync is meaningless and is a duplicated > >> > work. > >> > > >> > Leaving RAMBlock->bmap blank on allocating would have a side effect on > >> > migration_dirty_pages, since it is calculated from the result of > >> > cpu_physical_memory_sync_dirty_bitmap(). To keep it right, we need to > >> > set migration_dirty_pages to 0 in ram_state_init(). > >> > > >> > Signed-off-by: Wei Yang <richardw.y...@linux.intel.com> > >> > >> I've looked at this for a while, and I think it's OK, so > >> > >> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > >> > >> Peter, Juan: Can you just see if there's arny reason this would be bad, > >> but I think it's actually more sensible than what we have. > > > >I really suspect it will work in all cases... Wei, have you done any > >test (or better, thorough tests) with this change? My reasoning of > >why we should need the bitmap all set is here: > > > > I have done some migration cases, like migrate a linux guest through tcp.
When did you start the migration? Have you tried to migrate during some workload? > > Other cases suggested to do? Could you also help answer the question I raised below in the link? Thanks, > >https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg07361.html -- Peter Xu
