On Wed, Aug 15, 2012 at 10:05:28AM +0100, Mel Gorman wrote: > On Tue, Aug 14, 2012 at 05:11:13PM -0300, Rafael Aquini wrote: > > On Tue, Aug 14, 2012 at 10:51:39PM +0300, Michael S. Tsirkin wrote: > > > What I think you should do is use rcu for access. > > > And here sync rcu before freeing. > > > Maybe an overkill but at least a documented synchronization > > > primitive, and it is very light weight. > > > > > > > I liked your suggestion on barriers, as well. > > > > I have not thought about this as deeply as I shouold but is simply rechecking > the mapping under the pages_lock to make sure the page is still a balloon > page an option? i.e. use pages_lock to stabilise page->mapping. To clarify, are you concerned about cost of rcu_read_lock for non balloon pages? > -- > Mel Gorman > SUSE Labs _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
