Messages in this thread |  | | Date | Wed, 15 Aug 2012 12:25:28 +0300 | | From | "Michael S. Tsirkin" <> | | Subject | Re: [PATCH v7 2/4] virtio_balloon: introduce migration primitives to balloon pages |
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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
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