Hello, On Wed, Aug 31, 2011 at 03:42:24PM +0200, Frederic Weisbecker wrote: > My task counter subsystem patchset brings a cancel_attach_task() callback > that cancels can_attach_task() effects. > > I thought that rebased on top of your patch it's going to be merged inside > cancel_attach() but OTOH we can't cancel the effect of failed migration > on a thread that way. > > May be we need to keep a cancel_attach_task() just for that purpose? We can do that but I think that becomes a bit too complex and fragile. That path won't be traveled unless it races against exit. Bugs will be difficult to detect and reproduce. In this respect, the current code already seems racy. ->can_attach (or other methods in the attach path) and ->exit can race each other and I don't think all subsystems handle that properly. IMHO the right thing to do here is simplifying synchronization rules so that nothing else happens while migration is in progress. Thanks. -- tejun _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
