On Tue, 2014-05-06 at 12:18 -0400, Jerome Glisse wrote: > > I do understand that i was pointing out that if i move to, tlb which i > am fine with, i will still need to sleep there. That's all i wanted to > stress, i did not wanted force using mmu_notifier, i am fine with them > becoming atomic as long as i have a place where i can intercept cpu > page table update and propagate them to device mmu. Your MMU notifier can maintain a map of "dirty" PTEs and you do the actual synchronization in the subsequent flush_tlb_* , you need to add hooks there but it's much less painful than in the notifiers. *However* Linus, even then we can't sleep. We do things like ptep_clear_flush() that need the PTL and have the synchronous flush semantics. Sure, today we wait, possibly for a long time, with IPIs, but we do not sleep. Jerome would have to operate within a similar context. No sleep for you :) Cheers, Ben. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>