----- On Sep 4, 2019, at 12:11 PM, Oleg Nesterov [email protected] wrote: > with or without these changes... > > Why do membarrier_register_*_expedited() check get_nr_threads() == 1? > This makes no sense to me, atomic_read(mm_users) == 1 should be enough. > > > And I am not sure I understand membarrier_mm_sync_core_before_usermode(). > OK, membarrier_private_expedited() can race with user -> kernel -> user > transition, but we do not care unless both user's above have the same mm? > Shouldn't membarrier_mm_sync_core_before_usermode() do > > if (current->mm != mm) > return; > > at the start to make it more clear and avoid sync_core_before_usermode() > if possible?
I think I missed replying to your email. Indeed, you are right, I've added 2 cleanup patches taking care of this in my latest round. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
