On 03/24, Konstantin Khlebnikov wrote: > > On Tue, Mar 24, 2015 at 9:10 PM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > >>> > >>> "atomic_read(&mm->mm_users) <= 1" looks a bit more "safe". But again, > >>> I won't insist. > >> > >> Not so safe: this will race with get_task_mm(). > > > > How? > > I mean rcu/lockdep debug migh race with get_task_mm() and generate > false-positive warning about non-protected rcu_dereference. Still can't understand, I think it can't... and if it could, then this warning would not be false positive. Anut this doesn't matter because we seem to agree this check should go away. > > Yeees, probably rcu_dereference_raw() would be even better. set_mm_exe_file() > > must be called only if nobody but us can access this mm. > > Yep. Great. Davidlohr will you agree? Oleg. -- 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>