On 08/15, NeilBrown wrote: > > de_thread can change the group_leader of a thread_group, and release_task can > remove a non-leader while leaving the rest of the thread_group intact. So > any while_each_thread() loop needs some extra care to ensure that it doesn't > loop infinitely, because the "head" that it is looking for might not be there > any more. > Maybe there are other rules that ensure this can never happen, but they sure > aren't obvious to me (i.e. if you know them - please tell ;-) No, I don't know ;) And note also that if g != leader, then while_each_thread(g, t) can hang simply because g exits. I am still trying to invent something simple to fix while_each_thread-under-rcu. This looks possible, but I am starting to think that, say, zap_threads() needs locking anyway. With any fix I can imagine, it can miss a thread we should care about. Oleg. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
