On Fri, Jun 23, 2023 at 8:28 PM Hou Tao <houtao@xxxxxxxxxxxxxxx> wrote: > > > */ > > - obj = __llist_del_first(&c->free_by_rcu_ttrace); > > + obj = llist_del_first(&c->free_by_rcu_ttrace); > According to the comments in llist.h, when there are concurrent > llist_del_first() and llist_del_all() operations, locking is needed. Good question. 1. When only one cpu is doing llist_del_first() locking is not needed. This is the case here. Only this cpu is doing llist_del_first() from this 'c'. 2. The comments doesn't mention it, but llist_del_first() is ok on multiple cpus if ABA problem is addressed by other means. PS please trim your replies.
