On Mon, May 04, 2020 at 01:16:41PM -0700, Paul E. McKenney wrote: > On Mon, May 04, 2020 at 09:51:28PM +0200, Uladzislau Rezki wrote: > > > > > Since we don't care about traversing backwards, isn't it better to use llist > > > > > for this usecase? > > > > > > > > > > I think Vlad is using locking as we're also tracking the size of the llist to > > > > > know when to free pages. This tracking could suffer from the lost-update > > > > > problem without any locking, 2 lockless llist_add happened simulatenously. > > > > > > > > > > Also if list_head is used, it will take more space and still use locking. > > > > > > > > Indeed, it would be best to use a non-concurrent singly linked list. > > > > > > Ok cool :-) > > > > > > Is it safe to say something like the following is ruled out? ;-) :-D > > > #define kfree_rcu_list_add llist_add > > > > > In that case i think it is better just to add a comment about using > > llist_head. To state that it used as a singular list to save space > > and the access is synchronized by the lock :) > > > > IMHO. > > But adding such a comment would be fine as well. > Thank you Paul and Joel! -- Vlad Rezki
