On Tue, 13 Aug 2024 at 12:58, Waiman Long <longman@xxxxxxxxxx> wrote: > > Sorry for the confusion. What you said above is actually the reason that > I ask this question. In the same way, smp_rmb()/wmb() is available for > all arches. I am actually asking if it should be a flag that indicates > the arch's preference to use acquire/release over rmb/wmb. I think that if an arch says it has native acquire/release, we should basically assume that it's the better model. I mean, we could certainly use "PREFERS" instead of "HAS", but is there any real reason to do that? Do we suddenly expect that people would make a CPU that has native acquire/release, and it would somehow then prefer a full read barrier? Linus