On 20/06/2018 00:42, Junaid Shahid wrote: > Actually, now that I think about it again, I don't think that any > read barrier is needed here. I don't believe that the scenario that I > described in the comments in this patch needs a read barrier (though > please correct me if that isn't the case). The code path that I > actually had in mind when putting the barrier here appears to already > include a read barrier that I missed seeing earlier. > > In any case, it seems that smp_read_barrier_depends() is a no-op on > x86. So we can just remove it altogether, unless you think that it > would be useful to keep it just as documentation. It's not entirely a no-op, it's (on x86) a compiler optimization barrier. In the comment above smp_wmb you should say what is the read barrier that is "paired" with the smp_wmb. If there is none, that most likely means that the smp_read_barrier_depends _is_ actually needed. Paolo
