Re: [PATCH] LoongArch: Fixup cmpxchg sematic for memory barrier

From: WANG Rui
Date: Tue Aug 01 2023 - 12:37:16 EST

On Tue, Aug 1, 2023 at 6:50 PM Guo Ren <guoren@xxxxxxxxxx> wrote:
> On Tue, Aug 1, 2023 at 5:32 PM WANG Rui <wangrui@xxxxxxxxxxx> wrote:
> > No. LL and LL won't reorder because LL implies a memory barrier(though
> > not acquire semantics).
> That means we could remove __WEAK_LLSC_MB totally, right?

More precisely, __WEAK_LLSC_MB is intended to prevent reordering
between LL and normal LD used to fetch the expected value for cmpxchg.