Re: [PATCH -next v2] locking/osq_lock: annotate a data race in osq_lock

[Qian Cai]

> On May 11, 2020, at 12:54 PM, Will Deacon <w...@kernel.org> wrote:
> 
> Hmm, I don't see how it can remove the cmpxchg(). Do you have a link to that
> discussion, please?

lore.kernel.org/lkml/20200211124753.gp14...@hirez.programming.kicks-ass.net

Correction — if compilers could prove ”prev->next != node” is always true, that 
cmpxchg() would not run. cpu_relax() should be sufficient to keep that “if 
statement” been optimized away in any case.