[PATCH] arm64: barrier: implement wfe-base smp_cond_load_acquire
peterz at infradead.org
Fri Jun 17 08:42:42 PDT 2016
On Fri, Jun 17, 2016 at 04:38:03PM +0100, Will Deacon wrote:
> > Is there any case where we wouldn't want the memory clobber?
> I don't think you'd need it for cmpwait_relaxed, because the CPU could
> reorder stuff anyway, so anything the compiler does is potentially futile.
> So actually, I can respin this without the clobber. I'll simplify
> the __CMPWAIT_CASE macro to drop the last two parameters as well.
In my previous patches I promoted cmpwait() as a cpu_relax()
'replacement'. Should we not retain the compiler barrier semantics
because of that?
That is, anywhere you use this, you basically _have_ to reread memory,
because the very fact that you return from this basically indicates its
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