Messages in this thread | | | Date | Thu, 1 Feb 2018 16:50:07 +0100 | From | Peter Zijlstra <> | Subject | Re: asm-generic: Disallow no-op mb() for SMP systems |
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On Thu, Feb 01, 2018 at 03:39:51PM +0000, Will Deacon wrote: > > I could've gotten my brain in a twist or course, which isn't _that_ > > unusual. I never seem to be able to quite remember the holes you have > > with ll/sc on arm64 :-) > > Is smp_mb__before_atomic supposed to provide ordering guarantees if it's > used before a failed cmpxchg? If so, I think it's needed here because the > l.swa might not even execute. Or did I just invent another problem?
I think it should do so indeed (and afaik all our current archs are good that way).
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