Messages in this thread | | | Date | Fri, 9 Oct 2015 13:41:28 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v2] barriers: introduce smp_mb__release_acquire and update documentation |
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On Fri, Oct 09, 2015 at 01:02:46PM +0200, Peter Zijlstra wrote: > On Fri, Oct 09, 2015 at 10:40:39AM +0100, Will Deacon wrote: > > Stepping back a second, I believe that there are three cases: > > > > > > RELEASE X -> ACQUIRE Y (same CPU) > > * Needs a barrier on TSO architectures for full ordering > +PPC > > > UNLOCK X -> LOCK Y (same CPU) > > * Needs a barrier on PPC for full ordering > > > > RELEASE X -> ACQUIRE X (different CPUs) > * Fully ordered everywhere... > * ... but needs a barrier on TSO + PPC to become a full barrier > > > UNLOCK X -> ACQUIRE X (different CPUs) > > s/ACQUIRE/LOCK/ ?
Yes, sorry.
Will
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