Re: [Qemu-devel] [PATCH 1/2] atomics: do not use __atomic primitives for RCU atomics

[Paolo Bonzini]

On 23/05/2016 19:09, Emilio G. Cota wrote:
>               E.
> 
> PS. And really equating smp_wmb/rmb to release/acquire as we have under
> #ifdef __ATOMIC is hard to justify, other than to please tsan.

That only makes a difference on arm64, right?

        acquire         release         rmb             wmb
x86     --              --              --              --
power   lwsync          lwsync          lwsync          lwsync
armv7   dmb             dmb             dmb             dmb
arm64   dmb ishld       dmb ish         dmb ishld       dmb ishst
ia64    --              --              --              --

Thanks,

Paolo