[Qemu-devel] Re: [patch uq/master 2/2] kvm-all.c: define smp_wmb and use it for coalesced mmio

[Avi Kivity]

On 02/22/2010 05:08 PM, Michael S. Tsirkin wrote:
> > > > I imagine all arches need an instruction.  For reads as well.
> > > >
> > > > Note, gcc has a __sync_synchronize() builtin that compiles to mfence on
> > > > x86.  We might use that as a baseline for both rmb and wmb, and let each
> > > > arch override it incrementally.
> > > >
> > > >          
> > > This it what my patch did. Note it only works well for recent gcc.
> > >
> > >        
> > Do you know how recent?
> >      
> IIRC 4.3 has broken implementation.
> 4.4 seems OK as far as I can tell.
>    

Well, so that idea's down.

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error compiling committee.c: too many arguments to function