On Fri, 03/13 09:32, Paolo Bonzini wrote:
>
>
> On 13/03/2015 09:16, Fam Zheng wrote:
> >>> > > + if (atomic_cmpxchg(&bounce.in_use, false, true)) {
> >> >
> >> > atomic_or is enough...
> > atomic_cmpxchg is here to take the ownership of bounce iff it is not in
> > use, so
> > I think it is necessary.
>
> It's changing false to true and true to true, so you can do
>
> if (atomic_or(&bounce.in_use, 1)) {
> // was true already
> }I see, we have the old value! Thanks! Fam
