Re: [PATCH v7 08/14] KVM: Rename mmu_notifier_*

Peter Zijlstra
2023-05-25T08:55:16Z

On Wed, May 24, 2023 at 02:39:50PM -0700, Sean Christopherson wrote:
> On Wed, May 24, 2023, Peter Zijlstra wrote:
> > On Wed, May 24, 2023 at 01:16:03PM -0700, Sean Christopherson wrote:
> > > Of course, the only accesses outside of mmu_lock are reads, so on x86 that
> > > "atomic" access is just a READ_ONCE() load, but that's not the case for all
> > > architectures.
> >
> > This is true on *all* archs. atomic_set() and atomic_read() are no more
> > and no less than WRITE_ONCE() / READ_ONCE().
>
> Ah, I take it s390's handcoded assembly routines are just a paranoid equivalents
> and not truly special? "l" and "st" do sound quite generic...

Yep, compiler *should* generate the same with READ_ONCE/WRITE_ONCE.