Re: [patch 2/8] Implement always-locked bit ops, for memory shared with an SMP hypervisor.

Christoph Lameter
2006-08-03T16:50:19Z

On Thu, 3 Aug 2006, Andi Kleen wrote:

> On Thursday 03 August 2006 07:54, Christoph Lameter wrote:
> > On Thu, 3 Aug 2006, Andi Kleen wrote:
> >
> > > > I still wonder why you are so focused on ifdefs. Why would we need those?
> > >
> > > Because the Xen drivers will run on a couple of architectures, including
> > > IA64 and PPC.
> > >
> > > If IA64 or PPC didn't implement at least wrappers for the sync ops
> > > then they would all need special ifdefs to handle this.
> >
> > No they would just need to do an #include <xen-bitops.h>
>
> If IA64 and PPC64 wouldn't have xen-bitops.h (which you seem to argue
> for) then they would need ifdefs.

An include <asm/xen-bitops.h> would need to fall back to asm-generic if
there is no file in asm-arch/xen-bitops.h. I thought we had such a
mechanism?

> You mean into asm-generic/bitops.h? Then it would need ifdefs
> to handle the i386/x86-64 case.

No. Into asm-generic/xen-bitops.h.