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

Christoph Lameter
2006-08-03T05:19:52Z

On Thu, 3 Aug 2006, Andi Kleen wrote:

> > Those operations are only needed for special xen driver and not for
> > regular kernel code!
>
> The Xen driver will be "regular" kernel code.

As far as I can tell from this conversation there are special "Xen"
drivers that need this not the rest of the system.

> > for those special xen drivers.
>
> Well there might be reasons someone else uses this in the future too.
> It's also not exactly Linux style - normally we try to add generic
> facilities.

What possible use could there be to someone else?

The "atomic" ops lock/unlock crap exists only for i386 as far as I can
tell. As you said most architectures either always use atomic ops or
never. The lock/unlock atomic ops are i386 specific material that
better stay contained. Its arch specific and not generic.