Re: [PATCH] WorkStruct: Implement generic UP cmpxchg() where an arch doesn't support it

David Miller
2006-12-07T01:09:04Z

From: Al Viro <viro@ftp.linux.org.uk>
Date: Wed, 6 Dec 2006 19:08:28 +0000

> On Wed, Dec 06, 2006 at 11:05:22AM -0800, Linus Torvalds wrote:
> >
> >
> > On Wed, 6 Dec 2006, Christoph Lameter wrote:
> > >
> > > I'd really appreciate a cmpxchg that is generically available for
> > > all arches. It will allow lockless implementation for various performance
> > > criticial portions of the kernel.
> >
> > I suspect ARM may have been the last one without one, no?
>
> No. sparc32 doesn't have one, for instance.

That's correct. It has an atomic swap, but not a cmpxchg.