Re: Why Semaphore Hardware-Dependent?

Ralf Baechle
2006-08-29T16:20:33Z

On Tue, Aug 29, 2006 at 08:56:36AM -0700, Christoph Lameter wrote:

> > Because i386 (and x86_64) can do better by using XADDL/XADDQ.
>
> And Ia64 would like to use fetchadd....
>
> > CMPXCHG is not available on all archs, and may not be implemented on all archs
> > through other atomic instructions.
>
> Which arches do not support cmpxchg?

MIPS, Alpha - probably any pure RISC load/store architecture.

Ralf