Re: [patch 01/23] Fall back on interrupt disable in cmpxchg8b on 80386 and 80486

Christoph Lameter
2007-08-20T20:38:26Z

On Mon, 20 Aug 2007, Mathieu Desnoyers wrote:

> already present in cmpxchg_386_u32 tells much about how this cmpxchg
> implementation should not be used in a SMP context. However, the cmpxchg_local
> can perfectly use this fallback, since it only needs to be atomic wrt the local
> cpu.

Do you have an example where the use of cmpxchg_local is a performance
benefit when actually used in code? cmpxchg is already problematic
functionality since it is not available on all platforms.