Re: [PATCH] i386 rw_semaphores fix

[Andi Kleen]

On Tue, Apr 10, 2001 at 05:55:09PM -0700, Linus Torvalds wrote:
> Note that the "fixup" approach is not necessarily very painful at all,
> from a performance standpoint (either on 386 or on newer CPU's). It's not
> really that hard to just replace the instruction in the "undefined
> instruction"  handler by having strict rules about how to use the "xadd"
> instruction.

Fixup for user space is probably not that nice (CMPXCHG is used there by 
linuxthreads) 

-Andi