Re: cmpxchg in 2.5.38

Geert Uytterhoeven (geert@linux-m68k.org)
Wed, 25 Sep 2002 14:04:48 +0200 (MEST)


On Wed, 25 Sep 2002, Ingo Molnar wrote:
> On Wed, 25 Sep 2002, Oleg Drokin wrote:
> > Ingo's argument was that since there is only one place in code that
> > accesses that variable (map->page), it is safe to rely on such a
> > crippled cmpxchg implementation.
>
> yes. It's only this place in the code that ever modifies that word, and
> that happens only once during the lifetime of this address, so i'll rather
> add a spinlock to the generic PID allocator code, it's a very very rare
> slowpath.

Furthermore archs that have cmpxchg() define __HAVE_ARCH_CMPXCHG, while
currently no code tests for it...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/