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Date: Wed, 25 Sep 2002 14:04:48 +0200 (MEST)
From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Ingo Molnar <mingo@elte.hu>
cc: Oleg Drokin <green@namesys.com>, "David S. Miller" <davem@redhat.com>,
       zaitcev@redhat.com, mingo@redhat.com,
       Linux Kernel Development <linux-kernel@vger.kernel.org>
Subject: Re: cmpxchg in 2.5.38
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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