Date: Thu, 19 May 2005 01:59:02 +0200
From: Adrian Bunk <bunk@stusta.de>
To: Andi Kleen <ak@muc.de>
Cc: "Gilbert, John" <JGG@dolby.com>, linux-kernel@vger.kernel.org
Subject: Re: Illegal use of reserved word in system.h
Message-ID: <20050518235902.GB5112@stusta.de>
References: <2692A548B75777458914AC89297DD7DA08B0866F@bronze.dolby.net> <m1ll6cyucb.fsf@muc.de>
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On Thu, May 19, 2005 at 01:42:28AM +0200, Andi Kleen wrote:
> "Gilbert, John" <JGG@dolby.com> writes:
> >
> > I think it's been in there a while, but only really blows up when built
> >
> > under recent kernels.
> >
> > I agree, it's probably not the right way to go.
> 
> It's quite dangerous. I suppose it uses this for atomic.h, but it
> means that a mysql compiled under a uniprocessor kernel (or rather
> with a autoconf.h of a uniprocessor kernel, it can even be SMP) will
> have subtle races when run on a SMP system because the atomic
> instructions will miss lock prefixes. Sounds like an open
> deathtrap to me.
>...

They work around this issue by doing

#ifndef CONFIG_SMP
#define CONFIG_SMP
#endif

> -Andi

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

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