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Date: Tue, 11 Apr 2006 20:04:36 -0700
From: "Joshua Hudson" <joshudson@gmail.com>
To: lepton <ytht.net@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: 386/smp issue with atomic_add_return()
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On 4/11/06, lepton <ytht.net@gmail.com> wrote:
> Hi
>         Is there any smp box with 386 cpu?
>         If it exist, then I think atomic_add_return has a problem.
>         Just disabling local interrupts can not keep another cpu from entering this function.
>         What do you think about this?
>
>         This is the code (copied from 2.6.16.4):
>
>         #ifdef CONFIG_M386
>  no_xadd: /* Legacy 386 processor */
>         local_irq_disable();
>         __i = atomic_read(v);
>         atomic_set(v, i + __i);
>         local_irq_enable();
>         return i + __i;
>         #endif

If such a box exists (and I doubt), it is not a commody PC.
First x86 SMP motherboard I heard of was a P1 with two processors.