Subject: Re: [PATCH 08/10] x86-32: support atomic64_t on 386/486 UP/SMP
From: Peter Zijlstra <peterz@infradead.org>
To: Luca Barbieri <luca@luca-barbieri.com>
Cc: mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org,
       linux-kernel@vger.kernel.org
In-Reply-To: <1266406962-17463-9-git-send-email-luca@luca-barbieri.com>
References: <1266406962-17463-1-git-send-email-luca@luca-barbieri.com>
	 <1266406962-17463-9-git-send-email-luca@luca-barbieri.com>
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Date: Thu, 18 Feb 2010 11:25:46 +0100
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On Wed, 2010-02-17 at 12:42 +0100, Luca Barbieri wrote:
> This patch makes atomic64 use either the generic implementation or
> the rewritten cmpxchg8b one just introduced by inserting a "call" to
> either, using the alternatives system to dynamically switch the calls.
> 
> This allows to use atomic64_t on 386/486 which lack cmpxchg8b

IIRC we dropped <i586 SMP support, and since we don't have a PMU on
those chips atomic64_t doesn't need to be NMI safe, so a simple
UP-IRQ-disable implementation should suffice.

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