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Date: Fri, 20 Jul 2007 08:45:37 -0700
From: Jeremy Fitzhardinge <jeremy@goop.org>
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To: Andi Kleen <ak@suse.de>
CC: compudj@krystal.dyndns.org, patches@x86-64.org,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [3/11] x86: Stop MCEs and NMIs during code patching
References: <20070720532.949522000@suse.de> <20070720153247.75CAD14E7C@wotan.suse.de>
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Andi Kleen wrote:
> +void stop_nmi(void)
> +{
> +	ignore_nmis++;
> +	acpi_nmi_disable();
> +}
> +
> +void restart_nmi(void)
> +{
> +	ignore_nmis--;
> +	acpi_nmi_enable();
> +}
>   

Wouldn't it be better to just assign ignore_nmis rather than inc/dec it
(and perhaps BUG on a double stop or restart)?  Also, is
acpi_nmi_disable/enable's use of on_each_cpu safe with interrupts
disabled if we know there's only one CPU alive at this point?

    J