From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [patch]Add a new reboot method
Date: Thu, 29 May 2008 11:26:45 +0100
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To: "Chen, Huacai" <huacai.chen@intel.com>
Cc: xen-devel@lists.xensource.com, Keir Fraser <keir.fraser@eu.citrix.com>
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> New chipsets support a new reboot method by writing port 0xcf9,

Some new chipsets. What 0xcf9 does to others is undefined.

> sometimes this is more efficient than "keyboard controller reboot" and
> "triple fault reboot". This patch add this new method and use it as a
> preferable one.

Who cares ?

Since when has the number of microseconds per reboot been remotely
relevant. It simply isn't a performance critical path. Besides which you
properly need to use the ACPI power off method on a newer chipset anyway.

(And I would note if Intel really thought power off efficiency was
important then they wouldn't have invented ACPI...)

Alan