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Message-ID: <a2ebde260609100723v553d3810o1651dc181e7db3bf@mail.gmail.com>
Date: Sun, 10 Sep 2006 22:23:05 +0800
From: "Dong Feng" <middle.fengdong@gmail.com>
To: "Andi Kleen" <ak@suse.de>
Subject: Re: Timer Selection
Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>, linux-kernel@vger.kernel.org
In-Reply-To: <200609101551.11521.ak@suse.de>
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	 <200609101551.11521.ak@suse.de>
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Thank you very much.


2006/9/10, Andi Kleen <ak@suse.de>:
> On Sunday 10 September 2006 12:34, Dong Feng wrote:
> > In i386 architecture, there are five timers as candidates in the selection
> > of "cur_timer." I feel among the five only two types can be used as Kernel
> > base timer, HPET and PIT. Kernel base timer is the timer trigger
> > timer_interrupt() periodically. Namely, the timer installed on IRQ 0 in
> > i386 architecture.
> >
> > Is the above understanding correct? Particularly I want to confirm which
> > timers can be used as Kernel base timer.
>
> Only HPET and PIT can be interrupt 0 in the PC architecture
> (HPET only if the legacy option is available), but there is no reason
> the main timer handler cannot be driven from another interval timer (e.g.
> x86-64 offers the APIC timer as a option for this)
>
> -Andi
>