Date: Thu, 30 Apr 2009 09:32:44 -0500
From: Clark Williams <williams@redhat.com>
To: "Mao Yilu" <ylmao@mail.ustc.edu.cn>
Cc: "'Henrique de Moraes Holschuh'" <hmh@hmh.eng.br>,
       <linux-kernel@vger.kernel.org>
Subject: Re: TSC unstable on Intel Pentium M processor 750
Message-ID: <20090430093244.74fcb1af@torg>
In-Reply-To: <441077283.08393@ustc.edu.cn>
References: <440758024.12507@ustc.edu.cn>
	<441049102.10204@ustc.edu.cn>
	<654E14825BCE4C9B94E5986000DC9BCE@xiaomao>
	<441061189.03958@ustc.edu.cn>
	<441077283.08393@ustc.edu.cn>
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On Thu, 30 Apr 2009 15:40:02 +0800
"Mao Yilu" <ylmao@mail.ustc.edu.cn> wrote:

> > -----Original Message-----
> > From: linux-kernel-owner@vger.kernel.org
> > [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Henrique de Moraes
> > Holschuh
> > Sent: Thursday, April 30, 2009 11:12 AM
> > To: Mao Yilu
> > Cc: 'Robert Hancock'; linux-kernel@vger.kernel.org
> > Subject: Re: TSC unstable on Intel Pentium M processor 750
> > 
> > On Thu, 30 Apr 2009, Mao Yilu wrote:
> > > But I still don't know why the TSC is not correct in the C1 state (hlt
> > > instruction). Is there anything more to influence the TSC? What happened
> > > when the CPU is not running under hlt instruction?
> > 
> > SMIs?  Laptops love that crap...
> 
> What is SMIs?
> 
>

System Management Interrupt. Usually handled by BIOS code and
completely invisible to Linux. 

Laptops and big servers (rackmount/blades) typically have tons of SMIs
going off to do thermal management, statisics and remote management.

Clark
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