From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: TM1/TM2 Date: Mon, 2 Oct 2006 12:08:17 -0400 Message-ID: <20061002160817.GE23268@redhat.com> References: <4520F84C.6090604@slagter.name> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <4520F84C.6090604@slagter.name> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=gmane.org+glkc-cpufreq=gmane.org@lists.linux.org.uk Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Erik Slagter Cc: cpufreq On Mon, Oct 02, 2006 at 01:30:20PM +0200, Erik Slagter wrote: > Hi, > > Is there a reliable way to know whether tm1/tm2 and/or other throttling > have been applied by the hardware? > > I am very suspicious that my cpu does tm1 or tm2 once in a while, but I > can't prove it. It doesn't seem to be reported via MCE, which I'd expect. > > FWIW I have a Pentium D915 and it has eist and tm1/tm2 (although linux > says only tm1), all enabled in the BIOS. Thermal monitoring isn't actually handled by cpufreq, but by the mcheck code (arch/i386/kernel/cpu/mcheck/p4.c) It appears that if it is in use it does the following printk's.. printk(KERN_EMERG "CPU%d: Temperature above threshold\n", cpu); printk(KERN_EMERG "CPU%d: Running in modulated clock mode\n", So if you haven't seen those, it isn't in effect. The only other thermal throttling is that provided by the p4-clockmod module, which will scale regardless of temperature. If you don't want it to scale, don't load the module ;) Dave -- http://www.codemonkey.org.uk