From owner-freebsd-stable@FreeBSD.ORG Tue Sep 8 18:09:15 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CD284106568B for ; Tue, 8 Sep 2009 18:09:15 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159]) by mx1.freebsd.org (Postfix) with ESMTP id 3A9E18FC16 for ; Tue, 8 Sep 2009 18:09:14 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id n88HscMl042193; Wed, 9 Sep 2009 03:54:38 +1000 (EST) (envelope-from smithi@nimnet.asn.au) Date: Wed, 9 Sep 2009 03:54:38 +1000 (EST) From: Ian Smith To: Henrik Friedrichsen In-Reply-To: Message-ID: <20090909030624.Y89278@sola.nimnet.asn.au> References: <200909082209.37454.doconnor@gsoft.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: FreeBSD Stable Subject: Re: Detecting CPU throttling on over temperature X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Sep 2009 18:09:15 -0000 On Tue, 8 Sep 2009, Henrik Friedrichsen wrote: > I don't know whether there is a more convenient way, but you could > definitely check the current CPU frequency to detect whether it > changed from the previous one or not. There are several ways to this, > depends on the CPU. You can try messing with cpufreq(4). > > On Tue, Sep 8, 2009 at 2:39 PM, Daniel O'Connor wrote: > > Hi, > > I recently discovered a system where the floppy drive cable was > > intermittently fouling the CPU fan - I believe this caused the CPU to > > overheat and then get throttled by the BIOS. > > > > Does anyone know if it is possible to determine if this is the case? ie > > is there a way to be informed if throttling has occurred? Might be easier to hack powerd.c as an existing pretty lightweight way of monitoring CPU freq (to log or signal on detected freq lowered by throttling, say?) even if you don't need/want it to actually vary freq according to load, eg setting idle/busy shift factors to 'never/always'? cheers, Ian