From owner-freebsd-stable@FreeBSD.ORG Wed Sep 9 07:43:39 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 6D3381065692 for ; Wed, 9 Sep 2009 07:43:39 +0000 (UTC) (envelope-from doconnor@gsoft.com.au) Received: from cain.gsoft.com.au (cain.gsoft.com.au [203.31.81.10]) by mx1.freebsd.org (Postfix) with ESMTP id D00948FC28 for ; Wed, 9 Sep 2009 07:43:38 +0000 (UTC) Received: from inchoate.gsoft.com.au (inchoate.gsoft.com.au [203.31.81.30]) (authenticated bits=0) by cain.gsoft.com.au (8.13.8/8.13.8) with ESMTP id n897hZna016595 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 9 Sep 2009 17:13:36 +0930 (CST) (envelope-from doconnor@gsoft.com.au) From: "Daniel O'Connor" To: Robert Noland Date: Wed, 9 Sep 2009 17:13:31 +0930 User-Agent: KMail/1.9.10 References: <200909082209.37454.doconnor@gsoft.com.au> <200909091020.51049.doconnor@gsoft.com.au> <1252467764.85394.2903.camel@balrog.2hip.net> In-Reply-To: <1252467764.85394.2903.camel@balrog.2hip.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1456758.cC50VXJilF"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200909091713.34162.doconnor@gsoft.com.au> X-Spam-Score: -3.61 () ALL_TRUSTED,AWL,BAYES_00 X-Scanned-By: MIMEDefang 2.63 on 203.31.81.10 Cc: Henrik Friedrichsen , FreeBSD Stable , Ian Smith 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: Wed, 09 Sep 2009 07:43:39 -0000 --nextPart1456758.cC50VXJilF Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Wed, 9 Sep 2009, Robert Noland wrote: > On Wed, 2009-09-09 at 10:20 +0930, Daniel O'Connor wrote: > > On Wed, 9 Sep 2009, Ian Smith wrote: > > > > > 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'? > > > > Hmm, that could work. > > > > It seems odd to me that there is no direct way the BIOS can notify > > the OS it's throttling the CPU though. > > Some BIOS can and do send an ACPI event when the proc gets hot. In > my experience, this was not a good thing though. The BIOS that I > remember dealing with this on would continuously send the alarms, so > while TCC would kick in and throttle the CPU, the event processing > kept it at 100% utilization until it was powered off to cool. I have Ugh! This system seems to stall for a few seconds and then come back, I=20 haven't see any messages about it in dmesg though. > also been able to determine that TCC had kicked in by looking at the > cpu frequency via sysctl and comparing that to the max frequency > reported for the proc. Yeah, although I couldn't run ps when the CPU was stalled so I'm not=20 sure if I'd catch it or not :) > If the BIOS sent the alarm, but throttled the rate it wouldn't have > been so bad. Not that I had any active fan control on that box to do > anything about it really, but TCC might have actually worked if it > wasn't flooding the acpi event processor. Having the BIOS or CPU do it automatically is sensible since it's a time=20 critical task.. Some basic notification would be nice though. It=20 boggles my mind how difficult it is to do such basic things sometimes.. =2D-=20 Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C --nextPart1456758.cC50VXJilF Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.12 (FreeBSD) iD8DBQBKp1ym5ZPcIHs/zowRAktSAJ9cfj1Vp/EKaWBkdImkKr3saykGEgCfaEge wP16fcV66CI++nJXfaPhVHI= =idir -----END PGP SIGNATURE----- --nextPart1456758.cC50VXJilF--