From owner-freebsd-mobile@FreeBSD.ORG Tue Feb 10 16:08:49 2009 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DEAAA106566B for ; Tue, 10 Feb 2009 16:08:49 +0000 (UTC) (envelope-from bengta@P142.sics.se) Received: from sink.sics.se (sink.sics.se [193.10.64.88]) by mx1.freebsd.org (Postfix) with ESMTP id 6DFF28FC1A for ; Tue, 10 Feb 2009 16:08:49 +0000 (UTC) (envelope-from bengta@P142.sics.se) Received: from P142.sics.se (P142.sics.se [193.10.66.253]) by sink.sics.se (8.14.3/8.14.3) with ESMTP id n1AG7ltt015562 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 10 Feb 2009 17:07:49 +0100 (CET) (envelope-from bengta@P142.sics.se) Received: from P142.sics.se (localhost [127.0.0.1]) by P142.sics.se (8.14.3/8.14.3) with ESMTP id n1AG7V8X001283; Tue, 10 Feb 2009 17:07:31 +0100 (CET) (envelope-from bengta@P142.sics.se) Received: (from bengta@localhost) by P142.sics.se (8.14.3/8.14.3/Submit) id n1AG7Mde001281; Tue, 10 Feb 2009 17:07:22 +0100 (CET) (envelope-from bengta@P142.sics.se) To: Ian Smith From: Bengt Ahlgren In-Reply-To: <20090210154047.N38905@sola.nimnet.asn.au> (Ian Smith's message of "Tue\, 10 Feb 2009 16\:13\:23 +1100 \(EST\)") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (berkeley-unix) References: <20090210154047.N38905@sola.nimnet.asn.au> Date: Tue, 10 Feb 2009 17:07:22 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-mobile@freebsd.org Subject: Re: Problems with ath at kern.hz=100 X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Feb 2009 16:08:50 -0000 Ian Smith writes: > On Mon, 9 Feb 2009, Bengt Ahlgren wrote: > > > I was changing kern.hz to 100 on my IBM X40 (Pentium-M) laptop to see > > whether that saves some battery, but ran into problems with ath not > > working properly. At first I thought that my hardware was failing, > > but changing hz back to 1000 solved the problem. I am running > > 7.1-RELEASE-p1 and have the following Atheros chip: > > > > Feb 9 11:13:10 P142 kernel: ath_hal: 0.9.20.3 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413) > > Feb 9 11:13:10 P142 kernel: ath0: mem 0xd0200000-0xd020ffff irq 11 at device 2.0 on pci2 > > Feb 9 11:13:10 P142 kernel: ath0: [ITHREAD] > > Feb 9 11:13:10 P142 kernel: ath0: WARNING: using obsoleted if_watchdog interface > > Feb 9 11:13:10 P142 kernel: ath0: Ethernet address: 00:05:4e:4e:1f:c7 > > Feb 9 11:13:10 P142 kernel: ath0: mac 5.6 phy 4.1 5ghz radio 1.7 2ghz radio 2.3 > > There's an order of magnitude room to move between 100 and 1000 Hz. > You could also try with maybe 250 or 500? I have been running with hz=250 for a while now without the problem occuring. > What speed is your Pentium-M? Are you using powerd? If so, what > minimum CPU freq does it drop back to (sysctl debug.cpufreq.lowest)? It is a 1200MHz. I have debug.cpufreq.lowest=600 in order to only use EST. I ran for a while at 1200MHz with no powerd and ath still stopped sending. > Sam has talked of a problem with ath (and maybe other) interrupt rates > overwhelming slow CPUs to the extent that userland (ie powerd) doesn't > get a look-in for a while, as I understand it. A fast CPU clocked back > to less than say 300MHz IS a slow CPU, until powerd gets to crank it up. > > You might find that rc.conf setting economy_cx_lowest="LOW" can save you > some battery, though this benefit seems somewhat processor-dependent. I tried with dev.cpu.0.cx_lowest=C1 (at 1200MHz), but with no difference - the problem is still there. Bengt