From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: Kernel panic at boot with ondemand governor as default (2.6.24-rc2) Date: Mon, 12 Nov 2007 15:26:29 -0500 Message-ID: <20071112202629.GA31763@redhat.com> References: <4737539F.2070401@lifl.fr> <1194859012.4590.595.camel@queen.suse.de> <47385D05.20705@lifl.fr> <1194880989.5474.12.camel@queen.suse.de> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1194880989.5474.12.camel@queen.suse.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="iso-8859-1" To: Thomas Renninger Cc: Eric Piel , linux-kernel@vger.kernel.org, Venkatesh Pallipadi , cpufreq On Mon, Nov 12, 2007 at 04:23:09PM +0100, Thomas Renninger wrote: > On Mon, 2007-11-12 at 15:02 +0100, Eric Piel wrote: > > 11/12/2007 10:16 AM, Thomas Renninger wrote/a =E9crit: > > > On Sun, 2007-11-11 at 20:10 +0100, Eric Piel wrote: > > >> Hello, > > >> > > >> I've tried kernel 2.6.24-rc2 and I have a problem with the new = option=20 > > >> for setting up the cpufreq ondemand governor as default: a kern= el panic=20 > > >> happens early at boot time. If I boot first with performance go= vernor=20 > > >> and later change to ondemand, everything is fine (as usual). > > >> > > >> This seems related to the delayed_workqueue. The kernel panic m= essage=20 > > >> finishes by: > > >> EIP: [] wq_per_cpu+0x0/0x10 SS:ESP 0068:c191be58 > > >> Kernel panic - not syncing: Attempted to kill init! > > >> > > >> A picture of the whole message is available here: > > >> http://pieleric.free.fr/unorder/1162-ondemand-panic.jpg > > >> > > >> My computer is a x86 using speedstep-ich, and you can find the = full=20 > > >> .config leading to the panic attached. > > >> > > >> Does anyone has any idea was it going wrong? > > >=20 > > > Does it work if you compile speedstep-ich as a module? > > > If you load it, ondemand governor should still be set up automat= ically. > > > If this works, could it be that the kernel does not like that > > > queue_delayed_work_on is called that early? > >=20 > > Yes, it works if I compile speedstep-ich as module. I've put the m= odule=20 > > in initramfs and as soon it is loaded, the ondemand governor is se= lected=20 > > and works. > >=20 > > However, do you think it's ok to prevent cpufreq drivers to be bui= lt-in=20 > > if ondemand governor is selected as default? > > Another way would be to=20 > > reorganise the initialisation code so that workqueue is initialise= d=20 > > before the cpufreq framework is started, do you think it's possibl= e? > Making all this work with low-level drivers built in would be perfec= t of > course... > If nobody answers the next days, could you open a bug at > bugzilla.kernel.org, so that this does not get lost, pls. > Add myself and Venkatesh to CC... > I try to have a look at it ASAP. > If someone already finds out more, this would be great. I'm actually surprised that speedstep-ich works with a low enough latency for ondemand. On the kernel that works, can you boot with cpufreq.debug=3D7 and send the cpufreq messages from dmesg? Dave --=20 http://www.codemonkey.org.uk