From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754010Ab1KUN12 (ORCPT ); Mon, 21 Nov 2011 08:27:28 -0500 Received: from marge.uochb.cas.cz ([147.231.129.3]:52882 "EHLO marge.uochb.cas.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752851Ab1KUN11 (ORCPT ); Mon, 21 Nov 2011 08:27:27 -0500 Message-ID: <4ECA51B9.3010707@seznam.cz> Date: Mon, 21 Nov 2011 14:27:21 +0100 From: Jiri Polach User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: John Stultz CC: Jiri Polach , 647095@bugs.debian.org, Jonathan Nieder , Ben Hutchings , LKML , x86@kernel.org Subject: Re: CPU hyperthreading turned on after soft power-cycle References: <20111030110543.5872.61279.reportbug@supermicro.uochb.cas.cz> <1319988329.6759.88.camel@deadeye> <4EAE9D3A.7000108@atlas.cz> <4EB92181.5030500@seznam.cz> <20111110015212.GB2399@elie.gateway.2wire.net> <4EBD2825.6050806@atlas.cz> <4EC43DF7.4010902@atlas.cz> <1321561946.25715.16.camel@work-vm> <4EC59BCE.6050902@atlas.cz> <1321574019.25715.52.camel@work-vm> In-Reply-To: <1321574019.25715.52.camel@work-vm> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>> Finally! After another 50+ compilations a have it! It took some time as >>>> first I had to find a reason why some revisions did not boot (almost 2/3 >>>> were unbootable and the first bad commit was among them). Having this >>>> solved I have been able to bisect without "skipping". The result is >>>> surprising (at least for me) - believe it or not, the first bad commit >>>> is 6610e089 "RTC: Rework RTC code to use timerqueue for events" from >>>> John Stultz (I am sending him a copy of this message). >>>> >>>> I would never expect this would be a problem, but my understanding of >>>> this commit is very limited, so I am certainly missing the point. >>>> However, I have tried to compile 2.6.38 (which was "bad") with "Real >>>> Time Clock" configuration option turned off and it behaves "normally" >>>> then (= is "good"). >>> >>> Huh. That's *very* odd. Is your system doing anything in-particular >>> with the RTC? I don't have a clue right off, so probably the next step >> >> Yes, it is very odd. The system does not do anything special with RTC. >> It is a diskless computational workstation. >> >>> is doing a bit of instrumentation to try to figure out where exactly we >>> trigger the behavior. Could you checkout commit 6610e089 and apply the >>> patch below to see if we can't narrow it down? >> >> With the patch applied the system does not show the strange behavior (= >> is "good"). >> >>> Could you also send your .config to me? >> >> Sure. It is attached. I have found that if I turn CONFIG_RTC_DRV_CMOS >> off, the system behaves normally (= is "good") too. > > Yea. My rough guess is that the BIOS is somehow sensitive to how the > CMOS RTC is touched. > > Does disabling CONFIG_HPET_EMULATE_RTC change the behavior? But how do I do it? :-) I have not found a way to disable it in "menuconfig". If I comment it out manually in .config, it is automatically set back to "y" as soon as compilation starts ... Thanks, Jiri