From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756517Ab1KUUDN (ORCPT ); Mon, 21 Nov 2011 15:03:13 -0500 Received: from e38.co.us.ibm.com ([32.97.110.159]:59337 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754492Ab1KUUDH (ORCPT ); Mon, 21 Nov 2011 15:03:07 -0500 Message-ID: <1321905728.6445.2.camel@work-vm> Subject: Re: CPU hyperthreading turned on after soft power-cycle From: John Stultz To: Jiri Polach Cc: Jiri Polach , 647095@bugs.debian.org, Jonathan Nieder , Ben Hutchings , LKML , x86@kernel.org Date: Mon, 21 Nov 2011 12:02:08 -0800 In-Reply-To: <4ECA51B9.3010707@seznam.cz> 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> <4ECA51B9.3010707@seznam.cz> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.1- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 x-cbid: 11112120-5518-0000-0000-00000087A5F1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-11-21 at 14:27 +0100, Jiri Polach wrote: > >>>> 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 ... Good point. I forgot on x86_64 you can't disable HPET_TIMER. Could you then use the following patch (and run make oldconfig before building). thanks -john diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index cb9a104..77b5273 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -640,7 +640,7 @@ config HPET_TIMER Choose N to continue using the legacy 8254 timer. config HPET_EMULATE_RTC - def_bool y + def_bool n depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) config APB_TIMER