From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: Linux-rt fails to boot [any release past 3.12.5-rt7] on all of my machines Date: Fri, 7 Feb 2014 16:22:50 +0100 Message-ID: <20140207152250.GC2382@linutronix.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "linux-rt-users@vger.kernel.org" To: jordan Return-path: Received: from www.linutronix.de ([62.245.132.108]:46355 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751831AbaBGPWv convert rfc822-to-8bit (ORCPT ); Fri, 7 Feb 2014 10:22:51 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: * jordan | 2014-02-05 20:54:59 [-0500]: >Hey list, Hi jordan, >I've been meaning to post, but alas, I am working three jobs right now >(just took on more work) and haven't had a whole lot of free time to >investigate my boot problems on linux-rt (-rt9, -rt10, -rt11, -rt13). > >On 3.12.8-rt11 - i was able to get the kernel to boot via reverting tw= o >patches, from the split queue; > >'timer-Raise-softirq-if-there-s-irq_work.patch' >'timers-do-not-raise-softirq-unconditionally.patch' It was reported to the list that timers-do-not-raise-softirq-unconditionally.patch sometimes stalled the machine. The timer-Raise-softirq-if-there-s-irq_work.patch should have fixes one common case and -rt13 should have coverted them all. >(i haven't tried reverting on -rt13, as i haven't had the time to do t= hat). It should work on -rt13 without reverting them. >however, while this was enough to boot - my system was unstable. thus = i >downgraded my kernel back to trusty 3.12.5-rt7 - which works flawlessl= y for >me. Next, I saw the -rt13 release, thinking maybe the boot issue was >finally solved [according to the change log], but no - it fails just a= s >before... I tried to add debug to grub's commandline but in the end, i= t >wasn't really helpful. [the last thing shown is something about PnP an= d >then ACPI]; > >[ 0.255329] pnp: PnP ACPI: found 10 devices >[ 0.255330] ACPI: bus type PNP unregistered > >(which i would normally see anyway.) this looks like a missing event (like timer interrupt or RCU wakeup and "timers-do-not-raise-softi=E2=80=A6" might be a source of this but then= it should be fixed). >I might have some time over the weekend (hopefully), to take a closer = look >- but i thought i would at least notify the list ~ as i saw another u= ser >have the same booting problems and he has the same CPU as i do; AMD >Phenom 965 X4 [not exactly exotic H/W and every RT release has worked >great on my setup, until 3.12.x-rt8. Now, nothing works properly. >[note: vanilla 3.12.x kernels boot just fine]. > >anyway, if anyone has some suggestions - that i could follow up on ove= r the >weekend that would be fantastic. At [0] is my quilt queue containing tags for releases between the working and non-working release. As mentioned before, timers-do-not-raise-softirq-unconditionally.patch will cause stalls which is finally fixed by timer-rt-Always-raise-the-softirq-if-there-s-irq_wor.patch. Looking at my queue between -rt8 and now there is nothing big except fo= r the "raise softirq unconditional" patch. If you decide to bisect the queue to find the offending post -rt8 patch that causes trouble, please note that take these patches | timers-do-not-raise-softirq-unconditionally.patch | timer-Raise-softirq-if-there-s-irq_work.patch | timer-rt-Always-raise-the-softirq-if-there-s-irq_wor.patch should be applied together since the later two are fixes for the former= =2E [0] git://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/rt-devel.git >cheers > >Jordan Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html