From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751607Ab1GGTb2 (ORCPT ); Thu, 7 Jul 2011 15:31:28 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:57216 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750805Ab1GGTb1 (ORCPT ); Thu, 7 Jul 2011 15:31:27 -0400 Date: Thu, 7 Jul 2011 12:31:15 -0700 From: "Paul E. McKenney" To: julie Sullivan Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org, torvalds@linux-foundation.org Subject: Re: PROBLEM: 3.0-rc kernels unbootable since -rc3 Message-ID: <20110707193115.GA5026@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20110706212348.GO6014@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110706212348.GO6014@linux.vnet.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 06, 2011 at 02:23:48PM -0700, Paul E. McKenney wrote: > On Wed, Jul 06, 2011 at 10:10:16PM +0100, julie Sullivan wrote: > > None of my kernels after 3.0-rc3 will boot on my Dell XPS-M1730 > > (x86-64 2-core) test box running > > Ubuntu (Kubuntu) 11.04 (i.e. the first unbootable one was -rc4). > > The machine freezes immediately after selecting the kernel from the > > bootloader menu, leaving > > me with a blank blue screen so I can't give you any log messages. > > > > It bisects to the following commit: > > > > commit a46e0899eec7a3069bcadd45dfba7bf67c6ed016 > > Author: Paul E. McKenney > > Date: Wed Jun 15 15:47:09 2011 -0700 > > > > rcu: use softirq instead of kthreads except when RCU_BOOST=y > > > > This patch #ifdefs RCU kthreads out of the kernel unless RCU_BOOST=y, > > thus eliminating context-switch overhead if RCU priority boosting has > > not been configured. > > > > Signed-off-by: Paul E. McKenney > > > > I've tried cherry-picking onto good/reverting from bad but I don't > > know what to do with the merge > > conflicts, somebody who knows the code/design needs to look really. > > There are more changes than a > > couple of simple #ifdefs. > > Hello, Julie, > > One approach would be to cherry-pick the following commits: > > f8b7fc6b514f34a51875dd48dff70d4d17a54f38 rcu: Move RCU_BOOST #ifdefs to header f > a46e0899eec7a3069bcadd45dfba7bf67c6ed016 rcu: use softirq instead of kthreads ex > 09223371deac67d08ca0b70bd18787920284c967 rcu: Use softirq to address performance > 9a432736904d386cda28b987b38ba14dae960ecc rcu: Simplify curing of load woes > > Another approach would be to move ahead to v3.0-rc4 or later. Ah, OK, I see that you are having this problem with the later -rc releases as well. I have looked at the commit you bisected to, and don't yet see how it is causing the problem, but will continue looking. And I have to ask... Any chance of a serial console or something similar on your system? It would be very good to see any early printf()s. Thanx, Paul > > Let me know if you need any further info. > > > > The config of the bad kernel will follow in next email, while you're > > waiting here's some nice > > environment info from a good kernel bisected nearest to the offending > > commit for you to enjoy > > looking at :-) > > > > ---------- > > ver_linux: > > Linux julie-MXG071 3.0.0-rc2-bisect-8+ #11 SMP Tue Jul 5 20:50:02 BST > > 2011 x86_64 x86_64 x86_64 GNU/Linux > > > > Gnu C 4.5.2 > > Gnu make 3.81 > > binutils 2.21.0.20110327 > > util-linux 2.17.2 > > mount support > > module-init-tools 3.12 > > e2fsprogs 1.41.14 > > pcmciautils 015 > > Linux C Library 2.13 > > Dynamic linker (ldd) 2.13 > > Procps 3.2.8 > > Net-tools 1.60 > > Kbd 1.15 > > Sh-utils 8.5 > > wireless-tools 30 > > Modules Loaded nouveau uvcvideo r852 sm_common videodev > > iwl4965 nand nand_ids dell_wmi sdhci_pci sdhci nand_ecc firewire_ohci > > mtd dell_laptop v4l2_compat_ioctl32 mmc_core firewire_core ttm > > iwl_legacy drm_kms_helper mxm_wmi intel_agp intel_gtt > > > > ------------------ > > cat /proc/cpuinfo: > > processor : 0 > > vendor_id : GenuineIntel > > cpu family : 6 > > model : 23 > > model name : Intel(R) Core(TM)2 Duo CPU T8300 @ 2.40GHz > > stepping : 6 > > cpu MHz : 2401.000 > > cache size : 3072 KB > > physical id : 0 > > siblings : 2 > > core id : 0 > > cpu cores : 2 > > apicid : 0 > > initial apicid : 0 > > fpu : yes > > fpu_exception : yes > > cpuid level : 10 > > wp : yes > > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge > > mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe > > syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl > > aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm > > sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority > > bogomips : 4787.29 > > clflush size : 64 > > cache_alignment : 64 > > address sizes : 36 bits physical, 48 bits virtual > > power management: > > > > processor : 1 > > vendor_id : GenuineIntel > > cpu family : 6 > > model : 23 > > model name : Intel(R) Core(TM)2 Duo CPU T8300 @ 2.40GHz > > stepping : 6 > > cpu MHz : 800.000 > > cache size : 3072 KB > > physical id : 0 > > siblings : 2 > > core id : 1 > > cpu cores : 2 > > apicid : 1 > > initial apicid : 1 > > fpu : yes > > fpu_exception : yes > > cpuid level : 10 > > wp : yes > > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge > > mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe > > syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl > > aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm > > sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority > > bogomips : 4787.46 > > clflush size : 64 > > cache_alignment : 64 > > address sizes : 36 bits physical, 48 bits virtual > > power management: > > > > ------------------ > > cat /proc/modules: > > nouveau 555654 2 - Live 0xffffffffa0124000 > > uvcvideo 56906 0 - Live 0xffffffffa0115000 > > r852 10128 0 - Live 0xffffffffa0058000 > > sm_common 7684 1 r852, Live 0xffffffffa002e000 > > videodev 73451 1 uvcvideo, Live 0xffffffffa0102000 > > iwl4965 155443 0 - Live 0xffffffffa00db000 > > nand 41249 2 r852,sm_common, Live 0xffffffffa006d000 > > nand_ids 5858 1 nand, Live 0xffffffffa0017000 > > dell_wmi 1625 0 - Live 0xffffffffa0010000 > > sdhci_pci 8832 0 - Live 0xffffffffa002a000 > > sdhci 22896 1 sdhci_pci, Live 0xffffffffa0023000 > > nand_ecc 3888 1 nand, Live 0xffffffffa0009000 > > firewire_ohci 26259 0 - Live 0xffffffffa00d3000 > > mtd 28256 2 sm_common,nand, Live 0xffffffffa00c7000 > > dell_laptop 8899 0 - Live 0xffffffffa00c0000 > > v4l2_compat_ioctl32 7213 1 videodev, Live 0xffffffffa00bb000 > > mmc_core 76861 1 sdhci, Live 0xffffffffa009f000 > > firewire_core 51699 1 firewire_ohci, Live 0xffffffffa008b000 > > ttm 58297 1 nouveau, Live 0xffffffffa005d000 > > iwl_legacy 122602 1 iwl4965, Live 0xffffffffa0033000 > > drm_kms_helper 26926 1 nouveau, Live 0xffffffffa001b000 > > mxm_wmi 1695 1 nouveau, Live 0xffffffffa0013000 > > intel_agp 11475 0 - Live 0xffffffffa000c000 > > intel_gtt 14036 1 intel_agp, Live 0xffffffffa0004000