Re: PROBLEM: 3.0-rc kernels unbootable since -rc3

Paul E. McKenney
2011-07-07T19:31:28Z

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 <paulmck@linux.vnet.ibm.com>
> > 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 <paulmck@linux.vnet.ibm.com>
> >
> > 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