PROBLEM: 3.0-rc kernels unbootable since -rc3

julie Sullivan
2011-07-06T21:10:19Z

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.

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