Subject: Re: [BUG] 2.6.25-rc2-git4 - Regression Kernel oops while running kernbench and tbench on powerpc

From: Kamalesh Babulal <[email-masked]>
Date: Wed, 09 Apr 2008 10:50:39 +0530

Paul Mackerras wrote:
> Kamalesh Babulal writes:
> 
>> The kernel oops after applying the patch. Some time it takes more than
>> one run to reproduce it, it was reproducible in the second run this
>> time.
>>
>>  Unrecoverable exception 4100 at c000000000008c8c
>> Oops: Unrecoverable exception, sig: 6 [#1]
>> SMP NR_CPUS=128 NUMA pSeries
>> Modules linked in:
>> NIP: c000000000008c8c LR: 000000000ff0135c CTR: 000000000ff012f0
>> REGS: c000000772343bb0 TRAP: 4100   Not tainted  (2.6.25-rc8-autotest)
>> MSR: 8000000000001030 <ME,IR,DR>  CR: 44044228  XER: 00000000
>> TASK = c00000077cfa0900[13437] 'cc1' THREAD: c000000772340000 CPU: 2
>> GPR00: 0000000000004000 c000000772343e30 00000000000000bb 000000000000d032 
>> GPR04: 00000000000000bb 0000000000000400 000000000000000a 0000000000000002 
>> GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
>> GPR12: 0000000000000000 c000000000734000 0000000000000064 00000000ffe6df08 
>> GPR16: 00000000105b0000 00000000105b0000 0000000010440000 00000000105b0000 
>> GPR20: 00000000ffe6e008 00000000105b0000 00000000105b0000 000000000000000a 
>> GPR24: 000000000ffec408 0000000000000001 00000000ffe6ddca 0000000000000400 
>> GPR28: 000000000ffec408 00000000f7ff8000 000000000ffebff4 0000000000000400 
>> NIP [c000000000008c8c] restore+0x8c/0xc0
>> LR [000000000ff0135c] 0xff0135c
>> Call Trace:
>> [c000000772343e30] [c000000000008cd4] do_work+0x14/0x2c (unreliable)
>> Instruction dump:
>> 7c840078 7c810164 70604000 41820028 60000000 7c4c42e6 e88d01f0 f84d01f0 
>> 7c841050 e84d01e8 7c422214 f84d01e8 <e9a100d8> 7c7b03a6 e84101a0 7c4ff120 
> 
> That looks like the bug that was supposed to be fixed by commit
> 44387e9ff25267c78a99229aca55ed750e9174c7, which is in 2.6.25-rc7 and
> later.  
> 
> What was the SHA1 ID of the head commit for the kernel source that
> gave you this oops?  Did you have any other patches besides the one I
> sent you applied?
> 
> Paul.

The SHA1 ID of the kernel is 0e81a8ae37687845f7cdfa2adce14ea6a5f1dd34 (2.6.25-rc8) 
and the source seems to have the patch 44387e9ff25267c78a99229aca55ed750e9174c7.

The kernel was patched only the patch you gave me (http://lkml.org/lkml/2008/4/8/42). 

-- 
Thanks & Regards,
Kamalesh Babulal,
Linux Technology Center,
IBM, ISTL.