Re: 2.6.17-mm5

[Andy Whitcroft <apw@shadowen.org>]

Andrew Morton wrote:
> On Sun, 02 Jul 2006 16:27:55 -0700
> "Martin J. Bligh" <mbligh@mbligh.org> wrote:
> 
> 
>>Panic on NUMA-Q (mm4 was fine). Presumably some new scheduler patch
>>
>>divide error: 0000 [#1]
>>8K_STACKS SMP 
>>last sysfs file: 
>>Modules linked in:
>>CPU:    1
>>EIP:    0060:[<c0112b6e>]    Not tainted VLI
>>EFLAGS: 00010046   (2.6.17-mm5-autokern1 #1) 
>>EIP is at find_busiest_group+0x1a3/0x47c
>>eax: 00000000   ebx: 00000007   ecx: 00000000   edx: 00000000
>>esi: 00000000   edi: e75ff264   ebp: e7405ec8   esp: e7405e58
>>ds: 007b   es: 007b   ss: 0068
>>Process swapper (pid: 0, ti=e7404000 task=c13f8560 task.ti=e7404000)
>>Stack: e75ff264 00000010 c0119020 00000000 00000000 00000000 00000000 00000000 
>>       ffffffff 00000000 00000000 00000001 00000001 00000001 00000080 00000000 
>>       00000000 00000200 00000020 00000080 00000000 00000000 e75ff260 c1364960 
>>Call Trace:
>> [<c0119020>] vprintk+0x5f/0x213
>> [<c0112efb>] load_balance+0x54/0x1d6
>> [<c011332d>] rebalance_tick+0xc5/0xe3
>> [<c01137a3>] scheduler_tick+0x2cb/0x2d3
>> [<c01215b4>] update_process_times+0x51/0x5d
>> [<c010c224>] smp_apic_timer_interrupt+0x5a/0x61
>> [<c0102d5b>] apic_timer_interrupt+0x1f/0x24
>> [<c01006c0>] default_idle+0x0/0x59
>> [<c01006f1>] default_idle+0x31/0x59
>> [<c0100791>] cpu_idle+0x64/0x79
>>Code: 00 5b 83 f8 1f 89 c6 5f 0f 8e 63 ff ff ff 8b 45 e0 8b 55 e8 01 45 dc 8b 4a 08 89 c2 01 4d d4 c1 e2 07 89 d0 31 d2 89 ce c1 ee 07 <f7> f1 83 7d 9c 00 89 45 e0 74 17 89 45 d8 8b 55 e8 8b 4d a4 8b 
>>EIP: [<c0112b6e>] find_busiest_group+0x1a3/0x47c SS:ESP 0068:e7405e58
> 
> 
> Yes, Andy's reporting that too.  I asked him to identify the file-n-line
> and he ran away on me.

I went away to debug it, but then had to skip out to a BBQ.  Its
definatly the cpu_power on the group being zero.

group->cpu_power ZERO => c3150920

/me gives Ingo's patch a spin.

-apw