Re: early exception error

Cyrill Gorcunov
2008-12-31T18:30:52Z

[david@lang.hm - Wed, Dec 31, 2008 at 11:12:12AM -0800]
> On Wed, 31 Dec 2008, Cyrill Gorcunov wrote:
>
>> [david@lang.hm - Tue, Dec 30, 2008 at 05:39:29PM -0800]
>>> On Wed, 31 Dec 2008, Andi Kleen wrote:
>>>
>>>> david@lang.hm writes:
>>>>>
>>>>> doing a grep through System.map for the address that appears in the
>>>>> error returns nothing
>>>>
>>>> This might be obvious, but you can't grep directly for these addresses
>>>> because System.map contains the starting addresses of functions only
>>>> and normally the reported address is somewhere in the middle of a
>>>> function. So you instead have to look for the highest number lower or equal
>>>> the address from the exception.
>>>
>>> thanks, this was not obvious to me
>>>
>>> the -2 error maps to
>>>
>>> ffffffff8099e4c1 T free_bootmem_node
>>> ffffffff8099e4e5 t alloc_bootmem_core
>>> ffffffff8099e774 t ___alloc_bootmem_nopanic
>>>
>>>
>>> the first error maps to
>>>
>>> ffffffff809c2de4 T free_bootmem_node
>>> ffffffff809c2e08 t alloc_bootmem_core
>>> ffffffff809c3097 t ___alloc_bootmem_nopanic
>>>
>>>
>>> so it looks like this is in alloc_bootmem_core in both cases.
>>>
>>> David Lang
>>>
>>
>> Along with Andi's proposed earlyprintk=vga I think
>> bootmem_debug option could be usefull here too.
>
> adding bootmem_debug creates so much additonal output that the oops
> scrolls off the screen (except the last 'paragraph' of it)
>
> it looks like it's individual items being allocated (trying to scan it as
> it scrolled by)

on the picture you sent me i noticed the message
"Your memory is not aligned you need to rebuild your
kernel with bigger NODEMAP SIZE shift=20" and then
srat code complains about "No NUMA code hash function found"
which looks a bit scary. Btw, could you post this picture
on some public resource so NUMA people could check it?

>
> if that output is needed I will need to setup a serial console to gather
> it (can this be done for the earlyprintk?)

yep, earlyprintk=serial (at least code say it would support it :)

>
> David Lang
>
- Cyrill -