Re: early exception error

From: david
Date: Wed Dec 31 2008 - 13:10:40 EST


On Wed, 31 Dec 2008, Cyrill Gorcunov wrote:

[david@xxxxxxx - Tue, Dec 30, 2008 at 05:39:29PM -0800]
On Wed, 31 Dec 2008, Andi Kleen wrote:

david@xxxxxxx 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)

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

David Lang
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