Re: [Bug #11035] System hangs on 2.6.26-rc8

[Ingo Molnar]

* Roman Mindalev <lists@xxxxxxxxx> wrote:

> I done bisection.
> Result below:
> 
> 8f46924600e30b140445f5b84abe9b80d2fff5fb is first bad commit
> commit 8f46924600e30b140445f5b84abe9b80d2fff5fb
> Author: Ingo Molnar <mingo@xxxxxxx>
> Date:   Wed Jan 30 13:34:09 2008 +0100
> 
>     x86: enable CONFIG_DEBUG_PAGEALLOC more widely
> 
>     make CONFIG_DEBUG_PAGEALLOC universally available.
> 
>     CONFIG_HIBERNATION and CONFIG_HUGETLBFS was disabling it, for no
>     particular reason.

as far as i can see you see a lockup under certain circumstances, right?

this debug option catches use-after-free and other types of invalid 
memory accesses. When it catches a bug the kernel most likely crashes 
and produces a backlog. Because you are in graphical mode that is not 
visible.

This would possibly be debuggable if you set up netconsole logging to 
another system on a local LAN - see 
Documentation/networking/netconsole.txt.

Vegard - would it be possible to make DEBUG_PAGEALLOC faults single-shot 
and non-fatal, just like kmemcheck does it? That way people would see a 
nice kernel message instead of an immediate crash. That means we'd have 
to find a reliable filter for DEBUG_PAGEALLOC-provoked pagefaults though 
...

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/