Bad Page dump (help)

[Felipe Balbi]

Hi,

On Thu, Jul 31, 2014 at 08:24:15AM +0200, Gilles Chanteperdrix wrote:
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> On 07/29/2014 09:07 PM, Felipe Balbi wrote:
> > Hi Russell,
> > 
> > I'm bringing up a new board on today's linux-next but I'm having a bunch
> > of bad_page() calls due to _mapcount not being zero (full logs
> > attached). What could cause that ? Any hints on how to debug ? It's as
> > if page_mapcount_reset() wasn't called for the pages which are causing
> > issues.
> 
> FWIW, the same issue appeared on a Cogent CSB637 board (the last board 
> I use not using DT) in between 3.13 and 3.14. I ran a bisect and found 
> that reverting the following commit:
> 
> commit 84f452b1e8fc73ac0e31254c66e3e2260ce5263d
> Author: Santosh Shilimkar <santosh.shilimkar at ti.com>
> Date:   Sun Jun 30 00:28:46 2013 -0400
> 
>     ARM: mm: Remove bootmem code and switch to NO_BOOTMEM
>     
>     Now with dma_mask series merged and max*pfn has consistent meaning on ARM
>     as rest of the arch's thanks to RMK's mega series, lets switch ARM code
>     to NO_BOOTMEM. With NO_BOOTMEM change, now we use memblock allocator to
>     reserve space for crash kernel to have one less dependency with nobootmem
>     allocator wrapper.
>     
>     Tested with both flat memory and sparse (faked) memory models with highmem
>     enabled.

Thanks I'll give this a shot.

> Seemed to make the issue disappear. I later found out that changing the
> kernel options also made the issue disappear.

which kernel options did you change ?

-- 
balbi
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