[PATCH 0/1] [Hardy] SRU: Disable 4MB page tables for Atom, work around errata AAE44

[Stefan Bader]

Andy Whitcroft wrote:
> On Fri, Feb 19, 2010 at 03:16:34PM +0000, Colin King wrote:
>> From: Colin Ian King <colin.king at canonical.com>
>>
>> BugLink: https://bugs.launchpad.net/bugs/523112
>>
>> SRU Justification:
>>
>> Impact: Without this patch Intel(R) Atom (TM) CPUs can sometimes
>> seemingly randomly get oopses on legitimate executable pages.
>> This only occurs when splitting large 4MB pages into 4MB pages
>> so this patch disables 4MB pages for this class of processor.
>>
>> Fix: Detect processor type 0x1C and disable 4MB pages.
> 
> Do we understand why this is not exhibiting on later kernels, ie. why is
> this patch only required on Hardy?
> 
> -apw
> 

Not me, frankly. There has been more locking and safeguarding against other
threads in the rewritten mm code. So it is well possible that this works around
the problem in a way I don't understand.

-Stefan