Linux 2.6.39-rc3

[Ingo Molnar]

* Joerg Roedel <joro at 8bytes.org> wrote:

> On Wed, Apr 13, 2011 at 07:33:40PM -0700, Linus Torvalds wrote:
> >  we definitely want to also understand the reason for things not
> > working, even if we do revert..
> 
> Okay, here it is.
> 
> After experimenting with different configurations for the north-bridge
> it turned out that a GART related MCE fires at the time the machine
> reboots. BIOSes configure the machine to sync-flood in that case which
> causes a reboot.
> 
> After decoding the MCE it turned out to be a GART TBL Wlk Error. Such
> errors can happen if devices (speculativly) access GART ranges mapped
> invalid. The AMD BKDG for Fam10h CPUs recommends to disable these errors
> at all. But unfortunatly some BIOSes (including the one on my laptop)
> forget to do this.
> 
> Below is a patch which disables these errors if the BIOS didn't do it.
> It fixes the problem on my site.

Ok, but how did the allocation changes start triggering this error in 
v2.6.39-rc1? There must still be some layout specific thing here, right?
Do we understand the details of that as well?

Thanks,

	Ingo