Re: [PATCH 1/2] Revert "xen: properly account for _PAGE_NUMA during xen pte translations"

[David Vrabel <david.vrabel@citrix.com>]

On 25/03/14 19:03, David Sutton wrote:
> David,
> 
> On Tue, Mar 25, 2014 at 12:13 PM, David Vrabel <david.vrabel@citrix.com
> <mailto:david.vrabel@citrix.com>> wrote:
> 
>     On 25/03/14 15:28, David Sutton wrote:
>     > David,
>     >
>     >> This reverts commit a9c8e4beeeb64c22b84c803747487857fe424b68.
>     >>
>     > Please note: this particular patch also helped to resolve an issue
>     > reported by some of the people using the xen package under Arch Linux,
>     > where they would see stability issues running certain software
>     > (particularly firefox) under dom0 - the software would start crashing
>     > under relatively light usage, with a kernel BUG message.
> 
>     We are aware that Xen PV guests will not work if CONFIG_NUMA_BALANCING
>     is enabled with this revert.  But that patch introduced fundamental
>     breakage to how a guest must read/write non-present page tables entries
>     which caused even worse breakage.
> 
> Understood - I just wanted to make sure that another symptom of the
> issue was known in case it came up - some people read the issue
> description and were confused as they weren't using any PV guests, only
> seeing the specific application crashes under dom0

dom0 is a PV guest so it is affected.

David