Am 15.01.2015 um 11:43 schrieb David Vrabel:

On 15/01/15 08:58, Christian Borntraeger wrote:

quoted

ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145)

Change the p2m code to replace ACCESS_ONCE with READ_ONCE.

Acked-by: David Vrabel <redacted>

Thanks

Let me know if you want me to merge this via the Xen tree.

With your Acked-by, I can easily carry this in my tree. We can 
then ensure that this patch is merged before the ACCESS_ONCE is
made stricter - making bisecting easier.

Christian