Re: 3.6.11 AMD-Vi: Completion-Wait loop timed out

From: Jörg Rödel
Date: Tue Jan 22 2013 - 10:16:22 EST


On Tue, Jan 22, 2013 at 09:36:34AM -0500, Boris Ostrovsky wrote:
>
>
> On 01/22/2013 09:13 AM, Udo van den Heuvel wrote:
> >Gigabyte demonstrate that using ESX 5i IOMMU works fine. (with pictures
> >attached).
>
> There are no attachments to your message.
>
> I am not sure that 5i supports IOMMU (but I may well be wrong).

Virtualization use-cases don't change the page-tables for the IOMMU very
often. So there is less need to flush the IO-TLB and IOMMU command
processing is utilized only from time to time.

In Linux however the page-tables change all the time and there is a much
higher load on the IOMMU command buffer which makes it much more likely
to trigger the hardware problem.


Joerg


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/