Hi Bjorn, On Mon, Jul 10, 2017 at 11:53:58AM -0500, Bjorn Helgaas wrote: > I'm still confused. Per Samuel > (6dd9dbac-9b65-bc7c-bb08-413a05d09fc8@xxxxxxxx): > > Samuel> The other patch seems to fix this issue without disabling ATS. > Samuel> Isn't that better? > > and Alex > (BN6PR12MB1652DF4130FC792B71DD9974F7C00@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx): > > Alex> I talked to our validation team and ATS was validated on Stoney, > Alex> so this patch is just working around something else. The other > Alex> patch fixes it and is a valid optimization ... > > I'm confused about what this "other patch" is and whether we want that > one, this one, or both. The other patches floating around lowered the ATS flush-rate from the AMD IOMMU driver, which makes the issue disappear as well. But the issue only disappeared, it is not solved and could probably still be reproduced with a GPU usage pattern that increases the ATS flush-rate. So blacklisting the device for ATS is still the safest thing we could do here. Regards, Joerg
