Messages in this thread | | | Date | Fri, 11 Jan 2013 09:56:20 -0700 | Subject | Re: [PATCH] iommu: moving initialization earlier | From | Shuah Khan <> |
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On Fri, Jan 11, 2013 at 7:50 AM, Joerg Roedel <joro@8bytes.org> wrote: > On Thu, Jan 10, 2013 at 01:40:17PM -0700, Shuah Khan wrote: >> I am currently debugging IO_PAGE_FAULTS on 3.6.11 (happens on all >> pre-3.7 releases). I root-caused the reason 3.7 works is because in >> 3.7 amd iommu driver moving up the early iommu initialization from >> irq_remap_ops with the irq remapping feature. > > Have you investigated the reason for those IO_PAGE_FAULTS? I guess they > come from the USB controlers and happen between the time the IOMMU is > enabled and the USB controlers are taken over by the Linux kernel from > the BIOS. > > But I don't see why this patch can have any impact on the IO_PAGE_FAULTS > you are seeing.
USB is one of them and SATA is another. I know with my back-port to split dma ops initialization and this patch Alexey sent, the problem goes away on 3.6.11 and I don't see the problem on 3.7. Same system, and two different boots. I will investigate do more investigation into the nature of these faults I am seeing and get back to you.
Thanks, -- Shuah
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