On Thu, 18 Jan 2007, Andi Kleen wrote:
The Northbridge guarantees coherency over the aperture, but only if the caching attributes match.
That's interesting. Makes sense, I suppose.
You would need to change_page_attr() every kernel address that is mapped into the IOMMU to use an uncached aperture. AGP does this, but the frequency of mapping for the IOMMU is much higher and it would be prohibitively costly unfortunately.
But it still might be a reasonable thing to do to test the theory that the problem is cache coherency across the graphics aperture, even if it isn't a long-term solution for the problem.
In the past we saw corruptions from such conflicts, so this is more than just theory. I suspect you traded a more easy to trigger corruption with a more subtle one.
Yup. That was the inspiration for the script. Chip -- Charles M. "Chip" Coldwell Senior Software Engineer Red Hat, Inc 978-392-2426 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
