On Fri, Nov 11, 2011 at 5:08 PM, Chris Wright <chrisw@xxxxxxxxxxxx> wrote: >> I would be more inclined to suspect that there's some >> chipset buffering that we aren't correctly flushing (which might in >> itself be a hardware issue, since the way to flush the cache is supposed >> to be well-defined). > > Roland, have you tried switching BIOS to Coherency On and can do you > ever see stale PTEs? Yeah, the problems go away if I turn on coherency. More details here: https://lkml.org/lkml/2011/10/11/412 (and after that email, I let the box run long enough that I'm pretty sure turning VT-d coherency on does fix things) I'd love to fix this but not sure how much I can contribute beyond tests (I don't see anything wrong in the VT-d cache flushing code in the kernel, and I did look for a while). - R. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
