Andi Kleen <[EMAIL PROTECTED]> writes: > On Friday 22 June 2007 22:33, Alan Cox wrote: >> You've got mapped live gart pages from the previous kernel. Even if you >> disable the gart before a memset > > It's probably too late then. It could also interfere with other operations. > If anything the GART should be disabled during kexec shutdown. Perhaps we > just > need a suitable suspend function that does that. Eric, any preferences?
Well it would be a shutdown method not a suspend method. The authors of the suspend code thought sharing code with the reboot and the rmmod case didn't make sense. For a normal kexec into another kernel I think this makes sense. >> you may well have the video card using >> gart translations and possibly live IOMMU mappings for devices using it >> via bus mastering - and those will cause you MCE exceptions with a >> corrupt cpu context flag (ie not nicely recoverable). > > We disable those machine checks on K8 because they're not fully reliable. For the kexec on panic not shutting the hardware down if at all possible is the ideal. There I think we need a mode to not touch a chunk of the iommu and reserve it for the kexec on panic kernel (or perhaps just use the swiotlb code if we need bounce buffers at all). Eric - 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/