On 12/27/17 at 01:25pm, Borislav Petkov wrote: > On Wed, Dec 27, 2017 at 03:44:49PM +0800, Baoquan He wrote: > > > yes, instead of crashing the machine (because GART may be initialized in the > > > 2nd kernel, overlapping the 1st kernel memory, which the 2nd kernel with its > > > fake e820 map sees as unused). > > > > > > I'd say this is an improvement. > > > > I don't get what you said. If 'iommu=off' only specified in 1st kernel, > > kdump kernel will think the memory which GART bar pointed as a hole. > > This is incorrect. I don't see the improvement. > > So he says, this memory is unused. Why is that incorrect?!? 'iommu=off' specified in 1st kernel, that region will be normal memory, there could be important kernel data written into the place. While kdump kernel will take that region as a gart aperture, trying to read data from that region will cause error which Jiri originally tried to fix.
