On Wed, May 18, 2022 at 01:18:40PM +0530, Vivek Kumar wrote: > Add check for pte_valid in saveable page after being checked for > the rest. This is required as PTE is removed for pages allocated > with dma_alloc_coherent with DMA_ATTR_NO_KERNEL_MAPPING flag set. > This patch makes sure that these pages are not considered for > snapshot. I don't think we ever remove kernel PTEs for DMA_ATTR_NO_KERNEL_MAPPING. If the allocation did come from highmem they never had one to start with. The logic here looks a bit fishy to me.