On Tue, Apr 08, 2014 at 05:46:52PM +0100, Mel Gorman wrote: > Someone will ask why automatic NUMA balancing hints do not use "real" > PROT_NONE but as it would need VMA information to do that on all > architectures it would mean that VMA-fixups would be required when marking > PTEs for NUMA hinting faults so would be expensive. Like this: https://lkml.org/lkml/2012/11/13/431 That used the generic PROT_NONE infrastructure and compared, on fault, the page protection bits against the vma->vm_page_prot bits? So the objection to that approach was the vma-> dereference in pte_numa() ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>