On Tue, Apr 08, 2014 at 07:30:31PM +0200, Peter Zijlstra wrote: > 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() ? Peter, I somehow missing, with this patch would it be possible to get rid of ugly macros in 2 level pages like we have now? (I've dropped off softdirty support for non x86-64 now [patches are flying around]) but still there are a few remains which make Linus unhappy. static __always_inline pgoff_t pte_to_pgoff(pte_t pte) { return (pgoff_t) (pte_bitop(pte.pte_low, PTE_FILE_SHIFT1, PTE_FILE_MASK1, 0) + pte_bitop(pte.pte_low, PTE_FILE_SHIFT2, PTE_FILE_MASK2, PTE_FILE_LSHIFT2) + pte_bitop(pte.pte_low, PTE_FILE_SHIFT3, -1UL, PTE_FILE_LSHIFT3)); } -- 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>