Steve, On Mon, Apr 29, 2013 at 03:55:55PM +0100, Steve Capper wrote: > Under x86, multiple puds can be made to reference the same bank of > huge pmds provided that they represent a full PUD_SIZE of shared > huge memory that is aligned to a PUD_SIZE boundary. > > The code to share pmds does not require any architecture specific > knowledge other than the fact that pmds can be indexed, thus can > be beneficial to some other architectures. > > This patch copies the huge pmd sharing (and unsharing) logic from > x86/ to mm/ and introduces a new config option to activate it: > CONFIG_ARCH_WANTS_HUGE_PMD_SHARE. Just wondering whether more of it could be shared. The following look pretty close to what you'd write for arm64: - huge_pte_alloc() - huge_pte_offset() (there is a pud_large macro on x86 which checks for present & huge, we can replace it with just pud_huge in this function as it already checks for present) - follow_huge_pud() - follow_huge_pmd() Of course, arch-specific macros like pud_huge, pmd_huge would have to go in a header file. -- Catalin -- 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>