On Thu, May 23, 2013 at 06:07:50PM +0100, Steve Capper wrote:

The huge_pte_alloc, huge_pte_offset and follow_huge_p[mu]d
functions in x86/mm/hugetlbpage.c do not rely on any architecture
specific knowledge other than the fact that pmds and puds can be
treated as huge ptes.

To allow other architectures to use this code (and reduce the need
for code duplication), this patch copies these functions into mm,
replaces the use of pud_large with pud_huge and provides a config
flag to activate them:
CONFIG_ARCH_WANT_GENERAL_HUGETLB

BTW, I think it's worth mentioning that pud_large is inline while
pud_huge is not.

-- 
Catalin