From d10e63f29488b0f312a443f9507ea9b6fd3c9090 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 25 Oct 2012 14:16:31 +0200 Subject: mm: numa: Create basic numa page hinting infrastructure Note: This patch started as "mm/mpol: Create special PROT_NONE infrastructure" and preserves the basic idea but steals *very* heavily from "autonuma: numa hinting page faults entry points" for the actual fault handlers without the migration parts. The end result is barely recognisable as either patch so all Signed-off and Reviewed-bys are dropped. If Peter, Ingo and Andrea are ok with this version, I will re-add the signed-offs-by to reflect the history. In order to facilitate a lazy -- fault driven -- migration of pages, create a special transient PAGE_NUMA variant, we can then use the 'spurious' protection faults to drive our migrations from. The meaning of PAGE_NUMA depends on the architecture but on x86 it is effectively PROT_NONE. Actual PROT_NONE mappings will not generate these NUMA faults for the reason that the page fault code checks the permission on the VMA (and will throw a segmentation fault on actual PROT_NONE mappings), before it ever calls handle_mm_fault. [dhillf@gmail.com: Fix typo] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel --- include/linux/huge_mm.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux/huge_mm.h') diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index b31cb7d..a1d26a9 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -159,6 +159,10 @@ static inline struct page *compound_trans_head(struct page *page) } return page; } + +extern int do_huge_pmd_numa_page(struct mm_struct *mm, unsigned long addr, + pmd_t pmd, pmd_t *pmdp); + #else /* CONFIG_TRANSPARENT_HUGEPAGE */ #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) @@ -195,6 +199,12 @@ static inline int pmd_trans_huge_lock(pmd_t *pmd, { return 0; } + +static inline int do_huge_pmd_numa_page(struct mm_struct *mm, unsigned long addr, + pmd_t pmd, pmd_t *pmdp) +{ +} + #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* _LINUX_HUGE_MM_H */ -- cgit v1.1