From 0af4e98b6b095c74588af04872f83d333c958c32 Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Thu, 13 Jan 2011 15:46:55 -0800 Subject: [PATCH] thp: madvise(MADV_HUGEPAGE) Add madvise MADV_HUGEPAGE to mark regions that are important to be hugepage backed. Return -EINVAL if the vma is not of an anonymous type, or the feature isn't built into the kernel. Never silently return success. Signed-off-by: Andrea Arcangeli Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/huge_mm.h | 6 ++++++ mm/huge_memory.c | 16 ++++++++++++++++ mm/madvise.c | 8 ++++++++ 3 files changed, 30 insertions(+) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 9301824c7491..d9ab70d776e2 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -97,6 +97,7 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd); #if HPAGE_PMD_ORDER > MAX_ORDER #error "hugepages can't be allocated by the buddy allocator" #endif +extern int hugepage_madvise(unsigned long *vm_flags); #else /* CONFIG_TRANSPARENT_HUGEPAGE */ #define HPAGE_PMD_SHIFT ({ BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUG(); 0; }) @@ -113,6 +114,11 @@ static inline int split_huge_page(struct page *page) do { } while (0) #define wait_split_huge_page(__anon_vma, __pmd) \ do { } while (0) +static inline int hugepage_madvise(unsigned long *vm_flags) +{ + BUG(); + return 0; +} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* _LINUX_HUGE_MM_H */ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 763507932898..620891f4e54f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -896,6 +896,22 @@ int split_huge_page(struct page *page) return ret; } +int hugepage_madvise(unsigned long *vm_flags) +{ + /* + * Be somewhat over-protective like KSM for now! + */ + if (*vm_flags & (VM_HUGEPAGE | VM_SHARED | VM_MAYSHARE | + VM_PFNMAP | VM_IO | VM_DONTEXPAND | + VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE | + VM_MIXEDMAP | VM_SAO)) + return -EINVAL; + + *vm_flags |= VM_HUGEPAGE; + + return 0; +} + void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd) { struct page *page; diff --git a/mm/madvise.c b/mm/madvise.c index 319528b8db74..ecde40a401c1 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -71,6 +71,11 @@ static long madvise_behavior(struct vm_area_struct * vma, if (error) goto out; break; + case MADV_HUGEPAGE: + error = hugepage_madvise(&new_flags); + if (error) + goto out; + break; } if (new_flags == vma->vm_flags) { @@ -282,6 +287,9 @@ madvise_behavior_valid(int behavior) #ifdef CONFIG_KSM case MADV_MERGEABLE: case MADV_UNMERGEABLE: +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + case MADV_HUGEPAGE: #endif return 1; -- GitLab