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thp: madvise(MADV_HUGEPAGE)

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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 <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli
2011-01-13 15:46:55 -08:00
committed by Linus Torvalds
parent f66055ab6f
commit 0af4e98b6b
3 changed files with 30 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/huge_mm.h
View File

@@ -97,6 +97,7 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
#if HPAGE_PMD_ORDER > MAX_ORDER #if HPAGE_PMD_ORDER > MAX_ORDER
#error "hugepages can't be allocated by the buddy allocator" #error "hugepages can't be allocated by the buddy allocator"
#endif #endif
extern int hugepage_madvise(unsigned long *vm_flags);
#else /* CONFIG_TRANSPARENT_HUGEPAGE */ #else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define HPAGE_PMD_SHIFT ({ BUG(); 0; }) #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
#define HPAGE_PMD_MASK ({ BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUG(); 0; })
@@ -113,6 +114,11 @@ static inline int split_huge_page(struct page *page)
do { } while (0) do { } while (0)
#define wait_split_huge_page(__anon_vma, __pmd) \ #define wait_split_huge_page(__anon_vma, __pmd) \
do { } while (0) do { } while (0)
static inline int hugepage_madvise(unsigned long *vm_flags)
{
BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* _LINUX_HUGE_MM_H */ #endif /* _LINUX_HUGE_MM_H */

16
mm/huge_memory.c
View File

@@ -896,6 +896,22 @@ out:
return ret; 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) void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd)
{ {
struct page *page; struct page *page;

8
mm/madvise.c
View File

@@ -71,6 +71,11 @@ static long madvise_behavior(struct vm_area_struct * vma,
if (error) if (error)
goto out; goto out;
break; break;
case MADV_HUGEPAGE:
error = hugepage_madvise(&new_flags);
if (error)
goto out;
break;
} }
if (new_flags == vma->vm_flags) { if (new_flags == vma->vm_flags) {
@@ -282,6 +287,9 @@ madvise_behavior_valid(int behavior)
#ifdef CONFIG_KSM #ifdef CONFIG_KSM
case MADV_MERGEABLE: case MADV_MERGEABLE:
case MADV_UNMERGEABLE: case MADV_UNMERGEABLE:
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
case MADV_HUGEPAGE:
#endif #endif
return 1; return 1;