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authorAndrea Arcangeli <aarcange@redhat.com>2011-01-13 15:46:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:42 -0800
commit0af4e98b6b095c74588af04872f83d333c958c32 (patch)
tree56b1965482470219a8cf11b7e7c875ae91bff46e
parentf66055ab6fb9731dbfce320c5202ef4441b5d77f (diff)
downloadop-kernel-dev-0af4e98b6b095c74588af04872f83d333c958c32.zip
op-kernel-dev-0af4e98b6b095c74588af04872f83d333c958c32.tar.gz
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 <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>
-rw-r--r--include/linux/huge_mm.h6
-rw-r--r--mm/huge_memory.c16
-rw-r--r--mm/madvise.c8
3 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 9301824..d9ab70d 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 7635079..620891f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -896,6 +896,22 @@ out:
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 319528b..ecde40a 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) {
@@ -283,6 +288,9 @@ madvise_behavior_valid(int behavior)
case MADV_MERGEABLE:
case MADV_UNMERGEABLE:
#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ case MADV_HUGEPAGE:
+#endif
return 1;
default:
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