3 files changed, 68 insertions, 0 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index d9ab70d776e2..43a694ef8904 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -25,6 +25,7 @@ enum transparent_hugepage_flag {
 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
 	TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
+	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
 #ifdef CONFIG_DEBUG_VM
 	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
 #endif
diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
new file mode 100644
index 000000000000..552f3184756c
--- /dev/null
+++ b/include/linux/khugepaged.h
@@ -0,0 +1,66 @@
+#ifndef _LINUX_KHUGEPAGED_H
+#define _LINUX_KHUGEPAGED_H
+
+#include <linux/sched.h> /* MMF_VM_HUGEPAGE */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern int __khugepaged_enter(struct mm_struct *mm);
+extern void __khugepaged_exit(struct mm_struct *mm);
+extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma);
+
+#define khugepaged_enabled()					       \
+	(transparent_hugepage_flags &				       \
+	 ((1<<TRANSPARENT_HUGEPAGE_FLAG) |		       \
+	  (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
+#define khugepaged_always()				\
+	(transparent_hugepage_flags &			\
+	 (1<<TRANSPARENT_HUGEPAGE_FLAG))
+#define khugepaged_req_madv()					\
+	(transparent_hugepage_flags &				\
+	 (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
+#define khugepaged_defrag()					\
+	(transparent_hugepage_flags &				\
+	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
+
+static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+	if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
+		return __khugepaged_enter(mm);
+	return 0;
+}
+
+static inline void khugepaged_exit(struct mm_struct *mm)
+{
+	if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
+		__khugepaged_exit(mm);
+}
+
+static inline int khugepaged_enter(struct vm_area_struct *vma)
+{
+	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
+		if (khugepaged_always() ||
+		    (khugepaged_req_madv() &&
+		     vma->vm_flags & VM_HUGEPAGE))
+			if (__khugepaged_enter(vma->vm_mm))
+				return -ENOMEM;
+	return 0;
+}
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+	return 0;
+}
+static inline void khugepaged_exit(struct mm_struct *mm)
+{
+}
+static inline int khugepaged_enter(struct vm_area_struct *vma)
+{
+	return 0;
+}
+static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma)
+{
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#endif /* _LINUX_KHUGEPAGED_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f23b5bb6f52e..d747f948b34e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -434,6 +434,7 @@ extern int get_dumpable(struct mm_struct *mm);
 #endif
 					/* leave room for more dump flags */
 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
+#define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
 
 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)