xref: /linux-6.15/include/linux/khugepaged.h (revision 06236f4e)
1 #ifndef _LINUX_KHUGEPAGED_H
2 #define _LINUX_KHUGEPAGED_H
3 
4 #include <linux/sched.h> /* MMF_VM_HUGEPAGE */
5 
6 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
7 extern struct attribute_group khugepaged_attr_group;
8 
9 extern int khugepaged_init(void);
10 extern void khugepaged_destroy(void);
11 extern int start_stop_khugepaged(void);
12 extern int __khugepaged_enter(struct mm_struct *mm);
13 extern void __khugepaged_exit(struct mm_struct *mm);
14 extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
15 				      unsigned long vm_flags);
16 
17 #define khugepaged_enabled()					       \
18 	(transparent_hugepage_flags &				       \
19 	 ((1<<TRANSPARENT_HUGEPAGE_FLAG) |		       \
20 	  (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
21 #define khugepaged_always()				\
22 	(transparent_hugepage_flags &			\
23 	 (1<<TRANSPARENT_HUGEPAGE_FLAG))
24 #define khugepaged_req_madv()					\
25 	(transparent_hugepage_flags &				\
26 	 (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
27 #define khugepaged_defrag()					\
28 	(transparent_hugepage_flags &				\
29 	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
30 
31 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
32 {
33 	if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
34 		return __khugepaged_enter(mm);
35 	return 0;
36 }
37 
38 static inline void khugepaged_exit(struct mm_struct *mm)
39 {
40 	if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
41 		__khugepaged_exit(mm);
42 }
43 
44 static inline int khugepaged_enter(struct vm_area_struct *vma,
45 				   unsigned long vm_flags)
46 {
47 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
48 		if ((khugepaged_always() ||
49 		     (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
50 		    !(vm_flags & VM_NOHUGEPAGE))
51 			if (__khugepaged_enter(vma->vm_mm))
52 				return -ENOMEM;
53 	return 0;
54 }
55 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
56 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
57 {
58 	return 0;
59 }
60 static inline void khugepaged_exit(struct mm_struct *mm)
61 {
62 }
63 static inline int khugepaged_enter(struct vm_area_struct *vma,
64 				   unsigned long vm_flags)
65 {
66 	return 0;
67 }
68 static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
69 					     unsigned long vm_flags)
70 {
71 	return 0;
72 }
73 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
74 
75 #endif /* _LINUX_KHUGEPAGED_H */
76