xref: /linux-6.15/include/linux/khugepaged.h (revision bb7e5ce7)
1 #ifndef _LINUX_KHUGEPAGED_H
2 #define _LINUX_KHUGEPAGED_H
3 
4 #include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */
5 
6 
7 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
8 extern struct attribute_group khugepaged_attr_group;
9 
10 extern int khugepaged_init(void);
11 extern void khugepaged_destroy(void);
12 extern int start_stop_khugepaged(void);
13 extern int __khugepaged_enter(struct mm_struct *mm);
14 extern void __khugepaged_exit(struct mm_struct *mm);
15 extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
16 				      unsigned long vm_flags);
17 
18 #define khugepaged_enabled()					       \
19 	(transparent_hugepage_flags &				       \
20 	 ((1<<TRANSPARENT_HUGEPAGE_FLAG) |		       \
21 	  (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
22 #define khugepaged_always()				\
23 	(transparent_hugepage_flags &			\
24 	 (1<<TRANSPARENT_HUGEPAGE_FLAG))
25 #define khugepaged_req_madv()					\
26 	(transparent_hugepage_flags &				\
27 	 (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
28 #define khugepaged_defrag()					\
29 	(transparent_hugepage_flags &				\
30 	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
31 
32 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
33 {
34 	if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
35 		return __khugepaged_enter(mm);
36 	return 0;
37 }
38 
39 static inline void khugepaged_exit(struct mm_struct *mm)
40 {
41 	if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
42 		__khugepaged_exit(mm);
43 }
44 
45 static inline int khugepaged_enter(struct vm_area_struct *vma,
46 				   unsigned long vm_flags)
47 {
48 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
49 		if ((khugepaged_always() ||
50 		     (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
51 		    !(vm_flags & VM_NOHUGEPAGE) &&
52 		    !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
53 			if (__khugepaged_enter(vma->vm_mm))
54 				return -ENOMEM;
55 	return 0;
56 }
57 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
58 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
59 {
60 	return 0;
61 }
62 static inline void khugepaged_exit(struct mm_struct *mm)
63 {
64 }
65 static inline int khugepaged_enter(struct vm_area_struct *vma,
66 				   unsigned long vm_flags)
67 {
68 	return 0;
69 }
70 static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
71 					     unsigned long vm_flags)
72 {
73 	return 0;
74 }
75 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
76 
77 #endif /* _LINUX_KHUGEPAGED_H */
78