include/linux/khugepaged.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_KHUGEPAGED_H
   3 #define _LINUX_KHUGEPAGED_H
   4
   5 #include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */
   6
   7
   8 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
   9 extern struct attribute_group khugepaged_attr_group;
  10
  11 extern int khugepaged_init(void);
  12 extern void khugepaged_destroy(void);
  13 extern int start_stop_khugepaged(void);
  14 extern int __khugepaged_enter(struct mm_struct *mm);
  15 extern void __khugepaged_exit(struct mm_struct *mm);
  16 extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
  17                                       unsigned long vm_flags);
  18 #ifdef CONFIG_SHMEM
  19 extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr);
  20 #else
  21 static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
  22                                            unsigned long addr)
  23 {
  24 }
  25 #endif
  26
  27 #define khugepaged_enabled()                                           \
  28         (transparent_hugepage_flags &                                  \
  29          ((1<<TRANSPARENT_HUGEPAGE_FLAG) |                     \
  30           (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
  31 #define khugepaged_always()                             \
  32         (transparent_hugepage_flags &                   \
  33          (1<<TRANSPARENT_HUGEPAGE_FLAG))
  34 #define khugepaged_req_madv()                                   \
  35         (transparent_hugepage_flags &                           \
  36          (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
  37 #define khugepaged_defrag()                                     \
  38         (transparent_hugepage_flags &                           \
  39          (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
  40
  41 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
  42 {
  43         if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
  44                 return __khugepaged_enter(mm);
  45         return 0;
  46 }
  47
  48 static inline void khugepaged_exit(struct mm_struct *mm)
  49 {
  50         if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
  51                 __khugepaged_exit(mm);
  52 }
  53
  54 static inline int khugepaged_enter(struct vm_area_struct *vma,
  55                                    unsigned long vm_flags)
  56 {
  57         if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
  58                 if ((khugepaged_always() ||
  59                      (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
  60                     !(vm_flags & VM_NOHUGEPAGE) &&
  61                     !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
  62                         if (__khugepaged_enter(vma->vm_mm))
  63                                 return -ENOMEM;
  64         return 0;
  65 }
  66 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  67 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
  68 {
  69         return 0;
  70 }
  71 static inline void khugepaged_exit(struct mm_struct *mm)
  72 {
  73 }
  74 static inline int khugepaged_enter(struct vm_area_struct *vma,
  75                                    unsigned long vm_flags)
  76 {
  77         return 0;
  78 }
  79 static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
  80                                              unsigned long vm_flags)
  81 {
  82         return 0;
  83 }
  84 static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
  85                                            unsigned long addr)
  86 {
  87 }
  88 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  89
  90 #endif /* _LINUX_KHUGEPAGED_H */