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 extern void khugepaged_min_free_kbytes_update(void);
  19 #ifdef CONFIG_SHMEM
  20 extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr);
  21 #else
  22 static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
  23                                            unsigned long addr)
  24 {
  25 }
  26 #endif
  27
  28 #define khugepaged_enabled()                                           \
  29         (transparent_hugepage_flags &                                  \
  30          ((1<<TRANSPARENT_HUGEPAGE_FLAG) |                     \
  31           (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
  32 #define khugepaged_always()                             \
  33         (transparent_hugepage_flags &                   \
  34          (1<<TRANSPARENT_HUGEPAGE_FLAG))
  35 #define khugepaged_req_madv()                                   \
  36         (transparent_hugepage_flags &                           \
  37          (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
  38 #define khugepaged_defrag()                                     \
  39         (transparent_hugepage_flags &                           \
  40          (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
  41
  42 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
  43 {
  44         if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
  45                 return __khugepaged_enter(mm);
  46         return 0;
  47 }
  48
  49 static inline void khugepaged_exit(struct mm_struct *mm)
  50 {
  51         if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
  52                 __khugepaged_exit(mm);
  53 }
  54
  55 static inline int khugepaged_enter(struct vm_area_struct *vma,
  56                                    unsigned long vm_flags)
  57 {
  58         if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
  59                 if ((khugepaged_always() ||
  60                      (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
  61                     !(vm_flags & VM_NOHUGEPAGE) &&
  62                     !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
  63                         if (__khugepaged_enter(vma->vm_mm))
  64                                 return -ENOMEM;
  65         return 0;
  66 }
  67 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  68 static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
  69 {
  70         return 0;
  71 }
  72 static inline void khugepaged_exit(struct mm_struct *mm)
  73 {
  74 }
  75 static inline int khugepaged_enter(struct vm_area_struct *vma,
  76                                    unsigned long vm_flags)
  77 {
  78         return 0;
  79 }
  80 static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
  81                                              unsigned long vm_flags)
  82 {
  83         return 0;
  84 }
  85 static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
  86                                            unsigned long addr)
  87 {
  88 }
  89
  90 static inline void khugepaged_min_free_kbytes_update(void)
  91 {
  92 }
  93 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  94
  95 #endif /* _LINUX_KHUGEPAGED_H */