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