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