linux/include/linux/khugepaged.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KHUGEPAGED_H
#define _LINUX_KHUGEPAGED_H

#include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern struct attribute_group khugepaged_attr_group;

extern int khugepaged_init(void);
extern void khugepaged_destroy(void);
extern int start_stop_khugepaged(void);
extern void __khugepaged_enter(struct mm_struct *mm);
extern void __khugepaged_exit(struct mm_struct *mm);
extern void khugepaged_enter_vma(struct vm_area_struct *vma,
				 unsigned long vm_flags);
extern void khugepaged_min_free_kbytes_update(void);
extern bool current_is_khugepaged(void);
#ifdef CONFIG_SHMEM
extern int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
				   bool install_pmd);
#else
static inline int collapse_pte_mapped_thp(struct mm_struct *mm,
					  unsigned long addr, bool install_pmd)
{
	return 0;
}
#endif

static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{ … }

static inline void khugepaged_exit(struct mm_struct *mm)
{ … }
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{
}
static inline void khugepaged_exit(struct mm_struct *mm)
{
}
static inline void khugepaged_enter_vma(struct vm_area_struct *vma,
					unsigned long vm_flags)
{
}
static inline int collapse_pte_mapped_thp(struct mm_struct *mm,
					  unsigned long addr, bool install_pmd)
{
	return 0;
}

static inline void khugepaged_min_free_kbytes_update(void)
{
}

static inline bool current_is_khugepaged(void)
{
	return false;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif /* _LINUX_KHUGEPAGED_H */