linux-stable/include/linux/khugepaged.h
Yang Shi d2081b2bf8 mm: khugepaged: make khugepaged_enter() void function
The most callers of khugepaged_enter() don't care about the return value. 
Only dup_mmap(), anonymous THP page fault and MADV_HUGEPAGE handle the
error by returning -ENOMEM.  Actually it is not harmful for them to ignore
the error case either.  It also sounds overkilling to fail fork() and page
fault early due to khugepaged_enter() error, and MADV_HUGEPAGE does set
VM_HUGEPAGE flag regardless of the error.

Link: https://lkml.kernel.org/r/20220510203222.24246-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Vlastmil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19 14:08:49 -07:00

91 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KHUGEPAGED_H
#define _LINUX_KHUGEPAGED_H
#include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */
#include <linux/shmem_fs.h>
#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_merge(struct vm_area_struct *vma,
unsigned long vm_flags);
extern void khugepaged_min_free_kbytes_update(void);
#ifdef CONFIG_SHMEM
extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr);
#else
static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
unsigned long addr)
{
}
#endif
#define khugepaged_enabled() \
(transparent_hugepage_flags & \
((1<<TRANSPARENT_HUGEPAGE_FLAG) | \
(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
#define khugepaged_always() \
(transparent_hugepage_flags & \
(1<<TRANSPARENT_HUGEPAGE_FLAG))
#define khugepaged_req_madv() \
(transparent_hugepage_flags & \
(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
#define khugepaged_defrag() \
(transparent_hugepage_flags & \
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
{
if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
__khugepaged_enter(mm);
}
static inline void khugepaged_exit(struct mm_struct *mm)
{
if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
__khugepaged_exit(mm);
}
static inline void khugepaged_enter(struct vm_area_struct *vma,
unsigned long vm_flags)
{
if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
if ((khugepaged_always() ||
(shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) ||
(khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
!(vm_flags & VM_NOHUGEPAGE) &&
!test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
__khugepaged_enter(vma->vm_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(struct vm_area_struct *vma,
unsigned long vm_flags)
{
}
static inline void khugepaged_enter_vma_merge(struct vm_area_struct *vma,
unsigned long vm_flags)
{
}
static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
unsigned long addr)
{
}
static inline void khugepaged_min_free_kbytes_update(void)
{
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* _LINUX_KHUGEPAGED_H */