On 4/4/22 22:02, Yang Shi wrote:
> To reuse hugepage_vma_check() for khugepaged_enter() so that we could
> remove some duplicate code. But moving hugepage_vma_check() to
> khugepaged.h needs to include huge_mm.h in it, it seems not optimal to
> bloat khugepaged.h.
>
> And the khugepaged_* functions actually are wrappers for some non-inline
> functions, so it seems the benefits are not too much to keep them inline.
>
> So move the khugepaged_* functions to khugepaged.c, any callers just
> need to include khugepaged.h which is quite small. For example, the
> following patches will call khugepaged_enter() in filemap page fault path
> for regular filesystems to make readonly FS THP collapse more consistent.
> The filemap.c just needs to include khugepaged.h.
This last part is inaccurate in v3?
> Acked-by: Song Liu <song@xxxxxxxxxx>
> Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
I think moving the tiny wrappers is unnecessary.
How about just making hugepage_vma_check() not static and declare it in
khugepaged.h, then it can be used from khugepaged_enter() in the same file
and AFAICS no need to include huge_mm.h there?
> ---
> include/linux/khugepaged.h | 37 ++++++-------------------------------
> mm/khugepaged.c | 20 ++++++++++++++++++++
> 2 files changed, 26 insertions(+), 31 deletions(-)
>
> diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
> index 0423d3619f26..6acf9701151e 100644
> --- a/include/linux/khugepaged.h
> +++ b/include/linux/khugepaged.h
> @@ -2,10 +2,6 @@
> #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;
>
> @@ -16,6 +12,12 @@ 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_fork(struct mm_struct *mm,
> + struct mm_struct *oldmm);
> +extern void khugepaged_exit(struct mm_struct *mm);
> +extern void khugepaged_enter(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);
> @@ -33,36 +35,9 @@ static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
> #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)
> {
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index b69eda934d70..ec5b0a691d87 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -556,6 +556,26 @@ void __khugepaged_exit(struct mm_struct *mm)
> }
> }
>
> +void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
> +{
> + if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))
> + __khugepaged_enter(mm);
> +}
> +
> +void khugepaged_exit(struct mm_struct *mm)
> +{
> + if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
> + __khugepaged_exit(mm);
> +}
> +
> +void khugepaged_enter(struct vm_area_struct *vma, unsigned long vm_flags)
> +{
> + if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
> + khugepaged_enabled())
> + if (hugepage_vma_check(vma, vm_flags))
> + __khugepaged_enter(vma->vm_mm);
> +}
> +
> static void release_pte_page(struct page *page)
> {
> mod_node_page_state(page_pgdat(page),
