Hello
On Fri, 21 Jun 2019 17:05:10 -0700 Song Liu <songliubraving@xxxxxx> wrote:
> Next patch will add khugepaged support of non-shmem files. This patch
> renames these two functions to reflect the new functionality:
>
> collapse_shmem() => collapse_file()
> khugepaged_scan_shmem() => khugepaged_scan_file()
>
> Acked-by: Rik van Riel <riel@xxxxxxxxxxx>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> ---
> mm/khugepaged.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 0f7419938008..dde8e45552b3 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1287,7 +1287,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
> }
>
> /**
> - * collapse_shmem - collapse small tmpfs/shmem pages into huge one.
> + * collapse_file - collapse small tmpfs/shmem pages into huge one.
> *
> * Basic scheme is simple, details are more complex:
> * - allocate and lock a new huge page;
> @@ -1304,10 +1304,11 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
> * + restore gaps in the page cache;
> * + unlock and free huge page;
> */
> -static void collapse_shmem(struct mm_struct *mm,
> +static void collapse_file(struct vm_area_struct *vma,
> struct address_space *mapping, pgoff_t start,
> struct page **hpage, int node)
> {
> + struct mm_struct *mm = vma->vm_mm;
> gfp_t gfp;
> struct page *new_page;
> struct mem_cgroup *memcg;
> @@ -1563,7 +1564,7 @@ static void collapse_shmem(struct mm_struct *mm,
> /* TODO: tracepoints */
> }
>
> -static void khugepaged_scan_shmem(struct mm_struct *mm,
> +static void khugepaged_scan_file(struct vm_area_struct *vma,
> struct address_space *mapping,
> pgoff_t start, struct page **hpage)
> {
> @@ -1631,14 +1632,14 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
> result = SCAN_EXCEED_NONE_PTE;
> } else {
> node = khugepaged_find_target_node();
> - collapse_shmem(mm, mapping, start, hpage, node);
> + collapse_file(vma, mapping, start, hpage, node);
> }
> }
>
> /* TODO: tracepoints */
> }
> #else
> -static void khugepaged_scan_shmem(struct mm_struct *mm,
> +static void khugepaged_scan_file(struct vm_area_struct *vma,
> struct address_space *mapping,
> pgoff_t start, struct page **hpage)
> {
> @@ -1722,7 +1723,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
> file = get_file(vma->vm_file);
> up_read(&mm->mmap_sem);
> ret = 1;
> - khugepaged_scan_shmem(mm, file->f_mapping,
> + khugepaged_scan_file(vma, file->f_mapping,
> pgoff, hpage);
> fput(file);
Is it a change that should have put some material in the log message?
Is it unlikely for vma to go without mmap_sem held?
> } else {
> --
> 2.17.1
>
Hillf
