2023-06-19 23:14:11

by Peter Xu

Subject: [PATCH v2 4/8] mm/gup: Cleanup next_page handling

The only path that doesn't use generic "**pages" handling is the gate vma.
Make it use the same path, meanwhile tune the next_page label upper to
cover "**pages" handling. This prepares for THP handling for "**pages".

Reviewed-by: Lorenzo Stoakes <[email protected]>
Signed-off-by: Peter Xu <[email protected]>
---
mm/gup.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 9fc9271cba8d..4a00d609033e 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1124,7 +1124,7 @@ static long __get_user_pages(struct mm_struct *mm,
if (!vma && in_gate_area(mm, start)) {
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, &vma,
- pages ? &pages[i] : NULL);
+ pages ? &page : NULL);
if (ret)
goto out;
ctx.page_mask = 0;
@@ -1194,19 +1194,18 @@ static long __get_user_pages(struct mm_struct *mm,
ret = PTR_ERR(page);
goto out;
}
-
- goto next_page;
} else if (IS_ERR(page)) {
ret = PTR_ERR(page);
goto out;
}
+next_page:
if (pages) {
pages[i] = page;
flush_anon_page(vma, page, start);
flush_dcache_page(page);
ctx.page_mask = 0;
}
-next_page:
+
page_increm = 1 + (~(start >> PAGE_SHIFT) & ctx.page_mask);
if (page_increm > nr_pages)
page_increm = nr_pages;
--
2.40.1

2023-06-20 15:59:23

by David Hildenbrand

Subject: Re: [PATCH v2 4/8] mm/gup: Cleanup next_page handling

On 20.06.23 01:10, Peter Xu wrote:
> The only path that doesn't use generic "**pages" handling is the gate vma.
> Make it use the same path, meanwhile tune the next_page label upper to
> cover "**pages" handling. This prepares for THP handling for "**pages".
>
> Reviewed-by: Lorenzo Stoakes <[email protected]>
> Signed-off-by: Peter Xu <[email protected]>
> ---
> mm/gup.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 9fc9271cba8d..4a00d609033e 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1124,7 +1124,7 @@ static long __get_user_pages(struct mm_struct *mm,
> if (!vma && in_gate_area(mm, start)) {
> ret = get_gate_page(mm, start & PAGE_MASK,
> gup_flags, &vma,
> - pages ? &pages[i] : NULL);
> + pages ? &page : NULL);
> if (ret)
> goto out;
> ctx.page_mask = 0;
> @@ -1194,19 +1194,18 @@ static long __get_user_pages(struct mm_struct *mm,
> ret = PTR_ERR(page);
> goto out;
> }
> -
> - goto next_page;
> } else if (IS_ERR(page)) {
> ret = PTR_ERR(page);
> goto out;
> }
> +next_page:
> if (pages) {
> pages[i] = page;
> flush_anon_page(vma, page, start);
> flush_dcache_page(page);
> ctx.page_mask = 0;
> }
> -next_page:
> +
> page_increm = 1 + (~(start >> PAGE_SHIFT) & ctx.page_mask);
> if (page_increm > nr_pages)
> page_increm = nr_pages;

Acked-by: David Hildenbrand <[email protected]>

--
Cheers,

David / dhildenb