On Tue, 6 Sep 2022 10:44:01 +0800 Chen Wandun <chenwandun@xxxxxxxxxx> wrote:
> It is no need to walk page table and find pages if faultin_page success
> and __get_user_pages does't care pages at all, so directly handle next
> page.
>
> ...
>
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1198,7 +1198,10 @@ static long __get_user_pages(struct mm_struct *mm,
> PTR_ERR(page) == -EMLINK, locked);
> switch (ret) {
> case 0:
> - goto retry;
> + if (pages)
> + goto retry;
> + else
> + goto next_page;
> case -EBUSY:
> case -EAGAIN:
> ret = 0;
Looks right to me. I redid the changelog somewhat:
: There is no need to walk page tables and find pages if faultin_page)_
: succeeds and __get_user_pages)_ doesn't care about populating the pages[]
: array. So directly go on to handle the next page.
