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Subject: Re: [PATCH] mm: gup: fix comment of __get_user_pages()
To:     Liu Xiang <liuxiang_1999@126.com>, linux-mm@kvack.org
Cc:     linux-kernel@vger.kernel.org
References: <1571838707-4994-1-git-send-email-liuxiang_1999@126.com>
From:   David Hildenbrand <david@redhat.com>
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Organization: Red Hat GmbH
Message-ID: <3247a4c2-de05-418d-9567-b49df4f2cb2c@redhat.com>
Date:   Wed, 23 Oct 2019 16:25:58 +0200
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On 23.10.19 15:51, Liu Xiang wrote:
> Because nr_pages is unsigned long, it can not be negative.
>=20
> Signed-off-by: Liu Xiang <liuxiang_1999@126.com>
> ---
>  mm/gup.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>=20
> diff --git a/mm/gup.c b/mm/gup.c
> index 8f236a3..0236954 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -735,10 +735,10 @@ static int check_vma_flags(struct vm_area_struct *v=
ma, unsigned long gup_flags)
>   * @nonblocking: whether waiting for disk IO or mmap_sem contention
>   *
>   * Returns number of pages pinned. This may be fewer than the number
> - * requested. If nr_pages is 0 or negative, returns 0. If no pages
> - * were pinned, returns -errno. Each page returned must be released
> - * with a put_page() call when it is finished with. vmas will only
> - * remain valid while mmap_sem is held.
> + * requested. If nr_pages is 0, returns 0. If no pages were pinned,
> + * returns -errno. Each page returned must be released with a
> + * put_page() call when it is finished with. vmas will only remain
> + * valid while mmap_sem is held.

Can we fix the "when it is finished with" part right away, too? At least
it sounds wrong to me, but I am not a native speaker.

Simply "Each page returned must be released with put_page()." should be
good enough

Reviewed-by: David Hildenbrand <david@redhat.com>

--=20

Thanks,

David / dhildenb