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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 25 May 2023 19:29:21 -0700
Message-ID: <CAHk-=win3ttfr2xb1JcGroPSOoqGs0GooZq0DLsRtZzXUH5YeQ@mail.gmail.com>
Subject: Re: [RFC PATCH v2 2/3] mm: Provide a function to get an additional
 pin on a page
To:     David Howells <dhowells@redhat.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        David Hildenbrand <david@redhat.com>,
        Jens Axboe <axboe@kernel.dk>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>
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On Thu, May 25, 2023 at 3:40=E2=80=AFPM David Howells <dhowells@redhat.com>=
 wrote:
>
> +void page_get_additional_pin(struct page *page)
> +{
> +       struct folio *folio =3D page_folio(page);
> +
> +       if (page =3D=3D ZERO_PAGE(0))
> +               return;

You added that nice "is_zero_folio()", and then you did the above anyway..

               Linus