Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210707161614.13001-1-rdunlap@infradead.org>
In-Reply-To: <20210707161614.13001-1-rdunlap@infradead.org>
From:   Yang Shi <shy828301@gmail.com>
Date:   Wed, 7 Jul 2021 10:25:49 -0700
Message-ID: <CAHbLzkrux+MUof_d-6OmuEYJ-V1k4V_3BY45HafjLoN_9TRQ8g@mail.gmail.com>
Subject: Re: [PATCH] mm: try_to_unmap() is now void
To:     Randy Dunlap <rdunlap@infradead.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Hugh Dickins <hughd@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux MM <linux-mm@kvack.org>,
        Greg Ungerer <gerg@linux-m68k.org>,
        linux-m68k@lists.linux-m68k.org, uclinux-dev@uclinux.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Jul 7, 2021 at 9:16 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> Fix the "CONFIG_MMU is not set" case of converting
> try_to_unmap() from bool to void.
> (as seen on m68k/coldfire)
>
> In file included from ../mm/vmscan.c:33:
> ../mm/vmscan.c: In function 'shrink_page_list':
> ../include/linux/rmap.h:294:34: warning: statement with no effect [-Wunused-value]
>   294 | #define try_to_unmap(page, refs) false
>       |                                  ^~~~~
> ../mm/vmscan.c:1508:4: note: in expansion of macro 'try_to_unmap'
>  1508 |    try_to_unmap(page, flags);
>       |    ^~~~~~~~~~~~
>

Thanks for the patch. hch sent a similar patch
(https://lore.kernel.org/linux-mm/20210705053944.885828-1-hch@lst.de/)
and it has been in -mm tree.

> Fixes: 1fb08ac63bee ("mm: rmap: make try_to_unmap() void function")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: Yang Shi <shy828301@gmail.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-mm@kvack.org
> Cc: Greg Ungerer <gerg@linux-m68k.org>
> Cc: linux-m68k@lists.linux-m68k.org
> Cc: uclinux-dev@uclinux.org
> ---
> v2: add linux-mm m.l.
>     add M68K/Coldfire Cc's
>     change to static inline function.
>
>  include/linux/rmap.h |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- linux-next-20210701.orig/include/linux/rmap.h
> +++ linux-next-20210701/include/linux/rmap.h
> @@ -291,7 +291,8 @@ static inline int page_referenced(struct
>         return 0;
>  }
>
> -#define try_to_unmap(page, refs) false
> +static inline void try_to_unmap(struct page *page, enum ttu_flags flags)
> +{}
>
>  static inline int page_mkclean(struct page *page)
>  {