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Date:   Wed, 2 Oct 2019 09:54:51 +0200
From:   Michal Hocko <mhocko@kernel.org>
To:     Nick Desaulniers <ndesaulniers@google.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Qian Cai <cai@lca.pw>,
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        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH] mm/memcontrol.c: fix another unused function warning
Message-ID: <20191002075451.GG15624@dhcp22.suse.cz>
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 <CAKwvOdn7J6bvF=58UkeXA8LVAMt-g76EDFT+j5EWc0LdsyX_CQ@mail.gmail.com>
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On Tue 01-10-19 09:36:24, Nick Desaulniers wrote:
> On Tue, Oct 1, 2019 at 7:22 AM Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > Removing the mem_cgroup_id_get() stub function introduced a new warning
> > of the same kind when CONFIG_MMU is disabled:
> >
> > mm/memcontrol.c:4929:13: error: unused function 'mem_cgroup_id_get_many' [-Werror,-Wunused-function]
> >
> > Address this using a __maybe_unused annotation.
> >
> > Note: alternatively, this could be moved into an #ifdef block.  Marking it
> 
> Hi Arnd,
> Thank you for the patch!  I would prefer to move the definition to the
> correct set of #ifdef guards rather than __maybe_unused.  Maybe move
> the definition of mem_cgroup_id_get_many() to just before
> __mem_cgroup_clear_mc()?  I find __maybe_unused to be a code smell.

Agreed!
-- 
Michal Hocko
SUSE Labs