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From:   SeongJae Park <sj@kernel.org>
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>, llvm@lists.linux.dev,
        Vineet Gupta <vgupta@kernel.org>,
        Mike Rapoport <rppt@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        "Liam R. Howlett" <Liam.Howlett@Oracle.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Naoya Horiguchi <naoya.horiguchi@nec.com>,
        linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, SeongJae Park <sj@kernel.org>
Subject: Re: [PATCH] [v2] mm: make arch_has_descending_max_zone_pfns() static
Date:   Mon, 17 Apr 2023 18:55:25 +0000
Message-Id: <20230417185525.1420-1-sj@kernel.org>
In-Reply-To: <20230415081904.969049-1-arnd@kernel.org>
References: 
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On Sat, 15 Apr 2023 10:18:20 +0200 Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
> 
> clang produces a build failure on x86 for some randconfig builds
> after a change that moves around code to mm/mm_init.c:
> 
> Cannot find symbol for section 2: .text.
> mm/mm_init.o: failed
> 
> I have not been able to figure out why this happens, but the __weak
> annotation on arch_has_descending_max_zone_pfns() is the trigger here.
> 
> Removing the weak function in favor of an open-coded Kconfig option
> check avoids the problem and becomes clearer as well as better to
> optimize by the compiler.
> 
> Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c")
> Cc: llvm@lists.linux.dev
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> v2: fix logic bug reported-by: kernel test robot <oliver.sang@intel.com>,
> see https://lore.kernel.org/oe-lkp/202304151422.5e4d380b-oliver.sang@intel.com

I was also encountering similar issue, and confirmed replacing the old version
of this patch with this one fixes it.

Tested-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

> ---
>  arch/arc/mm/init.c | 5 -----
>  include/linux/mm.h | 1 -
>  mm/mm_init.c       | 4 ++--
>  3 files changed, 2 insertions(+), 8 deletions(-)