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Subject: Re: [PATCH] mm/shuffle: fix section mismatch warning
To:     Arnd Bergmann <arnd@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        David Hildenbrand <david@redhat.com>,
        Wei Yang <richard.weiyang@linux.alibaba.com>,
        Dan Williams <dan.j.williams@intel.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
References: <20210514135952.2928094-1-arnd@kernel.org>
From:   Nathan Chancellor <nathan@kernel.org>
Message-ID: <1904893e-1e7f-b1a4-454c-6999f8ac670a@kernel.org>
Date:   Fri, 14 May 2021 10:48:22 -0700
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On 5/14/2021 6:59 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> clang sometimes decides not to inline shuffle_zone(), but it calls
> a __meminit function. Without the extra __meminit annotation we get
> this warning:
> 
> WARNING: modpost: vmlinux.o(.text+0x2a86d4): Section mismatch in reference from the function shuffle_zone() to the function .meminit.text:__shuffle_zone()
> The function shuffle_zone() references
> the function __meminit __shuffle_zone().
> This is often because shuffle_zone lacks a __meminit
> annotation or the annotation of __shuffle_zone is wrong.
> 
> shuffle_free_memory() did not show the same problem in my tests, but
> it could happen in theory as well, so mark both as __meminit.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>   mm/shuffle.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/shuffle.h b/mm/shuffle.h
> index 71b784f0b7c3..cec62984f7d3 100644
> --- a/mm/shuffle.h
> +++ b/mm/shuffle.h
> @@ -10,7 +10,7 @@
>   DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
>   extern void __shuffle_free_memory(pg_data_t *pgdat);
>   extern bool shuffle_pick_tail(void);
> -static inline void shuffle_free_memory(pg_data_t *pgdat)
> +static inline void __meminit shuffle_free_memory(pg_data_t *pgdat)
>   {
>   	if (!static_branch_unlikely(&page_alloc_shuffle_key))
>   		return;
> @@ -18,7 +18,7 @@ static inline void shuffle_free_memory(pg_data_t *pgdat)
>   }
>   
>   extern void __shuffle_zone(struct zone *z);
> -static inline void shuffle_zone(struct zone *z)
> +static inline void __meminit shuffle_zone(struct zone *z)
>   {
>   	if (!static_branch_unlikely(&page_alloc_shuffle_key))
>   		return;
>