linux-kernel - Re: [PATCH 2/3] modpost: .meminit.* is not in init section when CONFIG_MEMORY

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Message-ID: <CAK7LNAR08Nx3-8XYe4qmUegDFo2zLUvkVdA1t51g1Bamh5Tteg@mail.gmail.com>
Date: Wed, 3 Jul 2024 23:44:38 +0900
From: Masahiro Yamada <masahiroy@...nel.org>
To: Wei Yang <richard.weiyang@...il.com>
Cc: akpm@...ux-foundation.org, nathan@...nel.org, nicolas@...sle.eu, 
	linux-mm@...ck.org, linux-kernel@...r.kernel.org, 
	linux-kbuild@...r.kernel.org, Mike Rapoport <rppt@...nel.org>
Subject: Re: [PATCH 2/3] modpost: .meminit.* is not in init section when
 CONFIG_MEMORY_HOTPLUG set

On Wed, Jul 3, 2024 at 8:40 AM Wei Yang <richard.weiyang@...il.com> wrote:
>
> .meminit.* is not put into init section when CONFIG_MEMORY_HOTPLUG is
> set, since we define MEM_KEEP()/MEM_DISCARD() according to
> CONFIG_MEMORY_HOTPLUG.
>
> Signed-off-by: Wei Yang <richard.weiyang@...il.com>
> CC: Mike Rapoport (IBM) <rppt@...nel.org>
> ---
>  scripts/mod/modpost.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)



NACK.


The section mismatch is performed _unconditionally_.



In the old days, we did this depending on relevant CONFIG options.
It was more than 15 years ago that we stopped doing that.


See this:


commit eb8f689046b857874e964463619f09df06d59fad
Author: Sam Ravnborg <sam@...nborg.org>
Date:   Sun Jan 20 20:07:28 2008 +0100

    Use separate sections for __dev/__cpu/__mem code/data




So, if you wanted to check this only when CONFIG_MEMORY_HOTPLUG=n,
you would need to add #ifdef CONFIG_MEMORY_HOTPLUG to include/linux/init.h

That is what we did in the Linux 2.6.* era, which had much worse
section mismatch coverage.










-- 
Best Regards
Masahiro Yamada