From: Arnd Bergmann <arnd@arndb.de>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-arch <linux-arch@vger.kernel.org>,
linux-s390 <linux-s390@vger.kernel.org>,
Dave Hansen <dave@sr71.net>,
Michael Ellerman <mpe@ellerman.id.au>,
"the arch/x86 maintainers" <x86@kernel.org>,
linux-mips@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Paul Burton <paul.burton@mips.com>,
Ingo Molnar <mingo@redhat.com>,
linux-mtd <linux-mtd@lists.infradead.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Date: Wed, 20 Mar 2019 10:41:43 +0100 [thread overview]
Message-ID: <CAK8P3a3BG_mxYxxCx4S_+ZKAer_+5FpmkzLk0VrACZekuD=2GQ@mail.gmail.com> (raw)
In-Reply-To: <1553062828-27798-1-git-send-email-yamada.masahiro@socionext.com>
On Wed, Mar 20, 2019 at 7:21 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
>
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
>
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
>
> I tested this patch on my arm/arm64 boards.
>
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
>
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
>
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
>
> This also slightly improves the "Kernel hacking" Kconfig menu.
> Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
> mentioned this config option would be a good fit in the "compiler option"
> menu. I did so.
I think this is a good idea in general, but it is likely to cause a lot of
new warnings. Especially the -Wmaybe-uninitialized warnings get
new false positives every time we get substantially different inlining
decisions.
I've added your patch to my randconfig test setup and will let you
know if I see anything noticeable. I'm currently testing clang-arm32,
clang-arm64 and gcc-x86.
Arnd
next prev parent reply other threads:[~2019-03-20 9:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-20 6:20 [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING Masahiro Yamada
2019-03-20 6:40 ` Masahiro Yamada
2019-03-20 9:38 ` Arnd Bergmann
2019-03-20 10:18 ` Masahiro Yamada
2019-03-20 13:04 ` Arnd Bergmann
2019-03-25 6:04 ` Masahiro Yamada
2019-03-20 9:41 ` Arnd Bergmann [this message]
2019-03-20 13:34 ` Arnd Bergmann
2019-03-23 8:26 ` LEROY Christophe
2019-03-25 6:44 ` Masahiro Yamada
2019-03-26 6:02 ` Christophe Leroy
2019-04-23 3:26 ` Masahiro Yamada
2019-03-25 6:10 ` Masahiro Yamada
2019-03-25 6:12 ` Masahiro Yamada
2019-03-25 7:32 ` Arnd Bergmann
2019-03-25 7:54 ` Masahiro Yamada
2019-03-25 10:25 ` Arnd Bergmann
2019-03-25 10:27 ` Arnd Bergmann
2019-03-21 8:01 ` Heiko Carstens
2019-03-25 6:41 ` Masahiro Yamada
2019-03-23 8:37 ` LEROY Christophe
2019-04-18 13:20 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAK8P3a3BG_mxYxxCx4S_+ZKAer_+5FpmkzLk0VrACZekuD=2GQ@mail.gmail.com' \
--to=arnd@arndb.de \
--cc=akpm@linux-foundation.org \
--cc=dave@sr71.net \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-s390@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mingo@redhat.com \
--cc=mpe@ellerman.id.au \
--cc=paul.burton@mips.com \
--cc=x86@kernel.org \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).