From: Nathan Chancellor <natechancellor@gmail.com>
To: ndesaulniers@google.com
Cc: yamada.masahiro@socionext.com, Rui Ueyama <ruiu@google.com>,
Michal Marek <michal.lkml@markovi.net>,
linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] Makefile: lld: set -O2 linker flag when linking with LLD
Date: Thu, 7 Feb 2019 23:07:37 -0700 [thread overview]
Message-ID: <20190208060737.GA12027@archlinux-ryzen> (raw)
In-Reply-To: <20190207220155.81351-4-ndesaulniers@google.com>
On Thu, Feb 07, 2019 at 02:01:52PM -0800, ndesaulniers@google.com wrote:
> -O2 enables tail merging of string table strings.
>
> For arm64:
> 0.34% size improvement with lld -O2 over lld for vmlinux.
> 3.30% size improvement with lld -O2 over lld for Image.lz4-dtb.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/343
> Suggested-by: Rui Ueyama <ruiu@google.com>
> Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> Makefile | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index 6307c17259ea..c07208ec49d4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -718,6 +718,10 @@ else
> KBUILD_CFLAGS += -Wno-unused-but-set-variable
> endif
>
> +ifdef CONFIG_LD_IS_LLD
> +KBUILD_LDFLAGS += -O2
> +endif
> +
> KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
> ifdef CONFIG_FRAME_POINTER
> KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
> --
> 2.20.1.791.gb4d0f1c61a-goog
>
next prev parent reply other threads:[~2019-02-08 6:07 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-07 22:01 [PATCH 1/4] init/Kconfig: add config support for detecting linker ndesaulniers
2019-02-07 22:01 ` [PATCH 2/4] Makefile: clang: choose GCC_TOOLCHAIN_DIR not on LD ndesaulniers
2019-02-08 5:45 ` Nathan Chancellor
2019-02-07 22:01 ` [PATCH 3/4] Makefile: lld: tell clang to use lld ndesaulniers
2019-02-08 5:50 ` Nathan Chancellor
2019-02-08 17:27 ` Nick Desaulniers
2019-02-08 17:45 ` Nathan Chancellor
2019-02-11 15:32 ` Masahiro Yamada
2019-02-11 16:05 ` Sedat Dilek
2019-02-11 19:30 ` Nick Desaulniers
2019-02-11 19:27 ` Nick Desaulniers
2019-02-11 19:26 ` Nick Desaulniers
2019-02-07 22:01 ` [PATCH 4/4] Makefile: lld: set -O2 linker flag when linking with LLD ndesaulniers
2019-02-08 6:07 ` Nathan Chancellor [this message]
2019-02-08 0:48 ` [PATCH 1/4] init/Kconfig: add config support for detecting linker Kees Cook
2019-02-08 0:57 ` Mathieu Desnoyers
2019-02-08 5:41 ` Nathan Chancellor
2019-02-11 15:08 ` Masahiro Yamada
2019-02-08 5:14 ` Nathan Chancellor
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=20190208060737.GA12027@archlinux-ryzen \
--to=natechancellor@gmail.com \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=michal.lkml@markovi.net \
--cc=ndesaulniers@google.com \
--cc=ruiu@google.com \
--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).