Re: [PATCH] init: add support for zstd compressed modules

From: Masahiro Yamada <masahiroy@kernel.org>
To: Piotr Gorski <lucjan.lucjanov@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Oleksandr Natalenko <oleksandr@natalenko.name>
Subject: Re: [PATCH] init: add support for zstd compressed modules
Date: Wed, 7 Apr 2021 23:32:56 +0900	[thread overview]
Message-ID: <CAK7LNAToxp4DDAjJfaa9tsP5Fmep7YorfD7ObyEGtJ6_4ioc_A@mail.gmail.com> (raw)
In-Reply-To: <20210330113235.2767216-1-lucjan.lucjanov@gmail.com>

On Tue, Mar 30, 2021 at 8:33 PM Piotr Gorski <lucjan.lucjanov@gmail.com> wrote:
>
> kmod 28 supports modules compressed in zstd format so let's add this possibility to kernel.
>
> Signed-off-by: Piotr Gorski <lucjan.lucjanov@gmail.com>
> ---
>  Makefile     | 7 +++++--
>  init/Kconfig | 9 ++++++---
>  2 files changed, 11 insertions(+), 5 deletions(-)

Piort, sorry for bothering you,
but could you rebase on top of this
clean-up patch set?

https://patchwork.kernel.org/project/linux-kbuild/list/?series=458809

or

git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kbuild

The module compression code should not be placed
in the top Makefile.

> diff --git a/Makefile b/Makefile
> index 5160ff8903c1..82f4f4cc2955 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1156,8 +1156,8 @@ endif # INSTALL_MOD_STRIP
>  export mod_strip_cmd
>
>  # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
> -# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
> -# or CONFIG_MODULE_COMPRESS_XZ.
> +# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP,
> +# CONFIG_MODULE_COMPRESS_XZ, or CONFIG_MODULE_COMPRESS_ZSTD.
>
>  mod_compress_cmd = true
>  ifdef CONFIG_MODULE_COMPRESS
> @@ -1167,6 +1167,9 @@ ifdef CONFIG_MODULE_COMPRESS
>    ifdef CONFIG_MODULE_COMPRESS_XZ
>      mod_compress_cmd = $(XZ) --lzma2=dict=2MiB -f
>    endif # CONFIG_MODULE_COMPRESS_XZ
> +  ifdef CONFIG_MODULE_COMPRESS_ZSTD
> +    mod_compress_cmd = $(ZSTD) -T0 --rm -f -q
> +  endif # CONFIG_MODULE_COMPRESS_ZSTD
>  endif # CONFIG_MODULE_COMPRESS
>  export mod_compress_cmd
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 8c2cfd88f6ef..86a452bc2747 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -2250,8 +2250,8 @@ config MODULE_COMPRESS
>         bool "Compress modules on installation"
>         help
>
> -         Compresses kernel modules when 'make modules_install' is run; gzip or
> -         xz depending on "Compression algorithm" below.
> +         Compresses kernel modules when 'make modules_install' is run; gzip,
> +         xz, or zstd depending on "Compression algorithm" below.
>
>           module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
>
> @@ -2273,7 +2273,7 @@ choice
>           This determines which sort of compression will be used during
>           'make modules_install'.
>
> -         GZIP (default) and XZ are supported.
> +         GZIP (default), XZ, and ZSTD are supported.
>
>  config MODULE_COMPRESS_GZIP
>         bool "GZIP"
> @@ -2281,6 +2281,9 @@ config MODULE_COMPRESS_GZIP
>  config MODULE_COMPRESS_XZ
>         bool "XZ"
>
> +config MODULE_COMPRESS_ZSTD
> +       bool "ZSTD"
> +
>  endchoice
>
>  config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
> --
> 2.31.0.97.g1424303384
>

--
Best Regards
Masahiro Yamada