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References: <20200510010603.3896-1-changbin.du@gmail.com>
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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Tue, 12 May 2020 15:52:04 +0900
Message-ID: <CAK7LNARH_1nQRExVSCcJ=Twuze5AosG3z2GcA7zwnF6Vi52GWA@mail.gmail.com>
Subject: Re: [PATCH v5] streamline_config.pl: add LMC_KEEP to preserve some kconfigs
To:     Changbin Du <changbin.du@gmail.com>
Cc:     Jonathan Corbet <corbet@lwn.net>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Randy Dunlap <rdunlap@infradead.org>
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On Sun, May 10, 2020 at 10:06 AM Changbin Du <changbin.du@gmail.com> wrote:
>
> Sometimes it is useful to preserve batches of configs when making
> localmodconfig. For example, I usually don't want any usb and fs
> modules to be disabled. Now we can do it by:
>
>  $ make LMC_KEEP="drivers/usb:fs" localmodconfig
>
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
>
> ---
> v4: fix typo.
> v3: rename LOCALMODCONFIG_PRESERVE to shorter LMC_KEEP.
> v2: fix typo in documentation. (Randy Dunlap)
> ---
>  Documentation/admin-guide/README.rst |  8 +++++++-
>  scripts/kconfig/Makefile             |  1 +
>  scripts/kconfig/streamline_config.pl | 21 +++++++++++++++++++++
>  3 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst
> index cc6151fc0845..407aa206bb70 100644
> --- a/Documentation/admin-guide/README.rst
> +++ b/Documentation/admin-guide/README.rst
> @@ -209,10 +209,16 @@ Configuring the kernel
>                             store the lsmod of that machine into a file
>                             and pass it in as a LSMOD parameter.
>
> +                           Also, you can preserve modules in certain folders
> +                           or kconfig files by specifying their paths in
> +                           parameter LMC_KEEP.
> +
>                     target$ lsmod > /tmp/mylsmod
>                     target$ scp /tmp/mylsmod host:/tmp
>
> -                   host$ make LSMOD=/tmp/mylsmod localmodconfig
> +                   host$ make LSMOD=/tmp/mylsmod \
> +                           LMC_KEEP="drivers/usb:drivers/gpu:fs" \
> +                           localmodconfig
>
>                             The above also works when cross compiling.
>
> diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
> index c9d0a4a8efb3..e0abbf5805f5 100644
> --- a/scripts/kconfig/Makefile
> +++ b/scripts/kconfig/Makefile
> @@ -123,6 +123,7 @@ help:
>         @echo  '  gconfig         - Update current config utilising a GTK+ based front-end'
>         @echo  '  oldconfig       - Update current config utilising a provided .config as base'
>         @echo  '  localmodconfig  - Update current config disabling modules not loaded'
> +       @echo  '                    except those preserved by LMC_KEEP environment variable'
>         @echo  '  localyesconfig  - Update current config converting local mods to core'

Just a nitpicking.

I was just about to apply this patch,
then noticed this.

This works for localyesconfig as well as
localmodconfig.

Do you want to add the note to localyesconfig too?


LMC_ is an acronym of LOCAL_MOD_CONFIG_.
Maybe it is OK because
we mostly use localmodconfig,
using localyesconfig is somewhat rare, I guess.


Just a reminder, if you want to send v6
or if you want me to pick this up as-is.

Thanks.


>         @echo  '  defconfig       - New config with default from ARCH supplied defconfig'
>         @echo  '  savedefconfig   - Save current config as ./defconfig (minimal config)'
> diff --git a/scripts/kconfig/streamline_config.pl b/scripts/kconfig/streamline_config.pl
> index e2f8504f5a2d..19857d18d814 100755
> --- a/scripts/kconfig/streamline_config.pl
> +++ b/scripts/kconfig/streamline_config.pl
> @@ -143,6 +143,7 @@ my %depends;
>  my %selects;
>  my %prompts;
>  my %objects;
> +my %config2kfile;
>  my $var;
>  my $iflevel = 0;
>  my @ifdeps;
> @@ -201,6 +202,7 @@ sub read_kconfig {
>         if (/^\s*(menu)?config\s+(\S+)\s*$/) {
>             $state = "NEW";
>             $config = $2;
> +           $config2kfile{"CONFIG_$config"} = $kconfig;
>
>             # Add depends for 'if' nesting
>             for (my $i = 0; $i < $iflevel; $i++) {
> @@ -591,6 +593,20 @@ while ($repeat) {
>  }
>
>  my %setconfigs;
> +my @preserved_kconfigs = split(/:/,$ENV{LMC_KEEP});
> +
> +sub in_preserved_kconfigs {
> +    my $kconfig = $config2kfile{$_[0]};
> +    if (!defined($kconfig)) {
> +        return 0;
> +    }
> +    foreach my $excl (@preserved_kconfigs) {
> +        if($kconfig =~ /^$excl/) {
> +            return 1;
> +        }
> +    }
> +    return 0;
> +}
>
>  # Finally, read the .config file and turn off any module enabled that
>  # we could not find a reason to keep enabled.
> @@ -644,6 +660,11 @@ foreach my $line (@config_file) {
>      }
>
>      if (/^(CONFIG.*)=(m|y)/) {
> +        if (in_preserved_kconfigs($1)) {
> +            dprint "Preserve config $1";
> +            print;
> +            next;
> +        }
>         if (defined($configs{$1})) {
>             if ($localyesconfig) {
>                 $setconfigs{$1} = 'y';
> --
> 2.25.1
>


-- 
Best Regards
Masahiro Yamada