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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 3 Dec 2019 11:00:54 +0100
Message-ID: <CAMuHMdXdWASPa3yr04N5w9jTt3=jC_H20yVpcG1J1_Sx0PRtgA@mail.gmail.com>
Subject: Re: [PATCH 1/2] x86_64_defconfig: Normalize x86_64 defconfig
To:     Krzysztof Kozlowski <krzk@kernel.org>
Cc:     Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Collabora Kernel ML <kernel@collabora.com>,
        Guenter Roeck <groeck@chromium.org>,
        Benson Leung <bleung@chromium.org>,
        Dmitry Torokhov <dtor@chromium.org>,
        fabien.lahoudere@collabora.com,
        Guillaume Tucker <guillaume.tucker@collabora.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "Ahmed S. Darwish" <darwish.07@gmail.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Alexey Brodkin <alexey.brodkin@synopsys.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ard Biesheuvel <ardb@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>
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Hi Krzysztof,

On Tue, Dec 3, 2019 at 10:26 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> On Tue, 3 Dec 2019 at 17:05, Enric Balletbo i Serra
> <enric.balletbo@collabora.com> wrote:
> > On 3/12/19 3:15, Krzysztof Kozlowski wrote:
> > > On Tue, 3 Dec 2019 at 05:18, Enric Balletbo i Serra
> > > <enric.balletbo@collabora.com> wrote:
> > >>
> > >> make savedefconfig result in some difference, lets normalize the
> > >> defconfig
> > >>
> > >
> > > No, for two reasons:
> > > 1. If running savedefconfig at all, split reordering items from
> > > removal of non needed options. This way we can see exactly what is
> > > being removed. This patch moves things around so it is not possible to
> > > understand what exactly you're doing here...
> >
> > Ok, makes sense, I can do it, but if you don't really care of having the
> > defconfig sync with the savedefconfig output for the below reasons or others,
> > that's fine with me.
> >
> > The reason I send the patch is because I think that, at least on some arm
> > defconfigs, they try to have the defconfig sync with the savedefconfig output,
> > the idea is to try to make patching the file easier, but I know this is usually
> > a pain.
>
> Till I saw DEBUG_FS removal and Steven's answer, I was all in in such
> patches from time to time. However now I think it's risky and instead
> manual cleanup of non-visible symbols is better.

IMHO, it's the maintainer's responsibility to refresh the defconfig(s)
regularly, from known good config(s).

I.e. you start from a known good .config, run "make oldconfig", verify
the changes by comparing the .config before/after, and run "make
savedefconfig" afterwards.

You do not run blindly "make <my>_defconfig && make savedefconfig", as
that means you'll miss out on new options you may want, and will loose
old options that are no longer selected by other options.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds