Re: [Ksummit-discuss] RFC: Kernel tinification - kernel config reduction

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Günther,

CC kbuild

On Thu, Aug 14, 2014 at 10:50 AM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 08/14/2014 12:40 AM, Geert Uytterhoeven wrote:
>>> Maybe something like
>>>
>>> make PCI=n allmodconfig
>>> make GPIOLIB=n allmodconfig
>>>
>>> which would let me disable key options selectively so I can improve
>>> compile
>>> coverage without having to go through all configurations (or randconfig).
>>
>>
>> That's doable, using KCONFIG_ALLCONFIG.
>>
> I'll play with it some more, but a quick glance (and test) suggests that I
> can
> only use it to force a configuration option to be true, not to force it to
> be false. Also, there seems to be an odd side effect.
>
> With
>         kconfig.gpio:   "CONFIG_GPIOLIB=y"
> and
>         kconfig.nogpio: "# CONFIG_GPIOLIB is not set"
>
> KCONFIG_ALLCONFIG=kconfig.gpio make allnoconfig
>         causes CONFIG_GPIOLIB to be set.
>
> KCONFIG_ALLCONFIG=kconfig.gpio make allmodconfig
> KCONFIG_ALLCONFIG=kconfig.nogpio make allmodconfig
>         both have the odd and at least for me unexpected effect of disabling
>         CONFIG_MODULES, but do not affect CONFIG_GPIOLIB.

Strange...

I also saw strange things with randconfig, needing config input during the
subsequent build, or "make oldconfig" asking new questions, just after
having done a randconfig.

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