[Letux-kernel] Fwd: [PATCH 2/2] ARM: configs: Cleanup old Kconfig options

H. Nikolaus Schaller hns at goldelico.com
Mon Feb 3 14:01:41 CET 2020


Fwd...

They are just discussing the same topic of cleaning up old Kconfig options and savedefconfig...

BR,
Nikolaus


> Anfang der weitergeleiteten Nachricht:
> 
> Von: Arnd Bergmann <arnd at arndb.de>
> Betreff: Aw: [PATCH 2/2] ARM: configs: Cleanup old Kconfig options
> Datum: 3. Februar 2020 um 13:25:27 MEZ
> An: Krzysztof Kozlowski <krzk at kernel.org>
> Kopie: Joe Perches <joe at perches.com>, Russell King <linux at armlinux.org.uk>, Alexander Shiyan <shc_work at mail.ru>, Uwe Kleine-König <u.kleine-koenig at pengutronix.de>, Pengutronix Kernel Team <kernel at pengutronix.de>, Shawn Guo <shawnguo at kernel.org>, Sascha Hauer <s.hauer at pengutronix.de>, Fabio Estevam <festevam at gmail.com>, NXP Linux Team <linux-imx at nxp.com>, Vladimir Zapolskiy <vz at mleia.com>, Aaro Koskinen <aaro.koskinen at iki.fi>, Tony Lindgren <tony at atomide.com>, Maxime Coquelin <mcoquelin.stm32 at gmail.com>, Alexandre Torgue <alexandre.torgue at st.com>, Liviu Dudau <liviu.dudau at arm.com>, Sudeep Holla <sudeep.holla at arm.com>, Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>, Avi Fishman <avifishman70 at gmail.com>, Tomer Maimon <tmaimon77 at gmail.com>, Tali Perry <tali.perry1 at gmail.com>, Patrick Venture <venture at google.com>, Nancy Yuen <yuenn at google.com>, Benjamin Fair <benjaminfair at google.com>, Olof Johansson <olof at lixom.net>, Linux ARM <linux-arm-kernel at lists.infradead.org>, "linux-kernel at vger.kernel.org" <linux-kernel at vger.kernel.org>, linux-omap <linux-omap at vger.kernel.org>, linux-stm32 at st-md-mailman.stormreply.com, OpenBMC Maillist <openbmc at lists.ozlabs.org>, arm-soc <arm at kernel.org>, SoC Team <soc at kernel.org>
> 
> On Mon, Feb 3, 2020 at 12:53 PM Krzysztof Kozlowski <krzk at kernel.org> wrote:
>> 
>> On Thu, 30 Jan 2020 at 23:06, Joe Perches <joe at perches.com> wrote:
>>> 
>>> On Thu, 2020-01-30 at 20:55 +0100, Krzysztof Kozlowski wrote:
>>>> CONFIG_MMC_BLOCK_BOUNCE is gone since commit c3dccb74be28 ("mmc: core:
>>>> Delete bounce buffer Kconfig option").
>>>> 
>>>> CONFIG_LBDAF is gone since commit 72deb455b5ec ("block: remove
>>>> CONFIG_LBDAF").
>>>> 
>>>> CONFIG_IOSCHED_DEADLINE and CONFIG_IOSCHED_CFQ are gone since
>>>> commit f382fb0bcef4 ("block: remove legacy IO schedulers").
>>>> 
>>>> The IOSCHED_DEADLINE was replaced by MQ_IOSCHED_DEADLINE and it will be
>>>> now enabled by default (along with MQ_IOSCHED_KYBER).
>>>> 
>>>> The IOSCHED_BFQ seems to replace IOSCHED_CFQ so select it in configs
>>>> previously choosing the latter.
>>>> 
>>>> CONFIG_CROSS_COMPILE is gone since commit f1089c92da79 ("kbuild: remove
>>>> CONFIG_CROSS_COMPILE support").
> 
> Acked-by: Arnd Bergmann <arnd at arndb.de>
> 
>>> Hi Krzysztof.
>>> 
>>> There seems there are a lot more of these unused CONFIG_<foo>
>>> symbols in various defconfigs. (just for arm and treewide below)
> 
> Feel free to pick any of these symbols and send patches for those.
> No need to do it one symbol at a time, but please group them like
> Krzysztof has done.
> 
>> Nice finding! The trickier point is to nicely remove them because:
>> 1. The easiest is 'savedefconfig' but then some valuable options might
>> disappear (like recently happened with DEBUG_FS),
>> 2. They could be removed in automated way with a script. However in
>> such case what about replacements? If some symbol was replaced with
>> other (or just renamed), maybe we should enable the other one to
>> restore the desired functionality?
>> 3. Or maybe let's don't care about keeping defconfigs stable and just
>> clean them up automatically.
> 
> I don't see a good way to do it automatically. It would be good to check
> that we don't remove Kconfig symbols that are still used in defconfig
> files without changing those files as well. Cleaning up afterwards also
> works, but this always requires manual inspection for each symbol.
> 
>     Arnd



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