Backports Archive on lore.kernel.org
 help / color / Atom feed
From: Michal Marek <mmarek@suse.com>
To: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Cristina Moraru <cristina.moraru09@gmail.com>,
	"vegard.nossum@gmail.com" <vegard.nossum@gmail.com>,
	Valentin Rothberg <valentinrothberg@gmail.com>,
	Hannes Reinecke <hare@suse.de>, Sam Ravnborg <sam@ravnborg.org>,
	linux-kernel@vger.kernel.org, teg@jklm.no, kay@vrfy.org,
	rusty@rustcorp.com.au, akpm@linux-foundation.org,
	backports@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"rafael.j.wysocki" <rafael.j.wysocki@intel.com>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Takashi Iwai <tiwai@suse.de>, Christoph Hellwig <hch@lst.de>,
	Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	Hauke Mehrtens <hauke@hauke-m.de>,
	Paul Bolle <pebolle@tiscali.nl>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Alexey Khoroshilov <khoroshilov@ispras.ru>,
	Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Laurence Oberman <loberman@redhat.com>,
	Johannes Thumshirn <jthumshirn@suse.de>,
	Tejun Heo <tj@kernel.org>,
	Jej B <James.Bottomley@hansenpartnership.com>,
	Theodore Ts'o <tytso@mit.edu>,
	danijons@student.chalmers.se, Andrzej Wasowski <wasowski@itu.dk>
Subject: Re: [RFC PATCH 0/5] Add CONFIG symbol as module attribute
Date: Wed, 24 Aug 2016 13:05:04 +0200
Message-ID: <761025cd-cc36-c53f-b9cc-fe37a918644c@suse.com> (raw)
In-Reply-To: <20160823213224.GK3296@wotan.suse.de>

On 2016-08-23 23:32, Luis R. Rodriguez wrote:
> On Fri, Aug 19, 2016 at 11:07:36AM +0200, Michal Marek wrote:
>> On 2016-08-18 19:55, Luis R. Rodriguez wrote:
>>> On Wed, Aug 17, 2016 at 09:26:58PM +0200, Cristina Moraru wrote:
>>>
>>>> This patchset implements dynamic pegging of kconfig symbol
>>>> into driver modinfo section
>>>
>>> First a little bit of motivation here helps, so let me try to
>>> help fill in some gaps. This may help explain what you have
>>> been working on a bit more.
>>>
>>> First, for those that were not Cc'd but curious about this work
>>> so far, you can read the patches here:
>>>
>>> Original cover letter:
>>>
>>> https://lkml.kernel.org/r/1471462023-119645-1-git-send-email-cristina.moraru09@gmail.com
>>>
>>> https://marc.info/?l=linux-kernel&m=147146213519750&w=2 - patch 1
>>> https://marc.info/?l=linux-kernel&m=147146209019744&w=2 - patch 2
>>> https://marc.info/?l=linux-kernel&m=147146211819747&w=2 - patch 3
>>> https://marc.info/?l=linux-kernel&m=147146209119745&w=2 - patch 4
>>> https://marc.info/?l=linux-kernel&m=147146209519746&w=2 - patch 5
>>>
>>> There are a few situations in which you may want to extract a
>>> subset of Kconfig CONFIG_* symbols for a system. At least when
>>> only considering modules:
>>>
>>>  a) When optimizing build requirements for a kernel for a system.
>>>     That is you boot into a distro kernel and then want to build
>>>     a slim kernel only with sensible kernel configuration options.
>>>
>>>  b) When you are on a distribution kernel but the distribution
>>>     kernel provided lacks hardware support for your device, you
>>>     may either want to upgrade the full kernel in which case you
>>>     want to do a) or -- you may want to just a backports release
>>>     which provides just the modules you need, you'd use it on top
>>>     of the distribution kernel.
>>
>> c) Having the mapping in sysfs would allow to simplify
>> streamline_config.pl avoid parsing Makefiles in perl.
> 
> Indeed, this was actually a side possible goal here :) only it seems
> we totally forgot about it while addressing the work.
> 
>> Only if the patch did not depend on streamline_config.pl :)
> 
> Indeed, lets get rid of that dependency.
> 
>> One idea would be to generate
>> the Module.ksymb in a similar way we generate the modules.builtin file:
>> Generate an alternate include/config/*.conf with all CONFIG_FOO=m
>> replaced with
>>
>> CONFIG_FOO=m-CONFIG_FOO
>>
>> and in the Makefile, iterate over $(filter m-CONFIG_%, $(.VARIABLES)) to
                                       should be obj-m-CONFIG_%

>> create the mapping. This would also properly cover cases where we build
>> the $(obj-m) list from another list. It would certainly create other
>> corner cases, but it's worth trying IMO.
> 
> Neat, would that cover lib-m then as well or other targets that would generate 
> modules ?

This would have to be handled as well by the patch. Obviously it's not
going to be as simple as described in a single paragraph of text :).


>> Another thing is that we do not necessarily need to record this
>> information in .modinfo, but we can generate a list in
>> /lib/modules/`uname -r`/ for consumption. It could also include drivers
>> that are builtin in the current configuration.
> 
> Well so one future use would be for instance a 'make udevconfig' which
> in theory should be able then to scrape all possible related needed
> device CONFIG_'s and then give you an optimal kernel configuration.
> It'd be nice to be able to extract this from the kernel and modules
> without needing build sources in /lib/modules/`uname -r`/.

I meant that the file can be installed by modules_install. Like you have
/lib/modules/`uname -r`/modules.builtin with recent kernels and recent
distro packages. But really, it's a minor issue how the information is
presented to userspace.

Michal
--
To unsubscribe from this list: send the line "unsubscribe backports" in

  reply index

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1471462023-119645-1-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 17:55 ` Luis R. Rodriguez
2016-08-19  9:07   ` Michal Marek
2016-08-22 19:48     ` Cristina-Gabriela Moraru
2016-08-23 21:32     ` Luis R. Rodriguez
2016-08-24 11:05       ` Michal Marek [this message]
2016-08-24 16:33         ` Luis R. Rodriguez
2016-08-24 17:31           ` Naveen Kumar
2016-08-22 19:35   ` Cristina-Gabriela Moraru
2016-08-23 19:17     ` Luis R. Rodriguez
2016-08-25  7:43   ` Christoph Hellwig
2016-08-25  8:00     ` Johannes Berg
2016-08-25 19:51       ` Luis R. Rodriguez
2016-08-25  8:41     ` Michal Marek
2016-08-25 20:19     ` Luis R. Rodriguez
2019-02-05 22:07       ` Luis Chamberlain
2019-06-26 22:21         ` Luis Chamberlain
2019-06-27  4:50           ` Christoph Hellwig
2019-06-28 18:40             ` Luis Chamberlain
2019-06-29  8:42               ` Greg Kroah-Hartman
2019-07-02 20:51                 ` Luis Chamberlain
2019-07-03  7:40                   ` Greg Kroah-Hartman
2019-07-03 16:50                     ` Luis Chamberlain
2019-07-03 18:57                       ` Greg Kroah-Hartman
2019-07-03 22:25                         ` Luis Chamberlain
2019-07-11 23:07                           ` Brendan Higgins
2019-07-11 23:22                             ` Luis Chamberlain
2019-07-03 12:16               ` Enrico Weigelt, metux IT consult
2019-07-03 17:35                 ` Luis Chamberlain
2019-07-03 19:31                   ` Enrico Weigelt, metux IT consult
2019-07-03 22:42                     ` Luis Chamberlain
2019-07-11 23:27                       ` Brendan Higgins
2019-07-13 14:44                         ` Enrico Weigelt, metux IT consult
     [not found] ` <1471462023-119645-3-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 18:10   ` [RFC PATCH 2/5] Add CONFIG symbol to module as compilation parameter Luis R. Rodriguez
2016-08-18 18:55     ` Luis R. Rodriguez
2016-08-20 15:11     ` Cristina-Gabriela Moraru
2016-08-23 19:07       ` Luis R. Rodriguez
     [not found] ` <1471462023-119645-2-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 18:22   ` [RFC PATCH 1/5] Add generation of Module.symb in streamline_config Luis R. Rodriguez
2016-08-18 18:32     ` Luis R. Rodriguez
     [not found]     ` <CAGZ2q2xi9Uy-ye387=mWhy_fOEJBC593Nos7fH027m-_ZdoOXA@mail.gmail.com>
2016-08-20 14:49       ` Cristina-Gabriela Moraru
2016-08-23 19:00       ` Luis R. Rodriguez
     [not found] ` <1471462023-119645-4-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 18:30   ` [RFC PATCH 3/5] Trigger Module.ksymb generation in Makefile Luis R. Rodriguez
     [not found] ` <1471462023-119645-5-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 18:59   ` [RFC PATCH 4/5] Set KCONFIG_KSYMB as value for kconfig_ksymb module attribute Luis R. Rodriguez
2016-08-20 15:16     ` Cristina-Gabriela Moraru
2016-08-23 19:10       ` Luis R. Rodriguez
     [not found] ` <1471462023-119645-6-git-send-email-cristina.moraru09@gmail.com>
2016-08-18 19:02   ` [RFC PATCH 5/5] Add kconf_symb as kernel " Luis R. Rodriguez

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=761025cd-cc36-c53f-b9cc-fe37a918644c@suse.com \
    --to=mmarek@suse.com \
    --cc=James.Bottomley@hansenpartnership.com \
    --cc=akpm@linux-foundation.org \
    --cc=backports@vger.kernel.org \
    --cc=cristina.moraru09@gmail.com \
    --cc=danijons@student.chalmers.se \
    --cc=dmitry.torokhov@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hare@suse.de \
    --cc=hauke@hauke-m.de \
    --cc=hch@lst.de \
    --cc=johannes@sipsolutions.net \
    --cc=jthumshirn@suse.de \
    --cc=kay@vrfy.org \
    --cc=khoroshilov@ispras.ru \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=loberman@redhat.com \
    --cc=martin.petersen@oracle.com \
    --cc=mcgrof@kernel.org \
    --cc=mchehab@osg.samsung.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=pebolle@tiscali.nl \
    --cc=rafael.j.wysocki@intel.com \
    --cc=rusty@rustcorp.com.au \
    --cc=sam@ravnborg.org \
    --cc=sathya.prakash@broadcom.com \
    --cc=teg@jklm.no \
    --cc=tiwai@suse.de \
    --cc=tj@kernel.org \
    --cc=tytso@mit.edu \
    --cc=valentinrothberg@gmail.com \
    --cc=vegard.nossum@gmail.com \
    --cc=wasowski@itu.dk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Backports Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/backports/0 backports/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 backports backports/ https://lore.kernel.org/backports \
		backports@vger.kernel.org
	public-inbox-index backports

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.backports


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git