From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Theodore Tso <tytso@mit.edu>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
zippel@linux-m68k.org, linux-kbuild@vger.kernel.org,
Sam Ravnborg <sam@ravnborg.org>, Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH 0/3] removing unwanted module configs
Date: Thu, 30 Apr 2009 09:17:29 -0400 (EDT) [thread overview]
Message-ID: <alpine.DEB.2.00.0904300908110.20374@gandalf.stny.rr.com> (raw)
In-Reply-To: <20090430071830.GC16737@elte.hu>
On Thu, 30 Apr 2009, Ingo Molnar wrote:
>
> * Steven Rostedt <rostedt@goodmis.org> wrote:
>
> > As it has been brought up last Kernel Summit, we want to make it easier
> > for those that report bugs to build their own kernels, and maybe even
> > bisect with git. Some of these people are not programmers and do not
> > understand the complexity of the configuration options. But to compile
> > a distribution configured kernel on their boxes can take hours.
> >
> > This patch series comes to the rescue. I wrote the first instance of
> > streamline config when I bought a new box in 2005 and got frustrated
> > with finding all the necessary configurations to boot it. It is a
> > small (yet powerful) perl script.
> >
> > Here's what it does:
> >
> > * Reads the modules that are load by using lsmod.
> > * Reads all Makefiles to map modules to CONFIG_* options
> > * Reads the Kconfig files to find dependencies and selects
> > * Figures out what CONFIGS are needed to compile the loaded modules
> > * Reads the .config and prints out a version with all module configurations
> > that not needed, disabled.
> >
> > The next two patches add options to make.
> >
> > localmodconfig - this will run streamline_config.pl on the .config file
> > and replace it at the end.
> >
> > localyesconfig - this will do the same as localmodconfig but will also
> > sed -i s/=m/=y/ to turn all modules to core. It will also run
> > the 'make oldcondfig' to fix it up and let the user handle
> > andything that was changed by converting a module to core.
> >
> > Anyway, this is now in git and as a series of patches here. My git
> > tree is based off of the latest Linus git tree.
> >
> > Have fun!
>
> Very nice and useful!
>
> I have given it a try - it works to a certain degree, but does not
> seem to work fully. If i boot a Fedora distro kernel with this
> module setup:
>
> aldebaran:~/linux/linux> lsmod
> Module Size Used by
> sunrpc 253904 1
> ipv6 349568 50
> cpufreq_ondemand 73248 0
> acpi_cpufreq 75408 0
> freq_table 70400 2 cpufreq_ondemand,acpi_cpufreq
> dm_multipath 82256 0
> i2c_i801 75932 0
> i2c_core 87192 1 i2c_i801
> serio_raw 71556 0
> pcspkr 68352 0
> pata_jmicron 69504 0
> iTCO_wdt 78208 0
> shpchp 99160 0
> iTCO_vendor_support 68868 1 iTCO_wdt
> igb 144412 0
> dca 71976 1 igb
> pata_acpi 70528 0
> ata_generic 71428 0
>
> note the 'igb' driver that is essential to be picked up. 'make
> localyesconfig' complains:
>
> module igb did not have configs CONFIG_IGB
Did the original .config have it set. It will not enable any modules that
are not already set.
>
> But:
>
> # CONFIG_IGB is not set
>
> It did pick up other essential drivers - such as ext3. Why did it
> miss IGB? Here are all the missed drivers:
>
> aldebaran:~/linux/linux> make localyesconfig
> module ata_generic did not have configs CONFIG_ATA_GENERIC
> module iTCO_vendor_support did not have configs CONFIG_ITCO_WDT
> module shpchp did not have configs CONFIG_HOTPLUG_PCI_SHPC
> module acpi_cpufreq did not have configs CONFIG_IA64_ACPI_CPUFREQ CONFIG_X86_ACPI_CPUFREQ
> module pata_jmicron did not have configs CONFIG_PATA_JMICRON
> module i2c_i801 did not have configs CONFIG_I2C_I801
> module serio_raw did not have configs CONFIG_SERIO_RAW
> module iTCO_wdt did not have configs CONFIG_ITCO_WDT
> module freq_table did not have configs CONFIG_CPU_FREQ_TABLE
> module igb did not have configs CONFIG_IGB
> module ipv6 did not have configs CONFIG_IPV6
> module dca did not have configs CONFIG_DCA
> module sunrpc did not have configs CONFIG_SUNRPC
> module pata_acpi did not have configs CONFIG_PATA_ACPI
> module dm_multipath did not have configs CONFIG_DM_MULTIPATH
> module cpufreq_ondemand did not have configs
> CONFIG_CPU_FREQ_GOV_ONDEMAND
> module i2c_core did not have configs CONFIG_I2C
> module pcspkr did not have configs CONFIG_INPUT_PCSPKR
Hmm, I just added the "localyesconfig" and have not played with it much. I
need to change the integrity check of the script to test for modules that
are already compiled in (CONFIG_FOO=y). Right now it expects the modules
to be modules :-/
>
> Of those drivers, igb is the only truly boot-critical one - the box
> wont be very useful if it has no network support.
>
> Another comment: 'make localyesconfig' does not seem to be
> self-invariant. I.e. it does not handle the case well when we
> already have booted a localyesconfig kernel and do 'make
> localyesconfig' again. It will find no modules and will merrily
> create an almost empty .config.
It should not touch CONFIG_FOO=y. It should only disable the modules that
are already set but not needed.
I will update the script to not warn about modules that are compiled in.
>
> This could be addressed the following way: i think the script should
> implicitly turn on CONFIG_IKCONFIG=y, and should also check for the
> presence of /proc/config.gz and use it as a starting point. This
> makes the whole concept nicely self-invariant.
I really want to stay away from enabling anything in the .config scripts.
I can probably do it for the trivial cases. But there are cases where more
than one config will enable a module, or it takes several types of
dependencies to enable it. The script can not know which is the best set
of dependencies to enable, and I would not want to enable all of them.
But if you have a simple linier script, or no "or" cases. If we have
CONFIG_A depends on CONFIG_X && CONFIG_Y and CONFIG_X and CONFIG_Y do not
have any depends or needs to be selected, I could enable all of them if
that is the only way to enable a module. But this would come later.
Right now the goal is to remove modules that are in .config but are not
used. If CONFIG_IGB above was set (CONFIG_IGB=m) and the script disabled
it, then that would be a bug.
I will fix the warnings when the module is compiled in.
Thanks!
-- Steve
next prev parent reply other threads:[~2009-04-30 13:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-30 3:08 [PATCH 0/3] removing unwanted module configs Steven Rostedt
2009-04-30 3:08 ` [PATCH 1/3] kconfig: add streamline_config.pl to scripts Steven Rostedt
2009-04-30 3:08 ` [PATCH 2/3] kconfig: make localmodconfig to run streamline_config.pl Steven Rostedt
2009-04-30 3:08 ` [PATCH 3/3] kconfig: add make localyesconfig option Steven Rostedt
2009-04-30 7:18 ` [PATCH 0/3] removing unwanted module configs Ingo Molnar
2009-04-30 13:17 ` Steven Rostedt [this message]
2009-04-30 13:26 ` Ingo Molnar
2009-04-30 13:42 ` Steven Rostedt
2009-04-30 13:47 ` Steven Rostedt
2009-04-30 14:43 ` Ingo Molnar
2009-04-30 14:42 ` Ingo Molnar
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