[PATCH 01/15] kconfig: add streamline_config.pl to scripts

Steven Rostedt
2009-09-11T20:00:35Z

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From: Steven Rostedt <srostedt@redhat.com>

streamline_config.pl is a very powerful tool. For those that install
a kernel to a new box using the config file from the distribution know that
it can take forever to compile the kernel.

Making a custom config file that will still boot your box, but bring
down the compile time of the kernel can be quit painful, and to ask
someone that reported a bug to do this can be a large burdon since that
person may not even know how to build a kernel.

This script will perform "lsmod" to find all the modules loaded on the
current running system. It will read all the Makefiles to map which
CONFIG enables a module. It will read the Kconfig files to find the
dependencies and selects that may be needed to support a CONFIG.
Finally, it reads the .config file and removes any module "=m" that is
not needed to enable the currently loaded modules. The output goes to
standard out.

Here's a way to run the script. From the Linux directory that holds
a distribution .config.

$ scripts/kconfig/streamline_config.pl arch/x86/Kconfig > config-sl
$ mv .config config-save
$ mv config-sl .config
$ make oldconfig

Now you have a .config that will still build all your modules, but also
take much less time to build the kernel.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
scripts/kconfig/streamline_config.pl | 291 ++++++++++++++++++++++++++++++++++
1 files changed, 291 insertions(+), 0 deletions(-)
create mode 100644 scripts/kconfig/streamline_config.pl

diff --git a/scripts/kconfig/streamline_config.pl b/scripts/kconfig/streamline_config.pl
new file mode 100644
index 0000000..79d8557
--- /dev/null
+++ b/scripts/kconfig/streamline_config.pl
@@ -0,0 +1,291 @@
+#!/usr/bin/perl -w
+#
+# Copywrite 2005-2009 - Steven Rostedt
+# Licensed under the terms of the GNU GPL License version 2
+#
+# It's simple enough to figure out how this works.
+# If not, then you can ask me at stripconfig@goodmis.org
+#
+# What it does?
+#
+# If you have installed a Linux kernel from a distribution
+# that turns on way too many modules than you need, and
+# you only want the modules you use, then this program
+# is perfect for you.
+#
+# It gives you the ability to turn off all the modules that are
+# not loaded on your system.
+#
+# Howto:
+#
+# 1. Boot up the kernel that you want to stream line the config on.
+# 2. Change directory to the directory holding the source of the
+# kernel that you just booted.
+# 3. Copy the configuraton file to this directory as .config
+# 4. Have all your devices that you need modules for connected and
+# operational (make sure that their corresponding modules are loaded)
+# 5. Run this script redirecting the output to some other file
+# like config_strip.
+# 6. Back up your old config (if you want too).
+# 7. copy the config_strip file to .config
+# 8. Run "make oldconfig"
+#
+# Now your kernel is ready to be built with only the modules that
+# are loaded.
+#
+# Here's what I did with my Debian distribution.
+#
+# cd /usr/src/linux-2.6.10
+# cp /boot/config-2.6.10-1-686-smp .config
+# ~/bin/streamline_config > config_strip
+# mv .config config_sav
+# mv config_strip .config
+# make oldconfig
+#
+my $config = ".config";
+my $linuxpath = ".";
+
+open(CIN,$config) || die "Can't open current config file: $config";
+my @makefiles = `find $linuxpath -name Makefile`;
+my %depends;
+my %selects;
+my %prompts;
+my %objects;
+my $var;
+my $cont = 0;
+
+# Get the top level Kconfig file (passed in)
+my $kconfig = $ARGV[0];
+
+# prevent recursion
+my %read_kconfigs;
+
+sub read_kconfig {
+ my ($kconfig) = @_;
+
+ my $state = "NONE";
+ my $config;
+ my @kconfigs;
+
+ open(KIN, $kconfig) || die "Can't open $kconfig";
+ while (<KIN>) {
+ chomp;
+
+ # collect any Kconfig sources
+ if (/^source\s*"(.*)"/) {
+ $kconfigs[$#kconfigs+1] = $1;
+ }
+
+ # configs found
+ if (/^\s*config\s+(\S+)\s*$/) {
+ $state = "NEW";
+ $config = $1;
+
+ # collect the depends for the config
+ } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
+ $state = "DEP";
+ $depends{$config} = $1;
+ } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
+ $depends{$config} .= " " . $1;
+
+ # Get the configs that select this config
+ } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
+ if (defined($selects{$1})) {
+ $selects{$1} .= " " . $config;
+ } else {
+ $selects{$1} = $config;
+ }
+
+ # configs without prompts must be selected
+ } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
+ # note if the config has a prompt
+ $prompt{$config} = 1;
+
+ # stop on "help"
+ } elsif (/^\s*help\s*$/) {
+ $state = "NONE";
+ }
+ }
+ close(KIN);
+
+ # read in any configs that were found.
+ foreach $kconfig (@kconfigs) {
+ if (!defined($read_kconfigs{$kconfig})) {
+ $read_kconfigs{$kconfig} = 1;
+ read_kconfig($kconfig);
+ }
+ }
+}
+
+if ($kconfig) {
+ read_kconfig($kconfig);
+}
+
+# Read all Makefiles to map the configs to the objects
+foreach my $makefile (@makefiles) {
+ chomp $makefile;
+
+ open(MIN,$makefile) || die "Can't open $makefile";
+ while (<MIN>) {
+ my $objs;
+
+ # is this a line after a line with a backslash?
+ if ($cont && /(\S.*)$/) {
+ $objs = $1;
+ }
+ $cont = 0;
+
+ # collect objects after obj-$(CONFIG_FOO_BAR)
+ if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
+ $var = $1;
+ $objs = $2;
+ }
+ if (defined($objs)) {
+ # test if the line ends with a backslash
+ if ($objs =~ m,(.*)\\$,) {
+ $objs = $1;
+ $cont = 1;
+ }
+
+ foreach my $obj (split /\s+/,$objs) {
+ $obj =~ s/-/_/g;
+ if ($obj =~ /(.*)\.o$/) {
+ # Objects may bes enabled by more than one config.
+ # Store configs in an array.
+ my @arr;
+
+ if (defined($objects{$1})) {
+ @arr = @{$objects{$1}};
+ }
+
+ $arr[$#arr+1] = $var;
+
+ # The objects have a hash mapping to a reference
+ # of an array of configs.
+ $objects{$1} = \@arr;
+ }
+ }
+ }
+ }
+ close(MIN);
+}
+
+my %modules;
+
+# see what modules are loaded on this system
+open(LIN,"/sbin/lsmod|") || die "Cant lsmod";
+while (<LIN>) {
+ next if (/^Module/); # Skip the first line.
+ if (/^(\S+)/) {
+ $modules{$1} = 1;
+ }
+}
+close (LIN);
+
+# add to the configs hash all configs that are needed to enable
+# a loaded module.
+my %configs;
+foreach my $module (keys(%modules)) {
+ if (defined($objects{$module})) {
+ @arr = @{$objects{$module}};
+ foreach my $conf (@arr) {
+ $configs{$conf} = $module;
+ }
+ } else {
+ # Most likely, someone has a custom (binary?) module loaded.
+ print STDERR "$module config not found!!\n";
+ }
+}
+
+my $valid = "A-Za-z_0-9";
+my $repeat = 1;
+
+#
+# Note, we do not care about operands (like: &&, ||, !) we want to add any
+# config that is in the depend list of another config. This script does
+# not enable configs that are not already enabled. If we come across a
+# config A that depends on !B, we can still add B to the list of depends
+# to keep on. If A was on in the original config, B would not have been
+# and B would not be turned on by this script.
+#
+sub parse_config_dep_select
+{
+ my ($p) = @_;
+
+ while ($p =~ /[$valid]/) {
+
+ if ($p =~ /^[^$valid]*([$valid]+)/) {
+ my $conf = "CONFIG_" . $1;
+
+ $p =~ s/^[^$valid]*[$valid]+//;
+
+ if (!defined($configs{$conf})) {
+ # We must make sure that this config has its
+ # dependencies met.
+ $repeat = 1; # do again
+ $configs{$conf} = 1;
+ }
+ } else {
+ die "this should never happen";
+ }
+ }
+}
+
+while ($repeat) {
+ $repeat = 0;
+
+ foreach my $config (keys %configs) {
+ $config =~ s/^CONFIG_//;
+
+ if (!defined($depends{$config})) {
+ next;
+ }
+
+ # This config has dependencies. Make sure they are also included
+ parse_config_dep_select $depends{$config};
+
+ if (defined($prompt{$config}) || !defined($selects{$config})) {
+ next;
+ }
+
+ # config has no prompt and must be selected.
+ parse_config_dep_select $selects{$config};
+ }
+}
+
+my %setconfigs;
+
+# Finally, read the .config file and turn off any module enabled that
+# we could not find a reason to keep enabled.
+while(<CIN>) {
+ if (/^(CONFIG.*)=m/) {
+ if (defined($configs{$1})) {
+ $setconfigs{$1} = 1;
+ print;
+ } else {
+ print "# $1 is not set\n";
+ }
+ } else {
+ print;
+ }
+}
+close(CIN);
+
+# Integrity check, make sure all modules that we want enabled do
+# indeed have their configs set.
+loop:
+foreach my $module (keys(%modules)) {
+ if (defined($objects{$module})) {
+ my @arr = @{$objects{$module}};
+ foreach my $conf (@arr) {
+ if (defined($setconfigs{$conf})) {
+ next loop;
+ }
+ }
+ print STDERR "module $module did not have configs";
+ foreach my $conf (@arr) {
+ print STDERR " " , $conf;
+ }
+ print STDERR "\n";
+ }
+}
--
1.6.3.3

--