Messages in this thread Patch in this message | | | From | Rob Landley <> | Subject | Re: [PATCH] Miniconfig revisited (2/3) | Date | Sun, 9 Jul 2006 12:45:43 -0400 |
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On Saturday 08 July 2006 12:21 pm, Horst von Brand wrote: > > +LENGTH=$(cat .config | wc -l) > > Why the cat(1)? "wc -l < .config" is the same
I believe it was originally a longer pipeline, and I can't wc the file directly or it'll spit out the filename, but < is indeed one less process spawned per loop.
> > +# Loop through all lines in the file > > +I=1 > > +while true > > +do > > + if [ $I -gt $LENGTH ] > > + then > > + break > > + fi > > Could do it with: > > for I in $(seq 1 $LENGTH); do > ... > done
Makes a 1/10th of a second difference to the final runtime, but if you prefer that...
> or just plain read the lines > > > + > > + echo -n -e "\r"$I/$LENGTH lines $(cat "$OUTPUT" | wc -c) bytes > > Again, unnecessary cat(1).
Yup, a valid cleanup.
The thing is, the script's going to be dog slow no matter what I do, and most of the slowness isn't in the script, it's the config infrastructure re-parsing the config file 1500 times or so for defconfig. (The script's about 3% of the runtime overhead, and the two largest chunks of that are printing out the progress indicator and the sed invocation right above the make.) So I didn't put that much effort into optimizing it.
Someday I'd like to go in and make kconfig spit out a miniconfig directly, but kconfig's not really set up to do that, and touching Roman Zippel's code would give him the opportunity to say no again.
Anyway, here's a version with your fixes. Thanks for the review,
Rob -- Never bet against the cheap plastic solution. --- linux-2.6.17.1/scripts/shrinkconfig 2006-07-09 12:40:38.000000000 -0400 +++ linux-2.6.17.new/scripts/shrinkconfig 2006-07-09 12:12:32.000000000 -0400 @@ -0,0 +1,79 @@ +#!/bin/bash + +# shrinkconfig copyright 2006 by Rob Landley <rob@landley.net> +# Licensed under the GNU General Public License version 2. + +if [ $# -ne 1 ] +then + echo "Turns current .config into a miniconfig file." + echo "Usage: shrinkconfig mini.config" + exit 1 +fi + +if [ ! -f .config ] +then + echo "Need a .config file to shrink." + exit 1 +fi +LENGTH=$(wc -l < .config) + +OUTPUT="$1" +cp .config "$OUTPUT" +if [ $? -ne 0 ] +then + echo "Couldn't create $OUTPUT" + exit 1 +fi + +# If we get interrupted, clean up the mess + +KERNELOUTPUT="" + +function cleanup +{ + echo + echo "Interrupted." + [ ! -z "$KERNELOUTPUT" ] && rm -rf "$KERNELOUTPUT" + rm "$OUTPUT" + exit 1 +} + +trap cleanup HUP INT QUIT TERM + +# Since the "O=" argument to make doesn't work recursively, we need to jump +# through a few hoops to avoid overwriting the .config that we're shrinking. + +# If we're building out of tree, we'll have absolute paths to source and build +# directories in the Makefile. + +KERNELSRC=$(sed -n -e 's/KERNELSRC[^/]*:=[^/]*//p' Makefile) +[ -z "$KERNELSRC" ] && KERNELSRC=$(pwd) +KERNELOUTPUT=`pwd`/.config.minitemp + +mkdir -p "$KERNELOUTPUT" || exit 1 + +echo "Shrinking .config to $OUTPUT..." + +for I in $(seq 1 $LENGTH) +do + echo -n -e "\r"$I/$LENGTH lines $(wc -c < "$OUTPUT") bytes + + sed -n "${I}!p" "$OUTPUT" > "$KERNELOUTPUT"/.config.test + # Do a config with this file + make -C "$KERNELSRC" O="$KERNELOUTPUT" allnoconfig KCONFIG_ALLCONFIG="$KERNELOUTPUT"/.config.test > /dev/null + + # Compare. The date changes, so expect a small difference each time. + D=$(diff "$KERNELOUTPUT"/.config .config | wc -l) + if [ $D -eq 4 ] + then + mv "$KERNELOUTPUT"/.config.test "$OUTPUT" + LENGTH=$[$LENGTH-1] + else + I=$[$I + 1] + fi +done + +rm -rf "$KERNELOUTPUT" + +# One extra echo to preserve status line. +echo | |