[Guillem Jover] > Hi! Hi. :)
> You asked in the past why the current implementation is the way it > is. A quick summary would be that, [...] Thank you for the explanation. :) > You should either clear the kernel cache or reboot on each iteration > to try to get a similar initial state. The former can be done with > something like: > > sudo sh -c 'sync && echo 3 > /proc/sys/vm/drop_caches' Good point. I did some more testing with such flushing in place, and tried a bit with different ordering too, and got this result installing the kde-full package and dependences (around 1700 packages): Fri Sep 19 10:39:48 CEST 2014 used: 576 dpkg_conf Fri Sep 19 10:49:09 CEST 2014 used: 558 divert Fri Sep 19 11:01:33 CEST 2014 used: 741 default Fri Sep 19 11:14:08 CEST 2014 used: 556 dpkg_conf Fri Sep 19 11:23:28 CEST 2014 used: 557 divert Fri Sep 19 11:37:57 CEST 2014 used: 866 default Fri Sep 19 12:11:27 CEST 2014 used: 930 default Fri Sep 19 12:20:54 CEST 2014 used: 564 divert Fri Sep 19 12:30:21 CEST 2014 used: 564 dpkg_conf Fri Sep 19 15:24:50 CEST 2014 used: 805 default Fri Sep 19 15:34:15 CEST 2014 used: 562 divert Fri Sep 19 15:43:40 CEST 2014 used: 562 dpkg_conf The machine had 100Mbit/s to the mirror, so most of the time is spent unpacking. The speedup seem to be significant, in the range two to three minutes for this set of packages. Also, this indicate that using eatmydata for dpkg is enough to get most of the advantage, and that using it for apt-get do not gain much extra speedup. Adding a wrapper and configuring Dir::Bin::dpkg to call it might be seen as less intrusive than the dpkg-divert method. > You might also want to try with the attached dpkg patch which should > disable all fsync() calls in the main dpkg program, to see how the > rest of the system affects your performance, besides dpkg itself. Will try to find time to do this later.:) This is the script I use for testing now. ---------------------------------------------------------------------------------------- #!/bin/sh set -e suite=testing chroot=chroot-testing #mirror=http://http.debian.net/debian mirror=http://ftp.uio.no/debian unset TMP TMPDIR TEMP TEMPDIR # Never wait for input DEBIAN_FRONTEND=noninteractive export DEBIAN_FRONTEND info() { echo info: "$@" ; } error() { echo error: "$@" ; } make_chroot() { debootstrap $suite $chroot $mirror printf "#!/bin/sh\nexit 101\n" > $chroot/usr/sbin/policy-rc.d chmod a+rx $chroot/usr/sbin/policy-rc.d chroot $chroot apt-get install -y eatmydata } install_chroot_pkgs() { chroot $chroot apt-get install -o APT::Acquire::Retries=3 -y kde-full } test_default() { make_chroot install_chroot_pkgs } test_divert() { make_chroot for bin in dpkg apt-get aptitude tasksel ; do file=/usr/bin/$bin # Test that the file exist and have not been diverted already. if [ -f $chroot/usr/bin/$bin ] ; then info "diverting /usr/bin/$bin using eatmydata" printf "#!/bin/sh\neatmydata $bin.distrib \"\$@\"\n" \ > $chroot/usr/bin/$bin.edu chmod 755 $chroot/usr/bin/$bin.edu chroot $chroot dpkg-divert --package debian-edu-config \ --rename --quiet --add /usr/bin/$bin ln -sf ./$bin.edu $chroot/usr/bin/$bin else error "unable to divert /usr/bin/$bin, as it is missing." fi done install_chroot_pkgs } # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=613428 test_dpkg_conf() { make_chroot cat > $chroot/usr/bin/dpkg-eatmydata <<'EOF' #!/bin/sh /usr/bin/eatmydata /usr/bin/dpkg "$@" EOF chmod a+rx $chroot/usr/bin/dpkg-eatmydata cat > $chroot/etc/apt/apt.conf.d/dpkg-eatmydata <<EOF Dir::Bin::dpkg "/usr/bin/dpkg-eatmydata"; EOF install_chroot_pkgs } info "Logging to run-$suite.log" exec < /dev/null > run-$suite.log 2>&1 for f in \ default \ divert \ dpkg_conf do rm -rf "$chroot" echo echo "Testing $f" echo sync && echo 3 > /proc/sys/vm/drop_caches start=$(date +%s) test_$f end=$(date +%s) (LC_ALL=C date; echo "used: $(($end - $start)) $f" ) >> test.log done echo tail test.log ---------------------------------------------------------------------------------------- -- Happy hacking Petter Reinholdtsen -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
