I mentioned on the IRC channel that I was playing with a tool called Heaptrack, which I read about on Hacker News, to search for why the memory footprint of ntpd is (is it?) larger than we expect. I found a leak that ESR said looked "pretty nasty." Because I have no idea what I'm doing with debugging symbols, profilers, etc. -- I'll write down the steps to reproduce the report I'm looking at.
Here's the Heaptrack release announcement https://www.kdab.com/heaptrack-v1-1-0-release/ Here's the source code https://github.com/KDE/heaptrack I grabbed the Appimage from one of these mirrors https://download.kde.org/stable/heaptrack/1.1.0/heaptrack-v1.1.0-x86_64.AppImage.mirrorlist and saved it to my Ubuntu 16.04 box, which is named tin. # I got a fresh clone of NTPsec. ~/code $ git clone https://gitlab.com/NTPsec/ntpsec.git ~/code $ cd ntpsec # Configure for a build with debugging symbols [master]:~/code/ntpsec $ ./waf configure --enable-debug-gdb [master]:~/code/ntpsec $ ./waf build [master]:~/code/ntpsec $ sudo ./waf install # Or, if you are GEM, do this as root. Now become root in your favorite way. I didn't have luck with Heaptrack using sudo. (See, GEM is right.) #Make sure ntpd isn't running. # for systemd (my case) root@tin:~# systemctl stop ntp root@tin:~# ps -ef |grep [n]tpd # Looks good # Now start ntpd wit the Heapcheck Appimage. The -n (no fork) is important, otherwise I think you only catch ntpd dropping root. root@tin:~# /home/jazze/installers/heaptrack-v1.1.0-x86_64.AppImage /usr/sbin/ntpd -p /var/run/ntpd.pid -g -n -c /etc/ntp.conf -u 121:130 # Note, id 121:130 is ntp:ntp on my machine. ymmv Let ntpd cook for as long as needed. I don't know how long that is. In another shell, find the ntpd PID and kill it. root@tin:~# ps -ef |grep [n]tpd root 3227 28886 0 14:02 pts/21 00:00:00 /bin/bash /tmp/.mount_heaptrUKPaLq/AppRun /usr/sbin/ntpd -p /var/run/ntpd.pid -g -n -c /etc/ntp.conf -u 121:130 root 3229 4024 0 14:02 ? 00:00:00 /home/jazze/installers/heaptrack-v1.1.0-x86_64.AppImage /usr/sbin/ntpd -p /var/run/ntpd.pid -g -n -c /etc/ntp.conf -u 121:130 root 3234 3227 0 14:02 pts/21 00:00:00 /bin/sh /tmp/.mount_heaptrUKPaLq//opt/bin/heaptrack /usr/sbin/ntpd -p /var/run/ntpd.pid -g -n -c /etc/ntp.conf -u 121:130 ntp 3249 3234 2 14:02 pts/21 00:00:00 /usr/sbin/ntpd -p /var/run/ntpd.pid -g -n -c /etc/ntp.conf -u 121:130 root@tin:~# kill 3249 Now in the shell where you launched Heaptrack, you should see something like: heaptrack stats: allocations: 798 leaked allocations: 170 temporary allocations: 127 Heaptrack finished! Now run the following to investigate the data: heaptrack --analyze "/root/heaptrack.ntpd.3234.zst" The advice for launching the analyzer isn't perfect, because we're using the Appimage. Instead do: root@tin:~# /home/jazze/installers/heaptrack-v1.1.0-x86_64.AppImage --analyze "/root/heaptrack.ntpd.3234.zst" You should get a GUI report. I believe Heaptrack has some CLI-only reports, which you may find more tasteful, but I can't figure out how to get heaptrack_print. Maybe if you build from source. Best, Jason _______________________________________________ devel mailing list devel@ntpsec.org http://lists.ntpsec.org/mailman/listinfo/devel
