Comment 34 for bug 1672297

I'm trying to track down something that makes system performance degrade in less than an hour. Whenever I switch desktops, move my cursor to a place where a tooltip is displayed, open a pull-down menu, the display freezes for 5-15 seconds before, for example, the menu or tooltip is released.

If I kill -1 my gnome-shell, performance is restored...for a while.

I decided to take some measurements.
% ps guax | grep gnome-shell
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 6.3 0.6 4037064 401804 tty2 Rl+ 10:10 1:07 /usr/bin/gnome-shell

The VSZ and RSS grow slowly, if at all, if I don't switch desktops, bring up menus, etc. Here are snapshots at 15 second intervals:
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.5 1.3 4755216 862708 tty2 Sl+ 10:10 10:41 /usr/bin/gnome-shell
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.5 1.3 4755216 862912 tty2 Sl+ 10:10 10:42 /usr/bin/gnome-shell
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.5 1.3 4755216 862912 tty2 Sl+ 10:10 10:43 /usr/bin/gnome-shell
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.5 1.3 4755216 863128 tty2 Sl+ 10:10 10:44 /usr/bin/gnome-shell
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.5 1.3 4755216 863344 tty2 Sl+ 10:10 10:45 /usr/bin/gnome-shell

After 2 hours, the ps reports go from
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 6.3 0.6 4037064 401804 tty2 Rl+ 10:10 1:07 /usr/bin/gnome-shell

to
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
skelem 15805 8.7 1.2 4725708 821640 tty2 Rl+ 10:10 11:27 /usr/bin/gnome-shell

VSZ increases by 688.6K, or 17%.
RSS increases by 419.8K, or 104%

I'm running GNOME Shell 3.26.2 on Ubuntu 17.10 x86-64.