gnome-control-center starts consume memory abnormally if I try to change the background or lock screen image.

gnome-control-center starts consume memory abnormally if I try to change the background or lock screen image.

For reproduction this issue you must have a lot of pictures in ~/Pictures directory.

$ find ~/Pictures -type f | wc -l
3313

$ gnome-control-center --version
gnome-control-center 3.30.0

# rpm -q gnome-control-center
gnome-control-center-3.30.0-1.fc30.x86_64

$ ps aux --sort -rss
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
mikhail  19656  0.2 28.1 14598304 9249460 tty2 tl+  Sep14   3:14 gnome-control-center
mikhail  18409 21.8  5.8 21478115516 1918632 pts/6 Sl+ 19:05  22:01 /home/mikhail/Downloads/firefox/firefox -contentproc -childID 4 -isForBrowser -prefsLen 169 -prefMapSize 176110 -schedulerPrefs 0001,2 -parentB
mikhail  13667 22.4  4.8 21479429480 1597832 pts/6 Sl+ Sep14 330:45 /home/mikhail/Downloads/firefox/firefox
mikhail  18317 12.3  4.4 21477813636 1469784 pts/6 Sl+ 19:04  12:24 /home/mikhail/Downloads/firefox/firefox -contentproc -childID 2 -isForBrowser -prefsLen 79 -prefMapSize 176110 -schedulerPrefs 0001,2 -parentBu
qemu      3885  123  3.7 2894248 1242324 ?     Sl   Sep14 1844:21 /usr/bin/qemu-system-x86_64 -machine accel=kvm -name guest=win10,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvir
mikhail  18417  4.0  3.6 21477767500 1185960 pts/6 Dl+ 19:05   4:06 /home/mikhail/Downloads/firefox/firefox -contentproc -childID 5 -isForBrowser -prefsLen 169 -prefMapSize 176110 -schedulerPrefs 0001,2 -parentB
mikhail  18353  1.3  2.4 21476988880 791300 pts/6 Dl+ 19:05   1:20 /home/mikhail/Downloads/firefox/firefox -contentproc -childID 3 -isForBrowser -prefsLen 79 -prefMapSize 176110 -schedulerPrefs 0001,2 -parentBui
mikhail  18267  2.7  2.2 21477346828 726004 pts/6 Dl+ 19:04   2:45 /home/mikhail/Downloads/firefox/firefox -contentproc -childID 1 -isForBrowser -prefsLen 1 -prefMapSize 176110 -schedulerPrefs 0001,2 -parentBuil
mikhail  20022 11.2  1.7 2372168 566648 pts/1  SLl+ 04:31 109:22 /opt/google/chrome-unstable/chrome
mikhail  20612  1.3  1.6 1836432 541132 pts/1  Sl+  04:31  13:02 /opt/google/chrome-unstable/chrome --type=renderer --field-trial-handle=6027522647588692822,15304814186233863498,131072 --service-pipe-token=85179
mikhail   7446 86.0  1.6 1087420 529172 pts/17 Rl+  20:45   0:10 gdb -p 19656
mikhail   4585  0.6  1.2 1397104 419836 pts/2  Sl+  Sep14   9:11 /usr/lib64/opera-developer/opera-developer --type=renderer --field-trial-handle=5442091857397404156,16833416997702991072,131072 --service-pipe-tok
mikhail   3090 14.1  1.1 2813932 362660 pts/2  SLl+ Sep14 211:12 /usr/lib64/opera-developer/opera-developer

gnome-control-center-backtrace.txt

Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: author
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: email
Sep 20 02:18:23 localhost.localdomain gnome-control-c[2958]: Unknown Tag in /usr/share/gnome-background-properties/fedora-workstation-backgrounds.xml: license
Sep 20 02:18:29 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: last_focus_time (2283959) is greater than comparison timestamp (2283783).  This most likely represents a buggy client>
Sep 20 02:18:29 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: last_user_time (2283959) is greater than comparison timestamp (2283783).  This most likely represents a buggy client >
Sep 20 02:18:29 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: W1 (mikhail@lo) appears to be one of the offending windows with a timestamp of 2283959.  Working around...
Sep 20 02:18:29 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: W4 (Settings) appears to be one of the offending windows with a timestamp of 2283959.  Working around...
Sep 20 02:18:43 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: last_user_time (2297711) is greater than comparison timestamp (2297679).  This most likely represents a buggy client >
Sep 20 02:18:43 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: W1 (mikhail@lo) appears to be one of the offending windows with a timestamp of 2297711.  Working around...
Sep 20 02:18:43 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: last_user_time (2297880) is greater than comparison timestamp (2297836).  This most likely represents a buggy client >
Sep 20 02:18:43 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: W1 (mikhail@lo) appears to be one of the offending windows with a timestamp of 2297880.  Working around...
Sep 20 02:18:45 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: last_user_time (2299816) is greater than comparison timestamp (2299779).  This most likely represents a buggy client >
Sep 20 02:18:45 localhost.localdomain org.gnome.Shell.desktop[1984]: Window manager warning: W1 (mikhail@lo) appears to be one of the offending windows with a timestamp of 2299816.  Working around...