This is a fresh and up to date install of Ubuntu 20.04 LTS.
Firefox version from dpkg -l is 89.0.2+build1-0ubuntu0.20.04.1.
Firefox freezes the desktop except the mouse, instantly or after a while.
Chromium browser does not have this problem.
After a few minutes, the Ubuntu desktop displays :
"Firefox Web Browser" is not responding.
You may choose to wait a short while for it to continue or force the application to quit entirely.
A menu follows : Force Quit or Wait but I can't click Force Quit.
Alt F2 does not prompt but I have ssh access. Output of journalctl -xe|tail -500:
juil. 12 11:29:54 mac2010-linux systemd[818]: Started Application launched by gnome-shell.
-- Subject: A start job for unit UNIT has finished successfully
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit UNIT has finished successfully.
--
-- The job identifier is 489.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 3 threads of 1 processes of 1 users.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Successfully made thread 4845 of process 4740 owned by '1000' RT at priority 10.
juil. 12 11:29:56 mac2010-linux rtkit-daemon[1007]: Supervising 4 threads of 2 processes of 1 users.
juil. 12 11:30:01 mac2010-linux CRON[4858]: pam_unix(cron:session): session opened for user root by (uid=0)
juil. 12 11:30:01 mac2010-linux CRON[4859]: (root) CMD ([ -x /etc/init.d/anacron ] && if [ ! -d /run/systemd/system ]; then /usr/sbin/invoke-rc.d anacron start >/dev/null; fi)
juil. 12 11:30:01 mac2010-linux CRON[4858]: pam_unix(cron:session): session closed for user root
juil. 12 11:30:27 mac2010-linux systemd[1]: Started Run anacron jobs.
-- Subject: A start job for unit anacron.service has finished successfully
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit anacron.service has finished successfully.
--
-- The job identifier is 1549.
juil. 12 11:30:27 mac2010-linux anacron[4862]: Anacron 2.3 started on 2021-07-12
juil. 12 11:30:27 mac2010-linux anacron[4862]: Normal exit (0 jobs run)
juil. 12 11:30:27 mac2010-linux systemd[1]: anacron.service: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit anacron.service has successfully entered the 'dead' state.
juil. 12 11:30:35 mac2010-linux wpa_supplicant[715]: wlp2s0: WPA: Group rekeying completed with 7c:8b:ca:e3:5c:da [GTK=TKIP]
juil. 12 11:30:48 mac2010-linux sshd[4860]: Accepted password for ulis from 192.168.0.156 port 54650 ssh2
The above journal excerpt is relevant because Firefox froze at 11:30 and the last line is my ssh login for inquiring.
Killing Firefox:
$ kill -9 4740
$ ps -u ulis|grep firefox
4740 ? 00:02:08 firefox
Gnome desktop remains frozen or very sluggish.
ssh terminal still responds normally.
Older journal excerpts containing "firefox":
juil. 12 10:16:32 mac2010-linux systemd[798]: gnome-launched-firefox.desktop-4935.scope: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit UNIT has successfully entered the 'dead' state.
juil. 12 10:16:54 mac2010-linux check-new-release-gtk[5243]: /usr/lib/ubuntu-release-upgrader/check-new-release-gtk:30: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version('Gtk', '3.0') before import to ensure that the right version gets loaded.
juil. 12 10:16:54 mac2010-linux check-new-release-gtk[5243]: from gi.repository import Gtk
juil. 12 10:16:54 mac2010-linux check-new-release-gtk[5243]: WARNING:root:timeout reached, exiting
juil. 12 10:16:54 mac2010-linux systemd[798]: update-notifier-release.service: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit UNIT has successfully entered the 'dead' state.
juil. 12 10:35:01 mac2010-linux systemd[798]: gnome-launched-firefox.desktop-5403.scope: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit UNIT has successfully entered the 'dead' state.
juil. 12 10:35:01 mac2010-linux kernel: nouveau 0000:04:00.0: fb: trapped read at 0100a90000 on channel -1 [0fedf000 unknown] engine 06 [BAR] client 08 [PFIFO_READ] subclient 01 [IN] reason 0000000b [VRAM_LIMIT]
juil. 12 10:35:01 mac2010-linux gnome-shell[1108]: Window manager warning: last_focus_time (3979308) is greater than comparison timestamp (3979209). This most likely represents a buggy client sending inaccurate timestamps in messages such as _NET_ACTIVE_WINDOW. Trying to work around...
juil. 12 10:35:05 mac2010-linux systemd[798]: Started Application launched by gnome-shell.
-- Subject: A start job for unit UNIT has finished successfully
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit UNIT has finished successfully.
--
juil. 12 10:38:13 mac2010-linux systemd[798]: gnome-launched-firefox.desktop-5975.scope: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit UNIT has successfully entered the 'dead' state.
juil. 12 10:38:27 mac2010-linux gnome-shell[1108]: Window manager warning: Invalid WM_TRANSIENT_FOR window 0x200000d specified for 0x200000b.
juil. 12 10:38:50 mac2010-linux systemd[798]: Started Application launched by gnome-shell.
-- Subject: A start job for unit UNIT has finished successfully
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit UNIT has finished successfully.
--
-- The job identifier is 477.
