gnome-shell hangs (goes into key repeat runaway) when key repeat is used on chromium-browser's address bar

[Chow Loong Jin]

GNOME Shell running in Wayland completely hangs when the key repeat rate is sufficiently high and used inside Chromium and/or Google Chrome. Then GNOME Shell, at-spi's dbus-daemon, ibus-daemon, and chromium-browser all get stuck at 100% CPU. GNOME Shell's RSS also quickly increases to >2GB and continues climbing.

Attempting to kill chromium-browser in a separate TTY either causes one of two things:
 - gnome-shell, dbus-daemon and ibus-daemon remain at 100% CPU and stuck; or
 - gnome-shell temporarily recovers, then crashes, taking the entire session with it and returning to the login screen.

Steps to reproduce:

1. Set key repeat rates to a high value (these are my actual settings):

$ gsettings set org.gnome.desktop.peripherals.keyboard repeat-interval 3
$ gsettings set org.gnome.desktop.peripherals.keyboard repeat true
$ gsettings set org.gnome.desktop.peripherals.keyboard delay 180

2. Start chromium-browser
3. Focus the location bar in chromium-browser
4. Press and hold a key (e.g. a) for a few seconds (~10 should do)
5. Observe that gnome-shell probably has hung by this point. If it hasn't, proceed to step 6.
6. Press and hold the backspace button until the location bar has cleared, then continue for another few seconds (~10 seconds should do)

This also affected GNOME Shell 3.24, but I was able to reduce the chances of it happening by renicing my chromium processes to +10, thereby giving GNOME Shell a greater chance at the CPU.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-shell 3.26.1-0ubuntu5
Uname: Linux 4.13.4-hyper2+ x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.7-0ubuntu3.1
Architecture: amd64
CurrentDesktop: GNOME
Date: Fri Nov 10 16:50:13 2017
DisplayManager: gdm3
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to artful on 2017-11-04 (5 days ago)

[Chow Loong Jin (hyperair)]

The key repeat runaway also happens occasionally in urxvt when the CPU is sufficiently loaded, but can be recovered by hitting the key in question again, and doesn't lead to GNOME Shell hanging.

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/GNOME. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[monkeydri (monkeydri)]

Happens also in Firefox URL bar and sometimes while typing inside Atom IDE.

Ubuntu 17.10 Gnome Shell 3.26, wayland.

[monkeydri (monkeydri)]

Actually I cannot reproduce the bug using the steps mentioned, although it did trigger high CPU use. The bug I am experiencing seems to be https://bugzilla.gnome.org/show_bug.cgi?id=777693 but so far there are no STRs, it happens randomly.

The consequence is the same though (system freeze and log out) with log message "Key repeat discarded, Wayland compositor doesn't seem to be processing events fast enough!" from gnome-shell.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.

[Attila Lendvai (attila-lendvai)]

this is super annoying! since i've installed debian 10, for me it seems like it happens everywhere randomly, or at least in most apps/contexts that i'm using. it happened around 5-10 times while editing this comment in Chromium.

my key repeat rate and delay are probably not typical:

$ gsettings get org.gnome.desktop.peripherals.keyboard repeat-interval
uint32 12
$ gsettings get org.gnome.desktop.peripherals.keyboard delay
uint32 170

[Daniel van Vugt (vanvugt)]

This bug is closed because it was only known to affect 17.10. If you are still affected then please open a new bug by running:

  ubuntu-bug gnome-shell