Arch Linux

ITA84

Member

Registered: 2019-10-02

Posts: 23

Question about system "freeze" with Plasma Wayland crashes

My question isn't about the cause of a specific crash with Plasma on Wayland, but rather about what happens with my system when such a crash occurs (which is more and more rare, thankfully). In most cases, when I'm on Plasma on Wayland and a full session crash occurs, my system sort of freezes: the screen either goes blank or just shows the last thing I saw before the crash, the mouse cursor moves but clicking does nothing (or it just disappears on Virtual Box, I suppose because there's no hardware cursor), no keyboard combination seems to do anything (Ctrl-Alt-F1, F2, etc.; Ctrl-Alt-Backspace; Alt-SysRq commands). The only thing that works, however, is pressing the power button to trigger a soft poweroff (ACPI shutdown).

Although the system seems frozen, it seems to perform the shutdown sequence just fine, so my question is: what is actually causing this "freeze" and is there a way to prevent it or to get back in control, given that the system can still respond to ACPI shutdown? I'm asking this because, while I've found several other user reports about Plasma on Wayland crashes, all of them seem to focus on resolving the crash, but since they seem to keep happening for various reasons, being able to avoid rebooting might be useful (especially if pacman updates are running during the crash).

I've had the system "freeze" on various setups: Intel Core i5 Sandy Bridge, AMD Phenom II + Radeon Northern Islands, Virtual Box with VMSVGA (on an Intel Core i5 Coffee Lake). The Virtual Box system is the one I can currently crash Plasma reliably upon login/startup: I've installed from the latest Arch Linux ISO, added the plasma-desktop package, plus some other stuff that may or may not be related to the crash (pipewire, xdg-desktop-portal-kde, sddm, plasma-wayland-session). Both starting the Plasma (Wayland) session from the SDDM greetwer and launching Plasma on Wayland from a tty (as described in the Wiki) result in a system "freeze" for me at the moment; it may be because of some misconfiguration or missing packages, but I don't really care about that for now, I'd like to figure out what is causing a freeze, whereas I'd expect - in the case of SDDM - to be brought back to the display manager, or at least a working tty.

I'd be grateful to anyone who could help me diagnose and debug this problem; even just pointers on where to look (documentation, code) would be appreciated.

Thanks for your attention

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,372

Re: Question about system "freeze" with Plasma Wayland crashes

Read your journal as to whether anything of significance is logged: https://wiki.archlinux.org/index.php/Sy … ing_output

ITA84

Member

Registered: 2019-10-02

Posts: 23

Re: Question about system "freeze" with Plasma Wayland crashes

I've had a look both after an SDDM login attempt and after running "XDG_SESSION_TYPE=wayland dbus-run-session startplasmacompositor" from a tty as the same user ('master'), and in both cases there didn't seem to be much information. In the latter case there are also some lines about a DBus connection error for systemd and Wayland backend auto resolution.

Journal after SDDM login:

ott 02 12:23:04 arch sddm-greeter[349]: Reading from "/usr/share/wayland-sessions/plasmawayland.desktop"
ott 02 12:23:04 arch sddm[338]: Message received from greeter: Login
ott 02 12:23:04 arch sddm[338]: Reading from "/usr/share/wayland-sessions/plasmawayland.desktop"
ott 02 12:23:04 arch sddm[338]: Reading from "/usr/share/wayland-sessions/plasmawayland.desktop"
ott 02 12:23:04 arch sddm[338]: Session "/usr/share/wayland-sessions/plasmawayland.desktop" selected, command: "dbus-run-session /usr/bin/startplasmacompositor"
ott 02 12:23:04 arch sddm-helper[398]: [PAM] Starting...
ott 02 12:23:04 arch sddm-helper[398]: [PAM] Authenticating...
ott 02 12:23:04 arch sddm-helper[398]: [PAM] Preparing to converse...
ott 02 12:23:04 arch sddm-helper[398]: [PAM] Conversation with 1 messages
ott 02 12:23:04 arch sddm-helper[398]: [PAM] returning.
ott 02 12:23:04 arch sddm[338]: Authenticated successfully
ott 02 12:23:04 arch sddm[338]: Jumping to VT 2
ott 02 12:23:04 arch sddm[338]: VT mode didn't need to be fixed
ott 02 12:23:04 arch sddm-greeter[349]: Message received from daemon: LoginSucceeded
ott 02 12:23:04 arch sddm-helper[398]: pam_unix(sddm:session): session opened for user master by (uid=0)
ott 02 12:23:04 arch kernel: audit: type=1006 audit(1570011784.393:17): pid=398 uid=0 old-auid=4294967295 auid=1000 tty=(none) old-ses=4294967295 ses=1 res=1
ott 02 12:23:04 arch systemd[1]: Created slice User Slice of UID 1000.
ott 02 12:23:04 arch systemd[1]: Starting User Runtime Directory /run/user/1000...
ott 02 12:23:04 arch systemd-logind[331]: New session 1 of user master.
ott 02 12:23:04 arch systemd[1]: Started User Runtime Directory /run/user/1000.
ott 02 12:23:04 arch audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user-runtime-dir@1000 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch kernel: audit: type=1130 audit(1570011784.426:18): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user-runtime-dir@1000 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch systemd[1]: Starting User Manager for UID 1000...
ott 02 12:23:04 arch systemd[400]: pam_unix(systemd-user:session): session opened for user master by (uid=0)
ott 02 12:23:04 arch kernel: audit: type=1006 audit(1570011784.440:19): pid=400 uid=0 old-auid=4294967295 auid=1000 tty=(none) old-ses=4294967295 ses=2 res=1
ott 02 12:23:04 arch sddm-helper[345]: [PAM] Closing session
ott 02 12:23:04 arch sddm-helper[345]: pam_unix(sddm-greeter:session): session closed for user sddm
ott 02 12:23:04 arch sddm-helper[345]: [PAM] Ended.
ott 02 12:23:04 arch systemd-logind[331]: Session c1 logged out. Waiting for processes to exit.
ott 02 12:23:04 arch systemd[1]: session-c1.scope: Succeeded.
ott 02 12:23:04 arch systemd[1]: Stopping User Runtime Directory /run/user/976...
ott 02 12:23:04 arch sddm[338]: Auth: sddm-helper exited successfully
ott 02 12:23:04 arch sddm[338]: Greeter stopped.
ott 02 12:23:04 arch systemd-logind[331]: Removed session c1.
ott 02 12:23:04 arch systemd[1]: run-user-976.mount: Succeeded.
ott 02 12:23:04 arch systemd[1]: user-runtime-dir@976.service: Succeeded.
ott 02 12:23:04 arch systemd[1]: Stopped User Runtime Directory /run/user/976.
ott 02 12:23:04 arch audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user-runtime-dir@976 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch systemd[1]: Removed slice User Slice of UID 976.
ott 02 12:23:04 arch kernel: audit: type=1131 audit(1570011784.483:20): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user-runtime-dir@976 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch systemd[400]: Reached target Paths.
ott 02 12:23:04 arch kernel: audit: type=1130 audit(1570011784.540:21): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user@1000 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=user@1000 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:04 arch systemd[400]: Reached target Timers.
ott 02 12:23:04 arch systemd[400]: Starting D-Bus User Message Bus Socket.
ott 02 12:23:04 arch systemd[400]: Listening on GnuPG network certificate management daemon.
ott 02 12:23:04 arch systemd[400]: Listening on GnuPG cryptographic agent and passphrase cache (access for web browsers).
ott 02 12:23:04 arch systemd[400]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
ott 02 12:23:04 arch systemd[400]: Listening on GnuPG cryptographic agent (ssh-agent emulation).
ott 02 12:23:04 arch systemd[400]: Listening on GnuPG cryptographic agent and passphrase cache.
ott 02 12:23:04 arch systemd[400]: Listening on p11-kit server.
ott 02 12:23:04 arch systemd[400]: Listening on Multimedia System.
ott 02 12:23:04 arch systemd[400]: Listening on D-Bus User Message Bus Socket.
ott 02 12:23:04 arch systemd[400]: Reached target Sockets.
ott 02 12:23:04 arch systemd[400]: Reached target Basic System.
ott 02 12:23:04 arch systemd[1]: Started User Manager for UID 1000.
ott 02 12:23:04 arch systemd[1]: Started Session 1 of user master.
ott 02 12:23:04 arch systemd[400]: Reached target Main User Target.
ott 02 12:23:04 arch systemd[400]: Startup finished in 94ms.
ott 02 12:23:04 arch sddm-helper[398]: Starting: "/usr/share/sddm/scripts/wayland-session dbus-run-session /usr/bin/startplasmacompositor"
ott 02 12:23:04 arch sddm[338]: Session started
ott 02 12:23:04 arch dbus-daemon[266]: [system] Activating via systemd: service name='org.freedesktop.locale1' unit='dbus-org.freedesktop.locale1.service' requested by ':1.18' (uid=1000 pid=413 comm="qdbus --system org.freedesktop.locale1 ")
ott 02 12:23:04 arch systemd[1]: Starting Locale Service...
ott 02 12:23:05 arch dbus-daemon[266]: [system] Successfully activated service 'org.freedesktop.locale1'
ott 02 12:23:05 arch audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:05 arch systemd[1]: Started Locale Service.
ott 02 12:23:05 arch kernel: audit: type=1130 audit(1570011785.056:22): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:35 arch systemd[1]: systemd-localed.service: Succeeded.
ott 02 12:23:35 arch audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:23:35 arch kernel: audit: type=1131 audit(1570011815.143:23): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'

Journal after launch from tty:

ott 02 12:45:03 arch dbus-daemon[270]: [system] Activating via systemd: service name='org.freedesktop.locale1' unit='dbus-org.freedesktop.locale1.service' requested by ':1.20' (uid=1000 pid=441 comm="qdbus --system org.freedesktop.locale1 ")
ott 02 12:45:03 arch systemd[1]: Starting Locale Service...
ott 02 12:45:04 arch dbus-daemon[270]: [system] Successfully activated service 'org.freedesktop.locale1'
ott 02 12:45:04 arch audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:45:04 arch systemd[1]: Started Locale Service.
ott 02 12:45:04 arch kernel: audit: type=1130 audit(1570013104.100:38): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:45:34 arch systemd[1]: systemd-localed.service: Succeeded.
ott 02 12:45:34 arch audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
ott 02 12:45:34 arch kernel: audit: type=1131 audit(1570013134.180:39): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-localed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'