Based on the comment by Ilia Mirkin in Vincent's bug, I tested the current mainline (4.2.0-rc2) using Ubuntu's config (more or less following the procedure here https://wiki.ubuntu.com/KernelTeam/GitKernelBuild ).
I xscreensaver-command -lock, then logged back in (no issue there), then I xscreensaver-command -lock again and the computer just locked up. Caps lock light was unresponsive on the keyboard, Ctrl+Alt+Delete didn't work, RESIUB magic keys either. After hard rebooting the computer, here is what what in kern.log and syslog: Jul 16 17:19:45 dioo-XPS rtkit-daemon[2678]: Supervising 4 threads of 1 processes of 1 users. Jul 16 17:27:15 dioo-XPS kernel: [ 619.825758] nouveau E[ PFIFO][0000:01:00.0] SCHED_ERROR [ CTXSW_TIMEOUT ] Jul 16 17:27:15 dioo-XPS kernel: [ 619.825764] nouveau E[ PFIFO][0000:01:00.0] PGRAPH engine fault on channel 2, recovering... Jul 16 17:28:35 dioo-XPS dbus[894]: [system] Activating service name='org.freedesktop.systemd1' (using servicehelper) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1474538 Title: nouveau driver fills syslog when running xscreensaver (molecule) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-vivid/+bug/1474538/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
