1

I've been running Ubuntu on a Thinkpad T450s for some time now.

Every so often, the system will hard-lock on me. E.g. the mouse won't move, ctrl-alt-f# won't take me to a plain terminal, etc.

I haven't tried the magic sysreq key yet, and I will next time, but I'm not optimistic.

Here's a snip from journalctl from around that time (I've enabled persistent logging so that I can troubleshoot this issue):

Jul 07 16:53:27 gothputer systemd[1]: Starting Cleanup of Temporary Directories...
Jul 07 16:53:27 gothputer systemd-tmpfiles[5215]: [/usr/lib/tmpfiles.d/var.conf:14] Duplicate line for path "/var/log", ignoring.
Jul 07 16:53:27 gothputer systemd[1]: Started Cleanup of Temporary Directories.
Jul 07 16:55:13 gothputer kernel: perf interrupt took too long (5045 > 5000), lowering kernel.perf_event_max_sample_rate to 25000
Jul 07 16:57:59 gothputer systemd-timesyncd[786]: Timed out waiting for reply from 91.189.94.4:123 (ntp.ubuntu.com).
Jul 07 16:57:59 gothputer systemd-timesyncd[786]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com).
Jul 07 17:12:40 gothputer kernel: thinkpad_acpi: EC reports that Thermal Table has changed
Jul 07 17:17:01 gothputer CRON[6044]: pam_unix(cron:session): session opened for user root by (uid=0)
Jul 07 17:17:01 gothputer CRON[6045]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Jul 07 17:17:01 gothputer CRON[6044]: pam_unix(cron:session): session closed for user root
Jul 07 17:25:13 gothputer wpa_supplicant[1206]: wlp3s0: WPA: Group rekeying completed with e0:3f:49:e2:3f:c4 [GTK=CCMP]
Jul 07 17:41:35 gothputer sudo[7819]: pam_ecryptfs: pam_sm_authenticate: /home/zee is already mounted
Jul 07 17:41:35 gothputer sudo[7819]:      zee : TTY=pts/1 ; PWD=/home/zee/Downloads ; USER=root ; COMMAND=/usr/bin/gdebi N1.deb
Jul 07 17:41:35 gothputer sudo[7819]: pam_unix(sudo:session): session opened for user root by zee(uid=0)
Jul 07 17:41:43 gothputer sudo[7819]: pam_unix(sudo:session): session closed for user root
-- Reboot --
Jul 07 17:48:21 gothputer systemd-journald[313]: Runtime journal (/run/log/journal/) is 8.0M, max 118.9M, 110.9M free.
Jul 07 17:48:21 gothputer kernel: Initializing cgroup subsys cpuset
Jul 07 17:48:21 gothputer kernel: Initializing cgroup subsys cpu
Jul 07 17:48:21 gothputer kernel: Initializing cgroup subsys cpuacct
Jul 07 17:48:21 gothputer kernel: Linux version 4.4.0-28-generic (buildd@lcy01-13) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2.1) ) #47-Ubuntu SMP Fri Jun 24 10:09:13 UTC 2016 (Ubuntu
Jul 07 17:48:21 gothputer kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-4.4.0-28-generic.efi.signed root=UUID=3862c22d-6f33-42a1-8bde-d05dc9f1af16 ro quiet splash vt.handoff=7
Jul 07 17:48:21 gothputer kernel: KERNEL supported cpus:
Jul 07 17:48:21 gothputer kernel:   Intel GenuineIntel
Jul 07 17:48:21 gothputer kernel:   AMD AuthenticAMD
Jul 07 17:48:21 gothputer kernel:   Centaur CentaurHauls
Jul 07 17:48:21 gothputer kernel: x86/fpu: xstate_offset[2]:  576, xstate_sizes[2]:  256
Jul 07 17:48:21 gothputer kernel: x86/fpu: Supporting XSAVE feature 0x01: 'x87 floating point registers'
Jul 07 17:48:21 gothputer kernel: x86/fpu: Supporting XSAVE feature 0x02: 'SSE registers'
Jul 07 17:48:21 gothputer kernel: x86/fpu: Supporting XSAVE feature 0x04: 'AVX registers'
Jul 07 17:48:21 gothputer kernel: x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format.

During this particular lock-up, the clock on my desktop froze at 17:47:40, for reference.

What are the next steps here? I'm not really sure where to start short of reading every log I can find, since it's not really clear "what" is failing.

2

Things you can try when there's nothing obvious causing a lockup

  • Figure out what the max operating temperature for your CPU is from the manufacturer
  • Check in your bios or on board diagnostics if available if anything wrong can be detected (voltage, fan speed, temperatures, smart errors)
  • Shutdown X (like sudo service lightdm stop or similar) to take graphics and such out of the equation and will allow you to see console error messages
  • Install lm-sensors package and configure it. See that everything is OK from there too
  • Keep sensors running like this: watch -n1 sensors
  • Keep an eye out on dmesg output, it'll tell you all about kernel stuff
  • ALT-F1(F2, F3) to switch screens
  • Run a CPU burn in app like stress or something to heat up the CPU and sensors output. Make sure it uses all cores on your CPU.
  • Install smartmontools and run smartctl to query your hard drive and perform self tests
  • Try memtest86 or other bootable application to check your RAM. Or if you must try memtester from within Linux
  • Try bonnie++, dd or something to stress your hard drive

If all of those things seem to work out fine, I'd suspect X, especially the graphics hardware or drivers (just from past experiences). If you use Nvidia drivers, I know you can see temperature and fan speed from the GUI utility provided.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.