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Sometimes, typically in the first minute after booting I get the following error on my Ubuntu 18.04 LTS setup:

Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler
[....] Shutting down cpus with NMI
[....] Kernel Offset: 0xe4000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff
[....] Rebooting in 30 seconds..

After that the machine just freezes and never reboots. The PC also has a dual boot setup with windows 10 which never crashes.

Any idea what might be causing this?

MaxJ
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  • Please add the output of sudo cat /var/log/boot.log . This might be too long to post here, so use Ubuntu pastebin if you have to. – Raffa Apr 03 '20 at 18:51
  • that boot log is empty. Is that weird? – MaxJ Apr 09 '20 at 08:34
  • No it's not weird. Instead please run journalctl --list-boots the output will list previous boots with a number on the left before each one. Please find a date and time where this issue happened during that boot. Then note the number on the left ( it might look like 0,1,2...etc or with a dash like 0,-1,-2...etc ) use the nubmer as it is with/without a dash in this command directly after -b like so journalctl -b1 or so journalctl -b-2 then add the output to Ubuntu pastebin and add the link in your question – Raffa Apr 09 '20 at 13:30

1 Answers1

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I believe this is a known bug. Apply the latest kernel with apt full-upgrade.

Alternatively, add processor.max_cstate=0 intel_idle.max_cstate=0 idle=poll to the kernel commandline editing GRUB_CMDLINE_LINUX in /etc/default/grub and running update-grub, then reboot.

More detail on editing kernel cmdline rules can be found here: https://askubuntu.com/a/19487/853283

ThankYee
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    This appears to have worked. Ran the machine for two days with the kernel settings. – MaxJ Apr 17 '20 at 12:28