I'm looking for some advice on how to troubleshoot a Dell E6400 running xubuntu 18.04. For some weeks I've run into high CPU in certain circumstances.
After watching video for around 5 minutes (in firefox, chromium, vlc or mpv) the CPU load hits 100%+ and the picture practically freezes (sound often continues). The same thing happens (or is perhaps triggered) on some websites which are not obviously running video.
Closing the app doesn't lead to recovery.
So, I'm thinking some resource has been used up or blocked but I'm looking for tips on what to narrow in on.
uname : 4.15.0-55-generic #60-Ubuntu SMP Tue Jul 2 18:21:56 UTC 2019 i686 i686 i686 GNU/Linux
Previously on this laptop I have had high cpu due to this problem, Ubuntu 18.04 systemd-udevd uses high CPU, conflict with wifi and have disabled bluetooth to workaround.
Nothing obvious in logs that I can see.