perf – performance analysis tools for Linux

Start with:

perf top
perf bench all

Example:

To find out why “kworker” process (kernel per-cpu threads) has high CPU usage:

• record 10 seconds of backtraces on all CPUs to perf.data:
  perf record -g -a sleep 10

• analyse recording:
  perf report

More info:
https://www.brendangregg.com/perf.html
https://askubuntu.com/questions/33640/kworker-what-is-it-and-why-is-it-hogging-so-much-cpu