Using perf chapter

[doyougnu]

May it be a light to you in dark places, when all other lights go out.

see

• Brenden Gregg's excellent site: https://www.brendangregg.com/perf.html
• the docs: https://perf.wiki.kernel.org/index.php/Main_Page
• more docs: https://www.ibm.com/docs/en/linux-on-systems?topic=performance-getting-started-perf-command

[doyougnu]

also check in with: https://github.com/Shimuuar/tasty-papi