examples on system tracing:

strace -e open firefox

ltrace -c ls

ptrace programming examples

dstat (disk usage while program is run)

FLAMEGRAPH and HEATMAPS
flamegraphs/heatmaps
perf record ls
perf script | ...
cat test/perf-dd-stacks-01.txt | ./stackcollapse-perf.pl | ./flamegraph.pl > /tmp/1.svg

perf-tools (many kernel level tools from Brendan Gregg, replacing much of ftrace, dtrace, systrace) see README and try

install PAPI from https://icl.utk.edu/papi/ and experiment on real Linux
system (e.g. Live USB, but not VM: why?)
