examples on system tracing:

strace -e open firefox
ltrace -c ls
dstat (disk usage while program is run)

perf-tools (many kernel level tools, like ptrace, ftrace, dtrace, systrace)

perf record ls
perf script | ...

visualization - flamegraphs/heatmaps

cat test/perf-dd-stacks-01.txt | ./stackcollapse-perf.pl | ./flamegraph.pl > /tmp/1.svg

systemtap probe

see also: papi
