Evaluate recording overhead of system calls

[Mic92]

Either take a look at apache benchmark or redis benchmark
and measure what the overhead is, when perf records system calls:

$ perf record -g -e cycles -e raw_syscalls:*/call-graph=no/ \
                  -e sched:sched_switch/call-graph=no/ \
                  --switch-output --overwrite -a

https://lwn.net/Articles/694140/