Do I need to have to run
perf userspace tool as system administrator (root), or can I run it (or at least some subcommands) as an ordinary user?
kernel.perf_event_paranoid= 2: you can't take any measurements. The
perfutility might still be useful to analyse existing records with
kernel.perf_event_paranoid= 1: you can trace a command with
perf record, and get kernel profiling data.
kernel.perf_event_paranoid= 0: you can trace a command with
perf record, and get CPU event data.
kernel.perf_event_paranoid= -1: you get raw access to kernel tracepoints (specifically, you can
mmapthe file created by
perf_event_open, I don't know what the implications are).