Only the main thread is targeted with --pid

[bobrik]

Currently perf_event_open targets a single PID:

ebpf-bolt/ebpf-bolt.cc

Lines 138 to 139 in 8527320

	for (i = 0; i < nr_cpus; i++) {
	fd = syscall(__NR_perf_event_open, &attr, env.pid, i, -1, 0);

Unfortunately, this actually means TID, so if you have a multithreaded program, you are missing out on quite a bit.

I think the right thing to do here is to pass the PID via BSS and do filtering in ebpf.

[aaupov]

Good point (admittedly I've only used it with single-threaded programs).