Merge branch 'bench-fast-in-kernel-triggering-benchmarks'

Andrii Nakryiko says:

====================
bench: fast in-kernel triggering benchmarks

Remove "legacy" triggering benchmarks which rely on syscalls (and thus syscall
overhead is a noticeable part of benchmark, unfortunately). Replace them with
faster versions that rely on triggering BPF programs in-kernel through another
simple "driver" BPF program. See patch #2 with comparison results.

raw_tp/tp/fmodret benchmarks required adding a simple kfunc in kernel to be
able to trigger a simple tracepoint from BPF program (plus it is also allowed
to be replaced by fmod_ret programs). This limits raw_tp/tp/fmodret benchmarks
to new kernels only, but it keeps bench tool itself very portable and most of
other benchmarks will still work on wide variety of kernels without the need
to worry about building and deploying custom kernel module. See patches #5
and #6 for details.

v1->v2:
  - move new TP closer to BPF test run code;
  - rename/move kfunc and register it for fmod_rets (Alexei);
  - limit --trig-batch-iters param to [1, 1000] (Alexei).
====================

Link: https://lore.kernel.org/r/20240326162151.3981687-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>