Add a minimal benchmark that measures the overhead of the batch-timing
infrastructure itself. The BPF program runs an empty BENCH_BPF_LOOP body
(~1.5-2 ns/op), establishing the floor cost that all timing-library
benchmarks include.
[root@virtme-ng tools/testing/selftests/bpf]# sudo ./bench -a -p8 bpf-nop
Setting up benchmark 'bpf-nop'...
Benchmark 'bpf-nop' started.
bpf-nop: median 1.82 ns/op, stddev 0.01, p99 1.86 (1754 samples)
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260427232313.1582588-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
