Re: [PATCH bpf-next v2 4/4] selftests/bpf: Add bpf_for() benchmark

[Eduard Zingerman <eddyz87@gmail.com>]

On Fri, 2026-07-17 at 05:02 -0700, Puranjay Mohan wrote:
> The bpf_for() macro builds on the numeric open-coded iterator kfuncs
> bpf_iter_num_{new,next,destroy}(). Add a benchmark, modelled on the
> existing bpf_loop benchmark, that repeatedly runs a bpf_for() loop so the
> per-iteration cost of the iterator can be measured, e.g. to quantify the
> effect of inlining the iterator kfuncs in the verifier.
> 
> The BPF program runs an inner bpf_for(i, 0, nr_loops) loop with an empty
> body 1000 times per trigger and accounts nr_loops hits per outer
> iteration, mirroring bench_bpf_loop so the two are directly comparable.
> 
> nr_loops defaults to 1000 so that the per-iteration bpf_iter_num_next()
> cost, rather than the one-time bpf_iter_num_new()/destroy() setup and
> teardown, dominates the reported numbers:
> 
>   $ ./bench -p 1 --nr_loops 1000 bpf-for
> 
> Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
> ---

Could you please add a few tests with __xlated tag, e.g. as in:

  tools/testing/selftests/bpf/progs/epilogue_exit.c

To verify the shape of the inlined code?