Re: [PATCH bpf-next 3/3] selftests/bpf: add benchmark testing for kprobe-multi-all
From: Andrii Nakryiko <hidden>
Date: 2025-08-20 22:54:13
Also in:
bpf, linux-kselftest, lkml, llvm
On Mon, Aug 18, 2025 at 8:40 PM Menglong Dong [off-list ref] wrote:
quoted hunk ↗ jump to hunk
For now, the benchmark for kprobe-multi is single, which means there is only 1 function is hooked during testing. Add the testing "kprobe-multi-all", which will hook all the kernel functions during the benchmark. And the "kretprobe-multi-all" is added too. Signed-off-by: Menglong Dong <redacted> --- tools/testing/selftests/bpf/bench.c | 4 ++ .../selftests/bpf/benchs/bench_trigger.c | 54 +++++++++++++++++++ .../selftests/bpf/benchs/run_bench_trigger.sh | 4 +- .../selftests/bpf/progs/trigger_bench.c | 12 +++++ tools/testing/selftests/bpf/trace_helpers.c | 3 ++ 5 files changed, 75 insertions(+), 2 deletions(-)diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c index ddd73d06a1eb..29dbf937818a 100644 --- a/tools/testing/selftests/bpf/bench.c +++ b/tools/testing/selftests/bpf/bench.c@@ -510,6 +510,8 @@ extern const struct bench bench_trig_kretprobe; extern const struct bench bench_trig_kprobe_multi; extern const struct bench bench_trig_kretprobe_multi; extern const struct bench bench_trig_fentry; +extern const struct bench bench_trig_kprobe_multi_all; +extern const struct bench bench_trig_kretprobe_multi_all; extern const struct bench bench_trig_fexit; extern const struct bench bench_trig_fmodret; extern const struct bench bench_trig_tp;@@ -578,6 +580,8 @@ static const struct bench *benchs[] = { &bench_trig_kprobe_multi, &bench_trig_kretprobe_multi, &bench_trig_fentry, + &bench_trig_kprobe_multi_all, + &bench_trig_kretprobe_multi_all, &bench_trig_fexit, &bench_trig_fmodret, &bench_trig_tp,diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c index 82327657846e..c6634a64a7c0 100644 --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c@@ -226,6 +226,58 @@ static void trigger_fentry_setup(void) attach_bpf(ctx.skel->progs.bench_trigger_fentry); } +static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + char **syms = NULL; + size_t cnt = 0; + + if (bpf_get_ksyms(&syms, &cnt, true)) { + printf("failed to get ksyms\n");
we seem to be using fprintf(stderr, "...") for emitting errors like this (at least in some benchmarks, and it makes sense to me). Do the same?
+ exit(1);
+ }
+
+ printf("found %zu ksyms\n", cnt);stray debug output?
+ opts.syms = (const char **) syms;
+ opts.cnt = cnt;
+ opts.retprobe = kretprobe;
+ /* attach empty to all the kernel functions except bpf_get_numa_node_id. */
+ if (!bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts)) {
+ printf("failed to attach bpf_program__attach_kprobe_multi_opts to all\n");
+ exit(1);
+ }
+}
+[...]