Re: [PATCHv3 bpf-next 21/26] selftests/bpf: Add uprobe_multi bench test

[Jiri Olsa <olsajiri@gmail.com>]

On Thu, Jul 06, 2023 at 09:38:20PM -0700, Andrii Nakryiko wrote:
> On Fri, Jun 30, 2023 at 1:38 AM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > Adding test that attaches 50k uprobes in uprobe_multi binary.
> >
> > After the attach is done we run the binary and make sure we
> > get proper amount of hits.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  .../bpf/prog_tests/uprobe_multi_test.c        | 56 +++++++++++++++++++
> >  .../selftests/bpf/progs/uprobe_multi.c        |  9 +++
> >  2 files changed, 65 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> > index fd858636b8b0..547d46965d70 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> > @@ -202,6 +202,60 @@ static void test_link_api(void)
> >         free(offsets);
> >  }
> >
> > +static inline __u64 get_time_ns(void)
> > +{
> > +       struct timespec t;
> > +
> > +       clock_gettime(CLOCK_MONOTONIC, &t);
> > +       return (__u64) t.tv_sec * 1000000000 + t.tv_nsec;
> > +}
> > +
> 
> hmm.. I would expect we have this helper somewhere in common headers.
> If not, we should probably move all such helpers into one header and
> use it everywhere

hum, now I see it's also defined in bench.h, I'll try to use it from
there ;-) also perhaps in kprobe multi test

> 
> > +static void test_bench_attach_uprobe(void)
> > +{
> > +       long attach_start_ns, attach_end_ns;
> > +       long detach_start_ns, detach_end_ns;
> > +       double attach_delta, detach_delta;
> > +       struct uprobe_multi *skel = NULL;
> > +       struct bpf_program *prog;
> > +       int err;
> > +
> > +       skel = uprobe_multi__open();
> > +       if (!ASSERT_OK_PTR(skel, "uprobe_multi__open"))
> > +               goto cleanup;
> > +
> > +       bpf_object__for_each_program(prog, skel->obj)
> > +               bpf_program__set_autoload(prog, false);
> > +
> > +       bpf_program__set_autoload(skel->progs.test_uprobe_bench, true);
> 
> I don't get why you bothered adding this test_uprobe_bench into
> progs/uprobe_multi and go through this manual auto-load
> setting/resetting, instead of just having test_uprobe_bench in a
> separate skeleton?...

ok, will add separate file for that.. will be simpler

> 
> > +
> > +       err = uprobe_multi__load(skel);
> > +       if (!ASSERT_EQ(err, 0, "uprobe_multi__load"))
> > +               goto cleanup;
> > +
> > +       attach_start_ns = get_time_ns();
> > +
> > +       err = uprobe_multi__attach(skel);
> > +       if (!ASSERT_OK(err, "uprobe_multi__attach"))
> > +               goto cleanup;
> > +
> > +       attach_end_ns = get_time_ns();
> > +
> > +       system("./uprobe_multi");
> > +
> > +       ASSERT_EQ(skel->bss->count, 50000, "uprobes_count");
> > +
> > +cleanup:
> > +       detach_start_ns = get_time_ns();
> > +       uprobe_multi__destroy(skel);
> > +       detach_end_ns = get_time_ns();
> > +
> > +       attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
> > +       detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
> > +
> > +       printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
> > +       printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
> 
> and for us lazy folks, what are the numbers you see on your machine?

right, will put it to the changelog

	# ./test_progs -n 260/5 -v
	bpf_testmod.ko is already unloaded.
	Loading bpf_testmod.ko...
	Successfully loaded bpf_testmod.ko.
	test_bench_attach_uprobe:PASS:uprobe_multi__open 0 nsec
	test_bench_attach_uprobe:PASS:uprobe_multi__load 0 nsec
	test_bench_attach_uprobe:PASS:uprobe_multi__attach 0 nsec
	test_bench_attach_uprobe:PASS:uprobes_count 0 nsec
	test_bench_attach_uprobe: attached in   0.398s
	test_bench_attach_uprobe: detached in   0.443s
	#260/5   uprobe_multi_test/bench_uprobe:OK
	#260     uprobe_multi_test:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
	Successfully unloaded bpf_testmod.ko.

thanks,
jirka

> 
> > +}
> > +
> >  void test_uprobe_multi_test(void)
> >  {
> >         if (test__start_subtest("skel_api"))
> > @@ -212,4 +266,6 @@ void test_uprobe_multi_test(void)
> >                 test_attach_api_syms();
> >         if (test__start_subtest("link_api"))
> >                 test_link_api();
> > +       if (test__start_subtest("bench_uprobe"))
> > +               test_bench_attach_uprobe();
> >  }
> > diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c
> > index 1eeb9b7b9cad..cd73139dc881 100644
> > --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c
> > +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c
> > @@ -89,3 +89,12 @@ int test_uretprobe_sleep(struct pt_regs *ctx)
> >         uprobe_multi_check(ctx, true, true);
> >         return 0;
> >  }
> > +
> > +int count;
> > +
> > +SEC("?uprobe.multi/./uprobe_multi:uprobe_multi_func_*")
> > +int test_uprobe_bench(struct pt_regs *ctx)
> > +{
> > +       count++;
> > +       return 0;
> > +}
> > --
> > 2.41.0
> >