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From: Leon Hwang <leon.hwang@linux.dev>
To: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	Martin KaFai Lau <kafai@fb.com>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
	Menglong Dong <menglong8.dong@gmail.com>,
	Steven Rostedt <rostedt@kernel.org>
Subject: Re: [PATCHv4 bpf-next 24/25] selftests/bpf: Add tracing multi attach benchmark test
Date: Wed, 25 Mar 2026 14:45:31 +0800	[thread overview]
Message-ID: <7a119223-9994-4edc-af0b-f1ee9876cd20@linux.dev> (raw)
In-Reply-To: <20260324081846.2334094-25-jolsa@kernel.org>

On 24/3/26 16:18, Jiri Olsa wrote:
> Adding benchmark test that attaches to (almost) all allowed tracing
> functions and display attach/detach times.
> 
>   # ./test_progs -t tracing_multi_bench_attach -v
>   bpf_testmod.ko is already unloaded.
>   Loading bpf_testmod.ko...
>   Successfully loaded bpf_testmod.ko.
>   serial_test_tracing_multi_bench_attach:PASS:btf__load_vmlinux_btf 0 nsec
>   serial_test_tracing_multi_bench_attach:PASS:tracing_multi_bench__open_and_load 0 nsec
>   serial_test_tracing_multi_bench_attach:PASS:get_syms 0 nsec
>   serial_test_tracing_multi_bench_attach:PASS:bpf_program__attach_tracing_multi 0 nsec
>   serial_test_tracing_multi_bench_attach: found 51186 functions
>   serial_test_tracing_multi_bench_attach: attached in   1.295s
>   serial_test_tracing_multi_bench_attach: detached in   0.243s
>   #507     tracing_multi_bench_attach:OK
>   Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>   Successfully unloaded bpf_testmod.ko.
> 
> Exporting skip_entry as is_unsafe_function and using it in the test.
> 
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  .../selftests/bpf/prog_tests/tracing_multi.c  | 98 +++++++++++++++++++
>  .../selftests/bpf/progs/tracing_multi_bench.c | 12 +++
>  tools/testing/selftests/bpf/trace_helpers.c   |  6 +-
>  tools/testing/selftests/bpf/trace_helpers.h   |  1 +
>  4 files changed, 114 insertions(+), 3 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_bench.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> index dece45d8fb5e..6917471e329c 100644
> --- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> +++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
> @@ -9,6 +9,7 @@
>  #include "tracing_multi_intersect.skel.h"
>  #include "tracing_multi_session.skel.h"
>  #include "tracing_multi_fail.skel.h"
> +#include "tracing_multi_bench.skel.h"
>  #include "trace_helpers.h"
>  
>  static __u64 bpf_fentry_test_cookies[] = {
> @@ -571,6 +572,103 @@ static void test_attach_api_fails(void)
>  	free(ids2);
>  }
>  
> +void serial_test_tracing_multi_bench_attach(void)
> +{
> +	LIBBPF_OPTS(bpf_tracing_multi_opts, opts);
> +	struct tracing_multi_bench *skel = NULL;
> +	long attach_start_ns, attach_end_ns;
> +	long detach_start_ns, detach_end_ns;
> +	double attach_delta, detach_delta;
> +	struct bpf_link *link = NULL;
> +	size_t i, cap = 0, cnt = 0;
> +	struct ksyms *ksyms = NULL;
> +	void *root = NULL;
> +	__u32 *ids = NULL;
> +	__u32 nr, type_id;
> +	struct btf *btf;
> +	int err;
> +
> +#ifndef __x86_64__
> +	test__skip();
> +	return;
> +#endif
> +
> +	btf = btf__load_vmlinux_btf();
> +	if (!ASSERT_OK_PTR(btf, "btf__load_vmlinux_btf"))
> +		return;> +
> +	skel = tracing_multi_bench__open_and_load();
> +	if (!ASSERT_OK_PTR(skel, "tracing_multi_bench__open_and_load"))
> +		goto cleanup;
> +
> +	if (!ASSERT_OK(bpf_get_ksyms(&ksyms, true), "get_syms"))
> +		goto cleanup;
> +
> +	/* Get all ftrace 'safe' symbols.. */
> +	for (i = 0; i < ksyms->filtered_cnt; i++) {
> +		if (is_unsafe_function(ksyms->filtered_syms[i]))
> +			continue;
> +		tsearch(&ksyms->filtered_syms[i], &root, compare);
> +	}
> +
> +	/* ..and filter them through BTF and btf_type_is_traceable_func. */
> +	nr = btf__type_cnt(btf);
> +	for (type_id = 1; type_id < nr; type_id++) {
> +		const struct btf_type *type;
> +		const char *str;
> +
> +		type = btf__type_by_id(btf, type_id);
> +		if (!type)
> +			break;
> +
> +		if (BTF_INFO_KIND(type->info) != BTF_KIND_FUNC)
> +			continue;
> +
> +		str = btf__name_by_offset(btf, type->name_off);
> +		if (!str)
> +			break;
> +
> +		if (!tfind(&str, &root, compare))
> +			continue;
> +
> +		if (!btf_type_is_traceable_func(btf, type))
> +			continue;
> +
> +		err = libbpf_ensure_mem((void **) &ids, &cap, sizeof(*ids), cnt + 1);
> +		if (err)
> +			goto cleanup;
> +
> +		ids[cnt++] = type_id;
> +	}
> +
> +	opts.ids = ids;
> +	opts.cnt = cnt;
> +
> +	attach_start_ns = get_time_ns();
> +	link = bpf_program__attach_tracing_multi(skel->progs.bench, NULL, &opts);
> +	attach_end_ns = get_time_ns();
> +
> +	if (!ASSERT_OK_PTR(link, "bpf_program__attach_tracing_multi"))
> +		goto cleanup;
> +
> +	detach_start_ns = get_time_ns();
> +	bpf_link__destroy(link);
> +	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: found %lu functions\n", __func__, cnt);
> +	printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
> +	printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
> +
> +cleanup:
> +	tracing_multi_bench__destroy(skel);
> +	tdestroy(root, tdestroy_free_nop);
> +	free_kallsyms_local(ksyms);
> +	free(ids);

Is btf__free(btf) missing here? Since 'btf' was calloc inner
btf__load_vmlinux_btf().

Thanks,
Leon

> +}
> +
>  void test_tracing_multi_test(void)
>  {
>  #ifndef __x86_64__
> diff --git a/tools/testing/selftests/bpf/progs/tracing_multi_bench.c b/tools/testing/selftests/bpf/progs/tracing_multi_bench.c
> new file mode 100644
> index 000000000000..beae946cb8c4
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/tracing_multi_bench.c
> @@ -0,0 +1,12 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <vmlinux.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +char _license[] SEC("license") = "GPL";
> +
> +SEC("fentry.multi")
> +int BPF_PROG(bench)
> +{
> +	return 0;
> +}
> diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
> index 0e63daf83ed5..8de0b60766de 100644
> --- a/tools/testing/selftests/bpf/trace_helpers.c
> +++ b/tools/testing/selftests/bpf/trace_helpers.c
> @@ -548,7 +548,7 @@ static const char * const trace_blacklist[] = {
>  	"bpf_get_numa_node_id",
>  };
>  
> -static bool skip_entry(char *name)
> +bool is_unsafe_function(const char *name)
>  {
>  	int i;
>  
> @@ -651,7 +651,7 @@ int bpf_get_ksyms(struct ksyms **ksymsp, bool kernel)
>  		free(name);
>  		if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1)
>  			continue;
> -		if (skip_entry(name))
> +		if (is_unsafe_function(name))
>  			continue;
>  
>  		ks = search_kallsyms_custom_local(ksyms, name, search_kallsyms_compare);
> @@ -728,7 +728,7 @@ int bpf_get_addrs(unsigned long **addrsp, size_t *cntp, bool kernel)
>  		free(name);
>  		if (sscanf(buf, "%p %ms$*[^\n]\n", &addr, &name) != 2)
>  			continue;
> -		if (skip_entry(name))
> +		if (is_unsafe_function(name))
>  			continue;
>  
>  		if (cnt == max_cnt) {
> diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
> index d5bf1433675d..01c8ecc45627 100644
> --- a/tools/testing/selftests/bpf/trace_helpers.h
> +++ b/tools/testing/selftests/bpf/trace_helpers.h
> @@ -63,4 +63,5 @@ int read_build_id(const char *path, char *build_id, size_t size);
>  int bpf_get_ksyms(struct ksyms **ksymsp, bool kernel);
>  int bpf_get_addrs(unsigned long **addrsp, size_t *cntp, bool kernel);
>  
> +bool is_unsafe_function(const char *name);
>  #endif


  reply	other threads:[~2026-03-25  6:45 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-24  8:18 [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 01/25] ftrace: Add ftrace_hash_count function Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 02/25] ftrace: Make ftrace_hash_clear global Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 03/25] bpf: Use mutex lock pool for bpf trampolines Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 04/25] bpf: Add struct bpf_trampoline_ops object Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 05/25] bpf: Add struct bpf_tramp_node object Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 06/25] bpf: Factor fsession link to use struct bpf_tramp_node Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 07/25] bpf: Add multi tracing attach types Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 08/25] bpf: Move sleepable verification code to btf_id_allow_sleepable Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 09/25] bpf: Add bpf_trampoline_multi_attach/detach functions Jiri Olsa
2026-03-24  8:58   ` bot+bpf-ci
2026-03-24 14:29     ` Jiri Olsa
2026-03-27  4:18   ` kernel test robot
2026-03-24  8:18 ` [PATCHv4 bpf-next 10/25] bpf: Add support for tracing multi link Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 11/25] bpf: Add support for tracing_multi link cookies Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 12/25] bpf: Add support for tracing_multi link session Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 13/25] bpf: Add support for tracing_multi link fdinfo Jiri Olsa
2026-03-25  6:43   ` Leon Hwang
2026-03-25 21:49     ` Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 14/25] libbpf: Add bpf_object_cleanup_btf function Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 15/25] libbpf: Add bpf_link_create support for tracing_multi link Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 16/25] libbpf: Add btf_type_is_traceable_func function Jiri Olsa
2026-03-24  8:58   ` bot+bpf-ci
2026-03-24 14:29     ` Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 17/25] libbpf: Add support to create tracing multi link Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 18/25] selftests/bpf: Add tracing multi skel/pattern/ids attach tests Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 19/25] selftests/bpf: Add tracing multi skel/pattern/ids module " Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 20/25] selftests/bpf: Add tracing multi intersect tests Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 21/25] selftests/bpf: Add tracing multi cookies test Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 22/25] selftests/bpf: Add tracing multi session test Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 23/25] selftests/bpf: Add tracing multi attach fails test Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 24/25] selftests/bpf: Add tracing multi attach benchmark test Jiri Olsa
2026-03-25  6:45   ` Leon Hwang [this message]
2026-03-25 15:11     ` Alexei Starovoitov
2026-03-25 21:48       ` Jiri Olsa
2026-03-25 21:48     ` Jiri Olsa
2026-03-24  8:18 ` [PATCHv4 bpf-next 25/25] selftests/bpf: Add tracing multi attach rollback tests Jiri Olsa
2026-03-25  6:45   ` Leon Hwang
2026-03-25 21:49     ` Jiri Olsa
2026-03-25  6:42 ` [PATCHv4 bpf-next 00/25] bpf: tracing_multi link Leon Hwang
2026-03-25 14:58   ` Leon Hwang

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