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. Signed-off-by: Jiri Olsa <[email protected]> --- .../selftests/bpf/prog_tests/tracing_multi.c | 177 ++++++++++++++++++ .../selftests/bpf/progs/tracing_multi_bench.c | 13 ++ 2 files changed, 190 insertions(+) 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 ba86a88844e6..ac8ef41586f0 100644 --- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c +++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c @@ -7,6 +7,7 @@ #include "tracing_multi.skel.h" #include "tracing_multi_intersect.skel.h" #include "tracing_multi_session.skel.h" +#include "tracing_multi_bench.skel.h" #include "trace_helpers.h" static __u64 bpf_fentry_test_cookies[] = { @@ -394,6 +395,182 @@ static void test_attach_api_fails(void) tracing_multi__destroy(skel); } +/* + * Skip several kernel symbols that might not be safe or could cause delays. + */ +static bool skip_symbol(char *name) +{ + if (!strcmp(name, "arch_cpu_idle")) + return true; + if (!strcmp(name, "default_idle")) + return true; + if (!strncmp(name, "rcu_", 4)) + return true; + if (!strcmp(name, "bpf_dispatcher_xdp_func")) + return true; + if (strstr(name, "rcu")) + return true; + if (strstr(name, "trace")) + return true; + if (strstr(name, "irq")) + return true; + if (strstr(name, "bpf_lsm_")) + return true; + if (!strcmp(name, "migrate_enable")) + return true; + if (!strcmp(name, "migrate_disable")) + return true; + if (!strcmp(name, "preempt_count_sub")) + return true; + if (!strcmp(name, "preempt_count_add")) + return true; + return false; +} + +#define MAX_BPF_FUNC_ARGS 12 + +static bool btf_type_is_modifier(const struct btf_type *t) +{ + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_TYPEDEF: + case BTF_KIND_VOLATILE: + case BTF_KIND_CONST: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPE_TAG: + return true; + } + return false; +} + +static bool is_allowed_func(const struct btf *btf, const struct btf_type *t) +{ + const struct btf_type *proto; + const struct btf_param *args; + __u32 i, nargs; + __s64 ret; + + proto = btf_type_by_id(btf, t->type); + if (BTF_INFO_KIND(proto->info) != BTF_KIND_FUNC_PROTO) + return false; + + args = (const struct btf_param *)(proto + 1); + nargs = btf_vlen(proto); + if (nargs > MAX_BPF_FUNC_ARGS) + return false; + + t = btf__type_by_id(btf, proto->type); + while (t && btf_type_is_modifier(t)) + t = btf__type_by_id(btf, t->type); + + if (btf_is_struct(t) || btf_is_union(t)) + return false; + + for (i = 0; i < nargs; i++) { + /* No support for variable args */ + if (i == nargs - 1 && args[i].type == 0) + return false; + + /* No support of struct argument size greater than 16 bytes */ + ret = btf__resolve_size(btf, args[i].type); + if (ret < 0 || ret > 16) + return false; + } + + return true; +} + +void serial_test_tracing_multi_bench_attach(void) +{ + LIBBPF_OPTS(bpf_tracing_multi_opts, opts); + struct tracing_multi_bench *skel = NULL; + size_t i, syms_cnt, cap = 0, cnt = 0; + long attach_start_ns, attach_end_ns; + long detach_start_ns, detach_end_ns; + double attach_delta, detach_delta; + struct bpf_link *link = NULL; + void *root = NULL; + __u32 *ids = NULL; + __u32 nr, type_id; + struct btf *btf; + char **syms; + 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(&syms, &syms_cnt, true), "get_syms")) + goto cleanup; + + for (i = 0; i < syms_cnt; i++) { + if (skip_symbol(syms[i])) + continue; + tsearch(&syms[i], &root, compare); + } + + 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 (!is_allowed_func(btf, type)) + continue; + + err = libbpf_ensure_mem((void **) &ids, &cap, sizeof(*ids), cnt + 1); + if (err) + break; + + 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); +} + 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..067ba668489b --- /dev/null +++ b/tools/testing/selftests/bpf/progs/tracing_multi_bench.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdbool.h> +#include <linux/bpf.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; +} -- 2.52.0
