Add multi-uprobe and multi-uretprobe benchmarks to bench tool. Multi- and classic uprobes/uretprobes have different low-level triggering code paths, so it's sometimes important to be able to benchmark both flavors of uprobes/uretprobes. Sample examples from my dev machine below. Single-threaded peformance almost doesn't differ, but with more parallel CPUs triggering the same uprobe/uretprobe the difference grows. This might be due to [0], but given the code is slightly different, there could be other sources of slowdown. Note, all these numbers will change due to ongoing work to improve uprobe/uretprobe scalability (e.g., [1]), but having benchmark like this is useful for measurements and debugging nevertheless. uprobe-nop ( 1 cpus): 1.020 ± 0.005M/s ( 1.020M/s/cpu) uretprobe-nop ( 1 cpus): 0.515 ± 0.009M/s ( 0.515M/s/cpu) uprobe-multi-nop ( 1 cpus): 1.036 ± 0.004M/s ( 1.036M/s/cpu) uretprobe-multi-nop ( 1 cpus): 0.512 ± 0.005M/s ( 0.512M/s/cpu) uprobe-nop ( 8 cpus): 3.481 ± 0.030M/s ( 0.435M/s/cpu) uretprobe-nop ( 8 cpus): 2.222 ± 0.008M/s ( 0.278M/s/cpu) uprobe-multi-nop ( 8 cpus): 3.769 ± 0.094M/s ( 0.471M/s/cpu) uretprobe-multi-nop ( 8 cpus): 2.482 ± 0.007M/s ( 0.310M/s/cpu) uprobe-nop (16 cpus): 2.968 ± 0.011M/s ( 0.185M/s/cpu) uretprobe-nop (16 cpus): 1.870 ± 0.002M/s ( 0.117M/s/cpu) uprobe-multi-nop (16 cpus): 3.541 ± 0.037M/s ( 0.221M/s/cpu) uretprobe-multi-nop (16 cpus): 2.123 ± 0.026M/s ( 0.133M/s/cpu) uprobe-nop (32 cpus): 2.524 ± 0.026M/s ( 0.079M/s/cpu) uretprobe-nop (32 cpus): 1.572 ± 0.003M/s ( 0.049M/s/cpu) uprobe-multi-nop (32 cpus): 2.717 ± 0.003M/s ( 0.085M/s/cpu) uretprobe-multi-nop (32 cpus): 1.687 ± 0.007M/s ( 0.053M/s/cpu) [0] https://lore.kernel.org/linux-trace-kernel/20240805202803.1813090-1-andrii@xxxxxxxxxx/ [1] https://lore.kernel.org/linux-trace-kernel/20240731214256.3588718-1-andrii@xxxxxxxxxx/ Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- tools/testing/selftests/bpf/bench.c | 12 +++ .../selftests/bpf/benchs/bench_trigger.c | 81 +++++++++++++++---- .../selftests/bpf/progs/trigger_bench.c | 7 ++ 3 files changed, 85 insertions(+), 15 deletions(-) diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c index 90dc3aca32bd..1bd403a5ef7b 100644 --- a/tools/testing/selftests/bpf/bench.c +++ b/tools/testing/selftests/bpf/bench.c @@ -520,6 +520,12 @@ extern const struct bench bench_trig_uprobe_push; extern const struct bench bench_trig_uretprobe_push; extern const struct bench bench_trig_uprobe_ret; extern const struct bench bench_trig_uretprobe_ret; +extern const struct bench bench_trig_uprobe_multi_nop; +extern const struct bench bench_trig_uretprobe_multi_nop; +extern const struct bench bench_trig_uprobe_multi_push; +extern const struct bench bench_trig_uretprobe_multi_push; +extern const struct bench bench_trig_uprobe_multi_ret; +extern const struct bench bench_trig_uretprobe_multi_ret; extern const struct bench bench_rb_libbpf; extern const struct bench bench_rb_custom; @@ -574,6 +580,12 @@ static const struct bench *benchs[] = { &bench_trig_uretprobe_push, &bench_trig_uprobe_ret, &bench_trig_uretprobe_ret, + &bench_trig_uprobe_multi_nop, + &bench_trig_uretprobe_multi_nop, + &bench_trig_uprobe_multi_push, + &bench_trig_uretprobe_multi_push, + &bench_trig_uprobe_multi_ret, + &bench_trig_uretprobe_multi_ret, /* ringbuf/perfbuf benchmarks */ &bench_rb_libbpf, &bench_rb_custom, diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c index 4b05539f167d..a220545a3238 100644 --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c @@ -332,7 +332,7 @@ static void *uprobe_producer_ret(void *input) return NULL; } -static void usetup(bool use_retprobe, void *target_addr) +static void usetup(bool use_retprobe, bool use_multi, void *target_addr) { size_t uprobe_offset; struct bpf_link *link; @@ -346,7 +346,10 @@ static void usetup(bool use_retprobe, void *target_addr) exit(1); } - bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe, true); + if (use_multi) + bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe_multi, true); + else + bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe, true); err = trigger_bench__load(ctx.skel); if (err) { @@ -355,16 +358,28 @@ static void usetup(bool use_retprobe, void *target_addr) } uprobe_offset = get_uprobe_offset(target_addr); - link = bpf_program__attach_uprobe(ctx.skel->progs.bench_trigger_uprobe, - use_retprobe, - -1 /* all PIDs */, - "/proc/self/exe", - uprobe_offset); + if (use_multi) { + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .retprobe = use_retprobe, + .cnt = 1, + .offsets = &uprobe_offset, + ); + link = bpf_program__attach_uprobe_multi( + ctx.skel->progs.bench_trigger_uprobe_multi, + -1 /* all PIDs */, "/proc/self/exe", NULL, &opts); + ctx.skel->links.bench_trigger_uprobe_multi = link; + } else { + link = bpf_program__attach_uprobe(ctx.skel->progs.bench_trigger_uprobe, + use_retprobe, + -1 /* all PIDs */, + "/proc/self/exe", + uprobe_offset); + ctx.skel->links.bench_trigger_uprobe = link; + } if (!link) { - fprintf(stderr, "failed to attach uprobe!\n"); + fprintf(stderr, "failed to attach %s!\n", use_multi ? "multi-uprobe" : "uprobe"); exit(1); } - ctx.skel->links.bench_trigger_uprobe = link; } static void usermode_count_setup(void) @@ -374,32 +389,62 @@ static void usermode_count_setup(void) static void uprobe_nop_setup(void) { - usetup(false, &uprobe_target_nop); + usetup(false, false /* !use_multi */, &uprobe_target_nop); } static void uretprobe_nop_setup(void) { - usetup(true, &uprobe_target_nop); + usetup(true, false /* !use_multi */, &uprobe_target_nop); } static void uprobe_push_setup(void) { - usetup(false, &uprobe_target_push); + usetup(false, false /* !use_multi */, &uprobe_target_push); } static void uretprobe_push_setup(void) { - usetup(true, &uprobe_target_push); + usetup(true, false /* !use_multi */, &uprobe_target_push); } static void uprobe_ret_setup(void) { - usetup(false, &uprobe_target_ret); + usetup(false, false /* !use_multi */, &uprobe_target_ret); } static void uretprobe_ret_setup(void) { - usetup(true, &uprobe_target_ret); + usetup(true, false /* !use_multi */, &uprobe_target_ret); +} + +static void uprobe_multi_nop_setup(void) +{ + usetup(false, true /* use_multi */, &uprobe_target_nop); +} + +static void uretprobe_multi_nop_setup(void) +{ + usetup(true, true /* use_multi */, &uprobe_target_nop); +} + +static void uprobe_multi_push_setup(void) +{ + usetup(false, true /* use_multi */, &uprobe_target_push); +} + +static void uretprobe_multi_push_setup(void) +{ + usetup(true, true /* use_multi */, &uprobe_target_push); +} + +static void uprobe_multi_ret_setup(void) +{ + usetup(false, true /* use_multi */, &uprobe_target_ret); +} + +static void uretprobe_multi_ret_setup(void) +{ + usetup(true, true /* use_multi */, &uprobe_target_ret); } const struct bench bench_trig_syscall_count = { @@ -454,3 +499,9 @@ BENCH_TRIG_USERMODE(uprobe_ret, ret, "uprobe-ret"); BENCH_TRIG_USERMODE(uretprobe_nop, nop, "uretprobe-nop"); BENCH_TRIG_USERMODE(uretprobe_push, push, "uretprobe-push"); BENCH_TRIG_USERMODE(uretprobe_ret, ret, "uretprobe-ret"); +BENCH_TRIG_USERMODE(uprobe_multi_nop, nop, "uprobe-multi-nop"); +BENCH_TRIG_USERMODE(uprobe_multi_push, push, "uprobe-multi-push"); +BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret"); +BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop"); +BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push"); +BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret"); diff --git a/tools/testing/selftests/bpf/progs/trigger_bench.c b/tools/testing/selftests/bpf/progs/trigger_bench.c index 2619ed193c65..044a6d78923e 100644 --- a/tools/testing/selftests/bpf/progs/trigger_bench.c +++ b/tools/testing/selftests/bpf/progs/trigger_bench.c @@ -32,6 +32,13 @@ int bench_trigger_uprobe(void *ctx) return 0; } +SEC("?uprobe.multi") +int bench_trigger_uprobe_multi(void *ctx) +{ + inc_counter(); + return 0; +} + const volatile int batch_iters = 0; SEC("?raw_tp") -- 2.43.5
