From ec151037af4f56065d5b258af82f13dbbf279ebd Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Mon, 29 Nov 2021 19:06:22 -0800 Subject: [PATCH] selftest/bpf/benchs: Add bpf_loop benchmark MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add benchmark to measure the throughput and latency of the bpf_loop call. Testing this on my dev machine on 1 thread, the data is as follows: nr_loops: 10 bpf_loop - throughput: 198.519 ± 0.155 M ops/s, latency: 5.037 ns/op nr_loops: 100 bpf_loop - throughput: 247.448 ± 0.305 M ops/s, latency: 4.041 ns/op nr_loops: 500 bpf_loop - throughput: 260.839 ± 0.380 M ops/s, latency: 3.834 ns/op nr_loops: 1000 bpf_loop - throughput: 262.806 ± 0.629 M ops/s, latency: 3.805 ns/op nr_loops: 5000 bpf_loop - throughput: 264.211 ± 1.508 M ops/s, latency: 3.785 ns/op nr_loops: 10000 bpf_loop - throughput: 265.366 ± 3.054 M ops/s, latency: 3.768 ns/op nr_loops: 50000 bpf_loop - throughput: 235.986 ± 20.205 M ops/s, latency: 4.238 ns/op nr_loops: 100000 bpf_loop - throughput: 264.482 ± 0.279 M ops/s, latency: 3.781 ns/op nr_loops: 500000 bpf_loop - throughput: 309.773 ± 87.713 M ops/s, latency: 3.228 ns/op nr_loops: 1000000 bpf_loop - throughput: 262.818 ± 4.143 M ops/s, latency: 3.805 ns/op >From this data, we can see that the latency per loop decreases as the number of loops increases. On this particular machine, each loop had an overhead of about ~4 ns, and we were able to run ~250 million loops per second. Signed-off-by: Joanne Koong Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211130030622.4131246-5-joannekoong@fb.com --- tools/testing/selftests/bpf/Makefile | 4 +- tools/testing/selftests/bpf/bench.c | 37 ++++++++ tools/testing/selftests/bpf/bench.h | 2 + .../testing/selftests/bpf/benchs/bench_bpf_loop.c | 105 +++++++++++++++++++++ .../selftests/bpf/benchs/run_bench_bpf_loop.sh | 15 +++ tools/testing/selftests/bpf/benchs/run_common.sh | 15 +++ tools/testing/selftests/bpf/progs/bpf_loop_bench.c | 26 +++++ 7 files changed, 203 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/benchs/bench_bpf_loop.c create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_bpf_loop.sh create mode 100644 tools/testing/selftests/bpf/progs/bpf_loop_bench.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 35684d6..a6c0e92 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -531,6 +531,7 @@ $(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h $(OUTPUT)/bench_ringbufs.o: $(OUTPUT)/ringbuf_bench.skel.h \ $(OUTPUT)/perfbuf_bench.skel.h $(OUTPUT)/bench_bloom_filter_map.o: $(OUTPUT)/bloom_filter_bench.skel.h +$(OUTPUT)/bench_bpf_loop.o: $(OUTPUT)/bpf_loop_bench.skel.h $(OUTPUT)/bench.o: bench.h testing_helpers.h $(BPFOBJ) $(OUTPUT)/bench: LDLIBS += -lm $(OUTPUT)/bench: $(OUTPUT)/bench.o \ @@ -540,7 +541,8 @@ $(OUTPUT)/bench: $(OUTPUT)/bench.o \ $(OUTPUT)/bench_rename.o \ $(OUTPUT)/bench_trigger.o \ $(OUTPUT)/bench_ringbufs.o \ - $(OUTPUT)/bench_bloom_filter_map.o + $(OUTPUT)/bench_bloom_filter_map.o \ + $(OUTPUT)/bench_bpf_loop.o $(call msg,BINARY,,$@) $(Q)$(CC) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@ diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c index c75e7ee..3d6082b 100644 --- a/tools/testing/selftests/bpf/bench.c +++ b/tools/testing/selftests/bpf/bench.c @@ -134,6 +134,39 @@ void hits_drops_report_final(struct bench_res res[], int res_cnt) total_ops_mean, total_ops_stddev); } +void ops_report_progress(int iter, struct bench_res *res, long delta_ns) +{ + double hits_per_sec, hits_per_prod; + + hits_per_sec = res->hits / 1000000.0 / (delta_ns / 1000000000.0); + hits_per_prod = hits_per_sec / env.producer_cnt; + + printf("Iter %3d (%7.3lfus): ", iter, (delta_ns - 1000000000) / 1000.0); + + printf("hits %8.3lfM/s (%7.3lfM/prod)\n", hits_per_sec, hits_per_prod); +} + +void ops_report_final(struct bench_res res[], int res_cnt) +{ + double hits_mean = 0.0, hits_stddev = 0.0; + int i; + + for (i = 0; i < res_cnt; i++) + hits_mean += res[i].hits / 1000000.0 / (0.0 + res_cnt); + + if (res_cnt > 1) { + for (i = 0; i < res_cnt; i++) + hits_stddev += (hits_mean - res[i].hits / 1000000.0) * + (hits_mean - res[i].hits / 1000000.0) / + (res_cnt - 1.0); + + hits_stddev = sqrt(hits_stddev); + } + printf("Summary: throughput %8.3lf \u00B1 %5.3lf M ops/s (%7.3lfM ops/prod), ", + hits_mean, hits_stddev, hits_mean / env.producer_cnt); + printf("latency %8.3lf ns/op\n", 1000.0 / hits_mean * env.producer_cnt); +} + const char *argp_program_version = "benchmark"; const char *argp_program_bug_address = ""; const char argp_program_doc[] = @@ -171,10 +204,12 @@ static const struct argp_option opts[] = { extern struct argp bench_ringbufs_argp; extern struct argp bench_bloom_map_argp; +extern struct argp bench_bpf_loop_argp; static const struct argp_child bench_parsers[] = { { &bench_ringbufs_argp, 0, "Ring buffers benchmark", 0 }, { &bench_bloom_map_argp, 0, "Bloom filter map benchmark", 0 }, + { &bench_bpf_loop_argp, 0, "bpf_loop helper benchmark", 0 }, {}, }; @@ -373,6 +408,7 @@ extern const struct bench bench_bloom_update; extern const struct bench bench_bloom_false_positive; extern const struct bench bench_hashmap_without_bloom; extern const struct bench bench_hashmap_with_bloom; +extern const struct bench bench_bpf_loop; static const struct bench *benchs[] = { &bench_count_global, @@ -404,6 +440,7 @@ static const struct bench *benchs[] = { &bench_bloom_false_positive, &bench_hashmap_without_bloom, &bench_hashmap_with_bloom, + &bench_bpf_loop, }; static void setup_benchmark() diff --git a/tools/testing/selftests/bpf/bench.h b/tools/testing/selftests/bpf/bench.h index 624c6b1..5078550 100644 --- a/tools/testing/selftests/bpf/bench.h +++ b/tools/testing/selftests/bpf/bench.h @@ -59,6 +59,8 @@ void hits_drops_report_progress(int iter, struct bench_res *res, long delta_ns); void hits_drops_report_final(struct bench_res res[], int res_cnt); void false_hits_report_progress(int iter, struct bench_res *res, long delta_ns); void false_hits_report_final(struct bench_res res[], int res_cnt); +void ops_report_progress(int iter, struct bench_res *res, long delta_ns); +void ops_report_final(struct bench_res res[], int res_cnt); static inline __u64 get_time_ns() { struct timespec t; diff --git a/tools/testing/selftests/bpf/benchs/bench_bpf_loop.c b/tools/testing/selftests/bpf/benchs/bench_bpf_loop.c new file mode 100644 index 0000000..d0a6572 --- /dev/null +++ b/tools/testing/selftests/bpf/benchs/bench_bpf_loop.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include +#include "bench.h" +#include "bpf_loop_bench.skel.h" + +/* BPF triggering benchmarks */ +static struct ctx { + struct bpf_loop_bench *skel; +} ctx; + +static struct { + __u32 nr_loops; +} args = { + .nr_loops = 10, +}; + +enum { + ARG_NR_LOOPS = 4000, +}; + +static const struct argp_option opts[] = { + { "nr_loops", ARG_NR_LOOPS, "nr_loops", 0, + "Set number of loops for the bpf_loop helper"}, + {}, +}; + +static error_t parse_arg(int key, char *arg, struct argp_state *state) +{ + switch (key) { + case ARG_NR_LOOPS: + args.nr_loops = strtol(arg, NULL, 10); + break; + default: + return ARGP_ERR_UNKNOWN; + } + + return 0; +} + +/* exported into benchmark runner */ +const struct argp bench_bpf_loop_argp = { + .options = opts, + .parser = parse_arg, +}; + +static void validate(void) +{ + if (env.consumer_cnt != 1) { + fprintf(stderr, "benchmark doesn't support multi-consumer!\n"); + exit(1); + } +} + +static void *producer(void *input) +{ + while (true) + /* trigger the bpf program */ + syscall(__NR_getpgid); + + return NULL; +} + +static void *consumer(void *input) +{ + return NULL; +} + +static void measure(struct bench_res *res) +{ + res->hits = atomic_swap(&ctx.skel->bss->hits, 0); +} + +static void setup(void) +{ + struct bpf_link *link; + + setup_libbpf(); + + ctx.skel = bpf_loop_bench__open_and_load(); + if (!ctx.skel) { + fprintf(stderr, "failed to open skeleton\n"); + exit(1); + } + + link = bpf_program__attach(ctx.skel->progs.benchmark); + if (!link) { + fprintf(stderr, "failed to attach program!\n"); + exit(1); + } + + ctx.skel->bss->nr_loops = args.nr_loops; +} + +const struct bench bench_bpf_loop = { + .name = "bpf-loop", + .validate = validate, + .setup = setup, + .producer_thread = producer, + .consumer_thread = consumer, + .measure = measure, + .report_progress = ops_report_progress, + .report_final = ops_report_final, +}; diff --git a/tools/testing/selftests/bpf/benchs/run_bench_bpf_loop.sh b/tools/testing/selftests/bpf/benchs/run_bench_bpf_loop.sh new file mode 100755 index 0000000..d4f5f73 --- /dev/null +++ b/tools/testing/selftests/bpf/benchs/run_bench_bpf_loop.sh @@ -0,0 +1,15 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +source ./benchs/run_common.sh + +set -eufo pipefail + +for t in 1 4 8 12 16; do +for i in 10 100 500 1000 5000 10000 50000 100000 500000 1000000; do +subtitle "nr_loops: $i, nr_threads: $t" + summarize_ops "bpf_loop: " \ + "$($RUN_BENCH -p $t --nr_loops $i bpf-loop)" + printf "\n" +done +done diff --git a/tools/testing/selftests/bpf/benchs/run_common.sh b/tools/testing/selftests/bpf/benchs/run_common.sh index 9a16be7..6c5e602 100644 --- a/tools/testing/selftests/bpf/benchs/run_common.sh +++ b/tools/testing/selftests/bpf/benchs/run_common.sh @@ -33,6 +33,14 @@ function percentage() echo "$*" | sed -E "s/.*Percentage\s=\s+([0-9]+\.[0-9]+).*/\1/" } +function ops() +{ + echo -n "throughput: " + echo -n "$*" | sed -E "s/.*throughput\s+([0-9]+\.[0-9]+ ± [0-9]+\.[0-9]+\sM\sops\/s).*/\1/" + echo -n -e ", latency: " + echo "$*" | sed -E "s/.*latency\s+([0-9]+\.[0-9]+\sns\/op).*/\1/" +} + function total() { echo "$*" | sed -E "s/.*total operations\s+([0-9]+\.[0-9]+ ± [0-9]+\.[0-9]+M\/s).*/\1/" @@ -52,6 +60,13 @@ function summarize_percentage() printf "%-20s %s%%\n" "$bench" "$(percentage $summary)" } +function summarize_ops() +{ + bench="$1" + summary=$(echo $2 | tail -n1) + printf "%-20s %s\n" "$bench" "$(ops $summary)" +} + function summarize_total() { bench="$1" diff --git a/tools/testing/selftests/bpf/progs/bpf_loop_bench.c b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c new file mode 100644 index 0000000..9dafdc2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include + +char _license[] SEC("license") = "GPL"; + +u32 nr_loops; +long hits; + +static int empty_callback(__u32 index, void *data) +{ + return 0; +} + +SEC("fentry/__x64_sys_getpgid") +int benchmark(void *ctx) +{ + for (int i = 0; i < 1000; i++) { + bpf_loop(nr_loops, empty_callback, NULL, 0); + + __sync_add_and_fetch(&hits, nr_loops); + } + return 0; +} -- 2.7.4