From: Xu Kuohai <[email protected]> Add --rb-overwrite option to benchmark BPF ring buffer in overwrite mode. Since overwrite mode is not yet supported by libbpf for consumer, also add --rb-bench-producer option to benchmark producer directly without a consumer.
Benchmarks on an x86_64 and an arm64 CPU are shown below for reference. - AMD EPYC 9654 (x86_64) Ringbuf, multi-producer contention in overwrite mode, no consumer ================================================================= rb-prod nr_prod 1 32.180 ± 0.033M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 2 9.617 ± 0.003M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 3 8.810 ± 0.002M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 4 9.272 ± 0.001M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 8 9.173 ± 0.001M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 12 3.086 ± 0.032M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 16 2.945 ± 0.021M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 20 2.519 ± 0.021M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 24 2.545 ± 0.021M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 28 2.363 ± 0.024M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 32 2.357 ± 0.021M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 36 2.267 ± 0.011M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 40 2.284 ± 0.020M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 44 2.215 ± 0.025M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 48 2.193 ± 0.023M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 52 2.208 ± 0.024M/s (drops 0.000 ± 0.000M/s) - HiSilicon Kunpeng 920 (arm64) Ringbuf, multi-producer contention in overwrite mode, no consumer ================================================================= rb-prod nr_prod 1 14.478 ± 0.006M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 2 21.787 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 3 6.045 ± 0.001M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 4 5.352 ± 0.003M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 8 4.850 ± 0.002M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 12 3.542 ± 0.016M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 16 3.509 ± 0.021M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 20 3.171 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 24 3.154 ± 0.014M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 28 2.974 ± 0.015M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 32 3.167 ± 0.014M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 36 2.903 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 40 2.866 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 44 2.914 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-prod nr_prod 48 2.806 ± 0.012M/s (drops 0.000 ± 0.000M/s) Rb-prod nr_prod 52 2.840 ± 0.012M/s (drops 0.000 ± 0.000M/s) Signed-off-by: Xu Kuohai <[email protected]> --- .../selftests/bpf/benchs/bench_ringbufs.c | 66 +++++++++++++++++-- .../bpf/benchs/run_bench_ringbufs.sh | 4 ++ .../selftests/bpf/progs/ringbuf_bench.c | 11 ++++ 3 files changed, 75 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/benchs/bench_ringbufs.c b/tools/testing/selftests/bpf/benchs/bench_ringbufs.c index e1ee979e6acc..212859fb2961 100644 --- a/tools/testing/selftests/bpf/benchs/bench_ringbufs.c +++ b/tools/testing/selftests/bpf/benchs/bench_ringbufs.c @@ -19,6 +19,8 @@ static struct { int ringbuf_sz; /* per-ringbuf, in bytes */ bool ringbuf_use_output; /* use slower output API */ int perfbuf_sz; /* per-CPU size, in pages */ + bool overwrite; + bool bench_producer; } args = { .back2back = false, .batch_cnt = 500, @@ -27,6 +29,8 @@ static struct { .ringbuf_sz = 512 * 1024, .ringbuf_use_output = false, .perfbuf_sz = 128, + .overwrite = false, + .bench_producer = false, }; enum { @@ -35,6 +39,8 @@ enum { ARG_RB_BATCH_CNT = 2002, ARG_RB_SAMPLED = 2003, ARG_RB_SAMPLE_RATE = 2004, + ARG_RB_OVERWRITE = 2005, + ARG_RB_BENCH_PRODUCER = 2006, }; static const struct argp_option opts[] = { @@ -43,6 +49,8 @@ static const struct argp_option opts[] = { { "rb-batch-cnt", ARG_RB_BATCH_CNT, "CNT", 0, "Set BPF-side record batch count"}, { "rb-sampled", ARG_RB_SAMPLED, NULL, 0, "Notification sampling"}, { "rb-sample-rate", ARG_RB_SAMPLE_RATE, "RATE", 0, "Notification sample rate"}, + { "rb-overwrite", ARG_RB_OVERWRITE, NULL, 0, "Overwrite mode"}, + { "rb-bench-producer", ARG_RB_BENCH_PRODUCER, NULL, 0, "Benchmark producer"}, {}, }; @@ -72,6 +80,12 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state) argp_usage(state); } break; + case ARG_RB_OVERWRITE: + args.overwrite = true; + break; + case ARG_RB_BENCH_PRODUCER: + args.bench_producer = true; + break; default: return ARGP_ERR_UNKNOWN; } @@ -95,8 +109,33 @@ static inline void bufs_trigger_batch(void) static void bufs_validate(void) { - if (env.consumer_cnt != 1) { - fprintf(stderr, "rb-libbpf benchmark needs one consumer!\n"); + if (args.bench_producer && strcmp(env.bench_name, "rb-libbpf")) { + fprintf(stderr, "--rb-bench-producer only works with rb-libbpf!\n"); + exit(1); + } + + if (args.overwrite && !args.bench_producer) { + fprintf(stderr, "overwrite mode only works with --rb-bench-producer for now!\n"); + exit(1); + } + + if (args.bench_producer && env.consumer_cnt != 0) { + fprintf(stderr, "no consumer is needed for --rb-bench-producer!\n"); + exit(1); + } + + if (args.bench_producer && args.back2back) { + fprintf(stderr, "back-to-back mode makes no sense for --rb-bench-producer!\n"); + exit(1); + } + + if (args.bench_producer && args.sampled) { + fprintf(stderr, "sampling mode makes no sense for --rb-bench-producer!\n"); + exit(1); + } + + if (!args.bench_producer && env.consumer_cnt != 1) { + fprintf(stderr, "benchmarks without --rb-bench-producer require exactly one consumer!\n"); exit(1); } @@ -128,12 +167,17 @@ static void ringbuf_libbpf_measure(struct bench_res *res) { struct ringbuf_libbpf_ctx *ctx = &ringbuf_libbpf_ctx; - res->hits = atomic_swap(&buf_hits.value, 0); + if (args.bench_producer) + res->hits = atomic_swap(&ctx->skel->bss->hits, 0); + else + res->hits = atomic_swap(&buf_hits.value, 0); res->drops = atomic_swap(&ctx->skel->bss->dropped, 0); } static struct ringbuf_bench *ringbuf_setup_skeleton(void) { + __u32 flags; + struct bpf_map *ringbuf; struct ringbuf_bench *skel; setup_libbpf(); @@ -146,12 +190,19 @@ static struct ringbuf_bench *ringbuf_setup_skeleton(void) skel->rodata->batch_cnt = args.batch_cnt; skel->rodata->use_output = args.ringbuf_use_output ? 1 : 0; + skel->rodata->bench_producer = args.bench_producer; if (args.sampled) /* record data + header take 16 bytes */ skel->rodata->wakeup_data_size = args.sample_rate * 16; - bpf_map__set_max_entries(skel->maps.ringbuf, args.ringbuf_sz); + ringbuf = skel->maps.ringbuf; + if (args.overwrite) { + flags = bpf_map__map_flags(ringbuf) | BPF_F_RB_OVERWRITE; + bpf_map__set_map_flags(ringbuf, flags); + } + + bpf_map__set_max_entries(ringbuf, args.ringbuf_sz); if (ringbuf_bench__load(skel)) { fprintf(stderr, "failed to load skeleton\n"); @@ -171,10 +222,13 @@ static void ringbuf_libbpf_setup(void) { struct ringbuf_libbpf_ctx *ctx = &ringbuf_libbpf_ctx; struct bpf_link *link; + int map_fd; ctx->skel = ringbuf_setup_skeleton(); - ctx->ringbuf = ring_buffer__new(bpf_map__fd(ctx->skel->maps.ringbuf), - buf_process_sample, NULL, NULL); + + map_fd = bpf_map__fd(ctx->skel->maps.ringbuf); + ctx->ringbuf = ring_buffer__new(map_fd, buf_process_sample, + NULL, NULL); if (!ctx->ringbuf) { fprintf(stderr, "failed to create ringbuf\n"); exit(1); diff --git a/tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh b/tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh index 91e3567962ff..83e05e837871 100755 --- a/tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh +++ b/tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh @@ -49,3 +49,7 @@ for b in 1 2 3 4 8 12 16 20 24 28 32 36 40 44 48 52; do summarize "rb-libbpf nr_prod $b" "$($RUN_RB_BENCH -p$b --rb-batch-cnt 50 rb-libbpf)" done +header "Ringbuf, multi-producer contention in overwrite mode, no consumer" +for b in 1 2 3 4 8 12 16 20 24 28 32 36 40 44 48 52; do + summarize "rb-prod nr_prod $b" "$($RUN_BENCH -p$b --rb-batch-cnt 50 --rb-overwrite --rb-bench-producer rb-libbpf)" +done diff --git a/tools/testing/selftests/bpf/progs/ringbuf_bench.c b/tools/testing/selftests/bpf/progs/ringbuf_bench.c index 6a468496f539..d96c7d1e8fc2 100644 --- a/tools/testing/selftests/bpf/progs/ringbuf_bench.c +++ b/tools/testing/selftests/bpf/progs/ringbuf_bench.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2020 Facebook +#include <stdbool.h> #include <linux/bpf.h> #include <stdint.h> #include <bpf/bpf_helpers.h> @@ -14,9 +15,11 @@ struct { const volatile int batch_cnt = 0; const volatile long use_output = 0; +const volatile bool bench_producer = false; long sample_val = 42; long dropped __attribute__((aligned(128))) = 0; +long hits __attribute__((aligned(128))) = 0; const volatile long wakeup_data_size = 0; @@ -24,6 +27,9 @@ static __always_inline long get_flags() { long sz; + if (bench_producer) + return BPF_RB_NO_WAKEUP; + if (!wakeup_data_size) return 0; @@ -47,6 +53,8 @@ int bench_ringbuf(void *ctx) *sample = sample_val; flags = get_flags(); bpf_ringbuf_submit(sample, flags); + if (bench_producer) + __sync_add_and_fetch(&hits, 1); } } } else { @@ -55,6 +63,9 @@ int bench_ringbuf(void *ctx) if (bpf_ringbuf_output(&ringbuf, &sample_val, sizeof(sample_val), flags)) __sync_add_and_fetch(&dropped, 1); + else if (bench_producer) + __sync_add_and_fetch(&hits, 1); + } } return 0; -- 2.43.0
