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https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-08-31 08:15:07 -04:00
dcf11479c2
Add a minimal benchmark that measures the overhead of the batch-timing infrastructure itself. The BPF program runs an empty BENCH_BPF_LOOP body (~1.5-2 ns/op), establishing the floor cost that all timing-library benchmarks include. [root@virtme-ng tools/testing/selftests/bpf]# sudo ./bench -a -p8 bpf-nop Setting up benchmark 'bpf-nop'... Benchmark 'bpf-nop' started. bpf-nop: median 1.82 ns/op, stddev 0.01, p99 1.86 (1754 samples) Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/r/20260427232313.1582588-4-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
85 lines
1.6 KiB
C
85 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
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#include "bench.h"
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#include "bench_bpf_timing.h"
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#include "bpf_nop_bench.skel.h"
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#include "bpf_util.h"
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static struct ctx {
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struct bpf_nop_bench *skel;
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struct bpf_bench_timing timing;
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int prog_fd;
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} ctx;
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static void nop_validate(void)
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{
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if (env.consumer_cnt != 0) {
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fprintf(stderr, "benchmark doesn't support consumers\n");
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exit(1);
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}
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}
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static void nop_run_once(void *unused __always_unused)
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{
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LIBBPF_OPTS(bpf_test_run_opts, topts);
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bpf_prog_test_run_opts(ctx.prog_fd, &topts);
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}
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static void nop_setup(void)
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{
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struct bpf_nop_bench *skel;
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int err;
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setup_libbpf();
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skel = bpf_nop_bench__open();
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if (!skel) {
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fprintf(stderr, "failed to open skeleton\n");
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exit(1);
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}
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err = bpf_nop_bench__load(skel);
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if (err) {
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fprintf(stderr, "failed to load skeleton: %s\n", strerror(-err));
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bpf_nop_bench__destroy(skel);
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exit(1);
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}
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ctx.skel = skel;
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ctx.prog_fd = bpf_program__fd(skel->progs.bench_nop);
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BENCH_TIMING_INIT(&ctx.timing, skel, 0);
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bpf_bench_calibrate(&ctx.timing, nop_run_once, NULL);
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env.duration_sec = 600;
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}
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static void *nop_producer(void *input)
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{
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while (true)
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nop_run_once(NULL);
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return NULL;
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}
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static void nop_measure(struct bench_res *res)
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{
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bpf_bench_timing_measure(&ctx.timing, res);
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}
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static void nop_report_final(struct bench_res res[], int res_cnt)
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{
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bpf_bench_timing_report(&ctx.timing, "bpf-nop", NULL);
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}
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const struct bench bench_bpf_nop = {
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.name = "bpf-nop",
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.validate = nop_validate,
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.setup = nop_setup,
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.producer_thread = nop_producer,
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.measure = nop_measure,
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.report_final = nop_report_final,
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};
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