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selftest/bpf: Fmod_ret prog and implement test_overhead as part of bench Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement user-space benchmarking part into benchmark runner to compare results. Results with ./bench are consistently somewhat lower than test_overhead's, but relative performance of various types of BPF programs stay consisten (e.g., kretprobe is noticeably slower). This slowdown seems to be coming from the fact that test_overhead is single-threaded, while benchmark always spins off at least one thread for producer. This has been confirmed by hacking multi-threaded test_overhead variant and also single-threaded bench variant. Resutls are below. run_bench_rename.sh script from benchs/ subdirectory was used to produce results for ./bench. Single-threaded implementations =============================== /* bench: single-threaded, atomics */ base : 4.622 ± 0.049M/s kprobe : 3.673 ± 0.052M/s kretprobe : 2.625 ± 0.052M/s rawtp : 4.369 ± 0.089M/s fentry : 4.201 ± 0.558M/s fexit : 4.309 ± 0.148M/s fmodret : 4.314 ± 0.203M/s /* selftest: single-threaded, no atomics */ task_rename base 4555K events per sec task_rename kprobe 3643K events per sec task_rename kretprobe 2506K events per sec task_rename raw_tp 4303K events per sec task_rename fentry 4307K events per sec task_rename fexit 4010K events per sec task_rename fmod_ret 3984K events per sec Multi-threaded implementations ============================== /* bench: multi-threaded w/ atomics */ base : 3.910 ± 0.023M/s kprobe : 3.048 ± 0.037M/s kretprobe : 2.300 ± 0.015M/s rawtp : 3.687 ± 0.034M/s fentry : 3.740 ± 0.087M/s fexit : 3.510 ± 0.009M/s fmodret : 3.485 ± 0.050M/s /* selftest: multi-threaded w/ atomics */ task_rename base 3872K events per sec task_rename kprobe 3068K events per sec task_rename kretprobe 2350K events per sec task_rename raw_tp 3731K events per sec task_rename fentry 3639K events per sec task_rename fexit 3558K events per sec task_rename fmod_ret 3511K events per sec /* selftest: multi-threaded, no atomics */ task_rename base 3945K events per sec task_rename kprobe 3298K events per sec task_rename kretprobe 2451K events per sec task_rename raw_tp 3718K events per sec task_rename fentry 3782K events per sec task_rename fexit 3543K events per sec task_rename fmod_ret 3526K events per sec Note that the fact that ./bench benchmark always uses atomic increments for counting, while test_overhead doesn't, doesn't influence test results all that much. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512192445.2351848-4-andriin@fb.com
2020-05-12 12:24:44 -07:00
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <fcntl.h>
#include "bench.h"
#include "test_overhead.skel.h"
/* BPF triggering benchmarks */
static struct ctx {
struct test_overhead *skel;
struct counter hits;
int fd;
} ctx;
static void validate()
{
if (env.producer_cnt != 1) {
fprintf(stderr, "benchmark doesn't support multi-producer!\n");
exit(1);
}
if (env.consumer_cnt != 1) {
fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
exit(1);
}
}
static void *producer(void *input)
{
char buf[] = "test_overhead";
int err;
while (true) {
err = write(ctx.fd, buf, sizeof(buf));
if (err < 0) {
fprintf(stderr, "write failed\n");
exit(1);
}
atomic_inc(&ctx.hits.value);
}
}
static void measure(struct bench_res *res)
{
res->hits = atomic_swap(&ctx.hits.value, 0);
}
static void setup_ctx()
{
setup_libbpf();
ctx.skel = test_overhead__open_and_load();
if (!ctx.skel) {
fprintf(stderr, "failed to open skeleton\n");
exit(1);
}
ctx.fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
if (ctx.fd < 0) {
fprintf(stderr, "failed to open /proc/self/comm: %d\n", -errno);
exit(1);
}
}
static void attach_bpf(struct bpf_program *prog)
{
struct bpf_link *link;
link = bpf_program__attach(prog);
if (IS_ERR(link)) {
fprintf(stderr, "failed to attach program!\n");
exit(1);
}
}
static void setup_base()
{
setup_ctx();
}
static void setup_kprobe()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog1);
}
static void setup_kretprobe()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog2);
}
static void setup_rawtp()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog3);
}
static void setup_fentry()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog4);
}
static void setup_fexit()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog5);
}
static void setup_fmodret()
{
setup_ctx();
attach_bpf(ctx.skel->progs.prog6);
}
static void *consumer(void *input)
{
return NULL;
}
const struct bench bench_rename_base = {
.name = "rename-base",
.validate = validate,
.setup = setup_base,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_kprobe = {
.name = "rename-kprobe",
.validate = validate,
.setup = setup_kprobe,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_kretprobe = {
.name = "rename-kretprobe",
.validate = validate,
.setup = setup_kretprobe,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_rawtp = {
.name = "rename-rawtp",
.validate = validate,
.setup = setup_rawtp,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_fentry = {
.name = "rename-fentry",
.validate = validate,
.setup = setup_fentry,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_fexit = {
.name = "rename-fexit",
.validate = validate,
.setup = setup_fexit,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};
const struct bench bench_rename_fmodret = {
.name = "rename-fmodret",
.validate = validate,
.setup = setup_fmodret,
.producer_thread = producer,
.consumer_thread = consumer,
.measure = measure,
.report_progress = hits_drops_report_progress,
.report_final = hits_drops_report_final,
};