diff options
Diffstat (limited to 'samples/bpf/test_overhead_user.c')
| -rw-r--r-- | samples/bpf/test_overhead_user.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c new file mode 100644 index 000000000..88717f8ec --- /dev/null +++ b/samples/bpf/test_overhead_user.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2016 Facebook + */ +#define _GNU_SOURCE +#include <sched.h> +#include <errno.h> +#include <stdio.h> +#include <sys/types.h> +#include <asm/unistd.h> +#include <fcntl.h> +#include <unistd.h> +#include <assert.h> +#include <sys/wait.h> +#include <stdlib.h> +#include <signal.h> +#include <linux/bpf.h> +#include <string.h> +#include <time.h> +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +#define MAX_CNT 1000000 + +static struct bpf_link *links[2]; +static struct bpf_object *obj; +static int cnt; + +static __u64 time_get_ns(void) +{ + struct timespec ts; + + clock_gettime(CLOCK_MONOTONIC, &ts); + return ts.tv_sec * 1000000000ull + ts.tv_nsec; +} + +static void test_task_rename(int cpu) +{ + __u64 start_time; + char buf[] = "test\n"; + int i, fd; + + fd = open("/proc/self/comm", O_WRONLY|O_TRUNC); + if (fd < 0) { + printf("couldn't open /proc\n"); + exit(1); + } + start_time = time_get_ns(); + for (i = 0; i < MAX_CNT; i++) { + if (write(fd, buf, sizeof(buf)) < 0) { + printf("task rename failed: %s\n", strerror(errno)); + close(fd); + return; + } + } + printf("task_rename:%d: %lld events per sec\n", + cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); + close(fd); +} + +static void test_urandom_read(int cpu) +{ + __u64 start_time; + char buf[4]; + int i, fd; + + fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) { + printf("couldn't open /dev/urandom\n"); + exit(1); + } + start_time = time_get_ns(); + for (i = 0; i < MAX_CNT; i++) { + if (read(fd, buf, sizeof(buf)) < 0) { + printf("failed to read from /dev/urandom: %s\n", strerror(errno)); + close(fd); + return; + } + } + printf("urandom_read:%d: %lld events per sec\n", + cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); + close(fd); +} + +static void loop(int cpu, int flags) +{ + cpu_set_t cpuset; + + CPU_ZERO(&cpuset); + CPU_SET(cpu, &cpuset); + sched_setaffinity(0, sizeof(cpuset), &cpuset); + + if (flags & 1) + test_task_rename(cpu); + if (flags & 2) + test_urandom_read(cpu); +} + +static void run_perf_test(int tasks, int flags) +{ + pid_t pid[tasks]; + int i; + + for (i = 0; i < tasks; i++) { + pid[i] = fork(); + if (pid[i] == 0) { + loop(i, flags); + exit(0); + } else if (pid[i] == -1) { + printf("couldn't spawn #%d process\n", i); + exit(1); + } + } + for (i = 0; i < tasks; i++) { + int status; + + assert(waitpid(pid[i], &status, 0) == pid[i]); + assert(status == 0); + } +} + +static int load_progs(char *filename) +{ + struct bpf_program *prog; + int err = 0; + + obj = bpf_object__open_file(filename, NULL); + err = libbpf_get_error(obj); + if (err < 0) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return err; + } + + /* load BPF program */ + err = bpf_object__load(obj); + if (err < 0) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + return err; + } + + bpf_object__for_each_program(prog, obj) { + links[cnt] = bpf_program__attach(prog); + err = libbpf_get_error(links[cnt]); + if (err < 0) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[cnt] = NULL; + return err; + } + cnt++; + } + + return err; +} + +static void unload_progs(void) +{ + while (cnt) + bpf_link__destroy(links[--cnt]); + + bpf_object__close(obj); +} + +int main(int argc, char **argv) +{ + int num_cpu = sysconf(_SC_NPROCESSORS_ONLN); + int test_flags = ~0; + char filename[256]; + int err = 0; + + + if (argc > 1) + test_flags = atoi(argv[1]) ? : test_flags; + if (argc > 2) + num_cpu = atoi(argv[2]) ? : num_cpu; + + if (test_flags & 0x3) { + printf("BASE\n"); + run_perf_test(num_cpu, test_flags); + } + + if (test_flags & 0xC) { + snprintf(filename, sizeof(filename), + "%s_kprobe_kern.o", argv[0]); + + printf("w/KPROBE\n"); + err = load_progs(filename); + if (!err) + run_perf_test(num_cpu, test_flags >> 2); + + unload_progs(); + } + + if (test_flags & 0x30) { + snprintf(filename, sizeof(filename), + "%s_tp_kern.o", argv[0]); + printf("w/TRACEPOINT\n"); + err = load_progs(filename); + if (!err) + run_perf_test(num_cpu, test_flags >> 4); + + unload_progs(); + } + + if (test_flags & 0xC0) { + snprintf(filename, sizeof(filename), + "%s_raw_tp_kern.o", argv[0]); + printf("w/RAW_TRACEPOINT\n"); + err = load_progs(filename); + if (!err) + run_perf_test(num_cpu, test_flags >> 6); + + unload_progs(); + } + + return err; +} |