1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2016 Facebook
  3 */
  4#define _GNU_SOURCE
  5#include <sched.h>
  6#include <errno.h>
  7#include <stdio.h>
  8#include <sys/types.h>
  9#include <asm/unistd.h>
 10#include <fcntl.h>
 11#include <unistd.h>
 12#include <assert.h>
 13#include <sys/wait.h>
 14#include <stdlib.h>
 15#include <signal.h>
 16#include <linux/bpf.h>
 17#include <string.h>
 18#include <time.h>
 19#include <bpf/bpf.h>
 20#include <bpf/libbpf.h>
 21
 22#define MAX_CNT 1000000
 23
 24static struct bpf_link *links[2];
 25static struct bpf_object *obj;
 26static int cnt;
 27
 28static __u64 time_get_ns(void)
 29{
 30	struct timespec ts;
 31
 32	clock_gettime(CLOCK_MONOTONIC, &ts);
 33	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
 34}
 35
 36static void test_task_rename(int cpu)
 37{
 38	__u64 start_time;
 39	char buf[] = "test\n";
 40	int i, fd;
 41
 42	fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
 43	if (fd < 0) {
 44		printf("couldn't open /proc\n");
 45		exit(1);
 46	}
 47	start_time = time_get_ns();
 48	for (i = 0; i < MAX_CNT; i++) {
 49		if (write(fd, buf, sizeof(buf)) < 0) {
 50			printf("task rename failed: %s\n", strerror(errno));
 51			close(fd);
 52			return;
 53		}
 54	}
 55	printf("task_rename:%d: %lld events per sec\n",
 56	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
 57	close(fd);
 58}
 59
 60static void test_urandom_read(int cpu)
 61{
 62	__u64 start_time;
 63	char buf[4];
 64	int i, fd;
 65
 66	fd = open("/dev/urandom", O_RDONLY);
 67	if (fd < 0) {
 68		printf("couldn't open /dev/urandom\n");
 69		exit(1);
 70	}
 71	start_time = time_get_ns();
 72	for (i = 0; i < MAX_CNT; i++) {
 73		if (read(fd, buf, sizeof(buf)) < 0) {
 74			printf("failed to read from /dev/urandom: %s\n", strerror(errno));
 75			close(fd);
 76			return;
 77		}
 78	}
 79	printf("urandom_read:%d: %lld events per sec\n",
 80	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
 81	close(fd);
 82}
 83
 84static void loop(int cpu, int flags)
 85{
 86	cpu_set_t cpuset;
 87
 88	CPU_ZERO(&cpuset);
 89	CPU_SET(cpu, &cpuset);
 90	sched_setaffinity(0, sizeof(cpuset), &cpuset);
 91
 92	if (flags & 1)
 93		test_task_rename(cpu);
 94	if (flags & 2)
 95		test_urandom_read(cpu);
 96}
 97
 98static void run_perf_test(int tasks, int flags)
 99{
100	pid_t pid[tasks];
101	int i;
102
103	for (i = 0; i < tasks; i++) {
104		pid[i] = fork();
105		if (pid[i] == 0) {
106			loop(i, flags);
107			exit(0);
108		} else if (pid[i] == -1) {
109			printf("couldn't spawn #%d process\n", i);
110			exit(1);
111		}
112	}
113	for (i = 0; i < tasks; i++) {
114		int status;
115
116		assert(waitpid(pid[i], &status, 0) == pid[i]);
117		assert(status == 0);
118	}
119}
120
121static int load_progs(char *filename)
122{
123	struct bpf_program *prog;
124	int err = 0;
125
126	obj = bpf_object__open_file(filename, NULL);
127	err = libbpf_get_error(obj);
128	if (err < 0) {
129		fprintf(stderr, "ERROR: opening BPF object file failed\n");
130		return err;
131	}
132
133	/* load BPF program */
134	err = bpf_object__load(obj);
135	if (err < 0) {
136		fprintf(stderr, "ERROR: loading BPF object file failed\n");
137		return err;
138	}
139
140	bpf_object__for_each_program(prog, obj) {
141		links[cnt] = bpf_program__attach(prog);
142		err = libbpf_get_error(links[cnt]);
143		if (err < 0) {
144			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
145			links[cnt] = NULL;
146			return err;
147		}
148		cnt++;
149	}
150
151	return err;
152}
153
154static void unload_progs(void)
155{
156	while (cnt)
157		bpf_link__destroy(links[--cnt]);
158
159	bpf_object__close(obj);
160}
161
162int main(int argc, char **argv)
163{
164	int num_cpu = sysconf(_SC_NPROCESSORS_ONLN);
165	int test_flags = ~0;
166	char filename[256];
167	int err = 0;
168
169
170	if (argc > 1)
171		test_flags = atoi(argv[1]) ? : test_flags;
172	if (argc > 2)
173		num_cpu = atoi(argv[2]) ? : num_cpu;
174
175	if (test_flags & 0x3) {
176		printf("BASE\n");
177		run_perf_test(num_cpu, test_flags);
178	}
179
180	if (test_flags & 0xC) {
181		snprintf(filename, sizeof(filename),
182			 "%s_kprobe_kern.o", argv[0]);
183
184		printf("w/KPROBE\n");
185		err = load_progs(filename);
186		if (!err)
187			run_perf_test(num_cpu, test_flags >> 2);
188
189		unload_progs();
190	}
191
192	if (test_flags & 0x30) {
193		snprintf(filename, sizeof(filename),
194			 "%s_tp_kern.o", argv[0]);
195		printf("w/TRACEPOINT\n");
196		err = load_progs(filename);
197		if (!err)
198			run_perf_test(num_cpu, test_flags >> 4);
199
200		unload_progs();
201	}
202
203	if (test_flags & 0xC0) {
204		snprintf(filename, sizeof(filename),
205			 "%s_raw_tp_kern.o", argv[0]);
206		printf("w/RAW_TRACEPOINT\n");
207		err = load_progs(filename);
208		if (!err)
209			run_perf_test(num_cpu, test_flags >> 6);
210
211		unload_progs();
212	}
213
214	return err;
215}