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 
24 static struct bpf_link *links[2];
25 static struct bpf_object *obj;
26 static int cnt;
27 
28 static __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 
36 static 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 
60 static 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 
84 static 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 
98 static 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 
121 static 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 
154 static void unload_progs(void)
155 {
156 	while (cnt)
157 		bpf_link__destroy(links[--cnt]);
158 
159 	bpf_object__close(obj);
160 }
161 
162 int 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 }
216