xref: /linux/samples/bpf/test_overhead_user.c (revision e04946f54cd99fa1bd92e22f4540720d76d88058)
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 <sys/socket.h>
15 #include <arpa/inet.h>
16 #include <stdlib.h>
17 #include <signal.h>
18 #include <linux/bpf.h>
19 #include <string.h>
20 #include <time.h>
21 #include <bpf/bpf.h>
22 #include <bpf/libbpf.h>
23 
24 #define MAX_CNT 1000000
25 #define DUMMY_IP "127.0.0.1"
26 #define DUMMY_PORT 80
27 
28 static struct bpf_link *links[2];
29 static struct bpf_object *obj;
30 static int cnt;
31 
32 static __u64 time_get_ns(void)
33 {
34 	struct timespec ts;
35 
36 	clock_gettime(CLOCK_MONOTONIC, &ts);
37 	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
38 }
39 
40 static void test_task_rename(int cpu)
41 {
42 	char buf[] = "test\n";
43 	__u64 start_time;
44 	int i, fd;
45 
46 	fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
47 	if (fd < 0) {
48 		printf("couldn't open /proc\n");
49 		exit(1);
50 	}
51 	start_time = time_get_ns();
52 	for (i = 0; i < MAX_CNT; i++) {
53 		if (write(fd, buf, sizeof(buf)) < 0) {
54 			printf("task rename failed: %s\n", strerror(errno));
55 			close(fd);
56 			return;
57 		}
58 	}
59 	printf("task_rename:%d: %lld events per sec\n",
60 	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
61 	close(fd);
62 }
63 
64 static void test_fib_table_lookup(int cpu)
65 {
66 	struct sockaddr_in addr;
67 	char buf[] = "test\n";
68 	__u64 start_time;
69 	int i, fd;
70 
71 	fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
72 	if (fd < 0) {
73 		printf("couldn't open socket\n");
74 		exit(1);
75 	}
76 	memset((char *)&addr, 0, sizeof(addr));
77 	addr.sin_addr.s_addr = inet_addr(DUMMY_IP);
78 	addr.sin_port = htons(DUMMY_PORT);
79 	addr.sin_family = AF_INET;
80 	start_time = time_get_ns();
81 	for (i = 0; i < MAX_CNT; i++) {
82 		if (sendto(fd, buf, strlen(buf), 0,
83 			   (struct sockaddr *)&addr, sizeof(addr)) < 0) {
84 			printf("failed to start ping: %s\n", strerror(errno));
85 			close(fd);
86 			return;
87 		}
88 	}
89 	printf("fib_table_lookup:%d: %lld events per sec\n",
90 	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
91 	close(fd);
92 }
93 
94 static void loop(int cpu, int flags)
95 {
96 	cpu_set_t cpuset;
97 
98 	CPU_ZERO(&cpuset);
99 	CPU_SET(cpu, &cpuset);
100 	sched_setaffinity(0, sizeof(cpuset), &cpuset);
101 
102 	if (flags & 1)
103 		test_task_rename(cpu);
104 	if (flags & 2)
105 		test_fib_table_lookup(cpu);
106 }
107 
108 static void run_perf_test(int tasks, int flags)
109 {
110 	pid_t pid[tasks];
111 	int i;
112 
113 	for (i = 0; i < tasks; i++) {
114 		pid[i] = fork();
115 		if (pid[i] == 0) {
116 			loop(i, flags);
117 			exit(0);
118 		} else if (pid[i] == -1) {
119 			printf("couldn't spawn #%d process\n", i);
120 			exit(1);
121 		}
122 	}
123 	for (i = 0; i < tasks; i++) {
124 		int status;
125 
126 		assert(waitpid(pid[i], &status, 0) == pid[i]);
127 		assert(status == 0);
128 	}
129 }
130 
131 static int load_progs(char *filename)
132 {
133 	struct bpf_program *prog;
134 	int err = 0;
135 
136 	obj = bpf_object__open_file(filename, NULL);
137 	err = libbpf_get_error(obj);
138 	if (err < 0) {
139 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
140 		return err;
141 	}
142 
143 	/* load BPF program */
144 	err = bpf_object__load(obj);
145 	if (err < 0) {
146 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
147 		return err;
148 	}
149 
150 	bpf_object__for_each_program(prog, obj) {
151 		links[cnt] = bpf_program__attach(prog);
152 		err = libbpf_get_error(links[cnt]);
153 		if (err < 0) {
154 			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
155 			links[cnt] = NULL;
156 			return err;
157 		}
158 		cnt++;
159 	}
160 
161 	return err;
162 }
163 
164 static void unload_progs(void)
165 {
166 	while (cnt)
167 		bpf_link__destroy(links[--cnt]);
168 
169 	bpf_object__close(obj);
170 }
171 
172 int main(int argc, char **argv)
173 {
174 	int num_cpu = sysconf(_SC_NPROCESSORS_ONLN);
175 	int test_flags = ~0;
176 	char filename[256];
177 	int err = 0;
178 
179 
180 	if (argc > 1)
181 		test_flags = atoi(argv[1]) ? : test_flags;
182 	if (argc > 2)
183 		num_cpu = atoi(argv[2]) ? : num_cpu;
184 
185 	if (test_flags & 0x3) {
186 		printf("BASE\n");
187 		run_perf_test(num_cpu, test_flags);
188 	}
189 
190 	if (test_flags & 0xC) {
191 		snprintf(filename, sizeof(filename),
192 			 "%s_kprobe.bpf.o", argv[0]);
193 
194 		printf("w/KPROBE\n");
195 		err = load_progs(filename);
196 		if (!err)
197 			run_perf_test(num_cpu, test_flags >> 2);
198 
199 		unload_progs();
200 	}
201 
202 	if (test_flags & 0x30) {
203 		snprintf(filename, sizeof(filename),
204 			 "%s_tp.bpf.o", argv[0]);
205 		printf("w/TRACEPOINT\n");
206 		err = load_progs(filename);
207 		if (!err)
208 			run_perf_test(num_cpu, test_flags >> 4);
209 
210 		unload_progs();
211 	}
212 
213 	if (test_flags & 0xC0) {
214 		snprintf(filename, sizeof(filename),
215 			 "%s_raw_tp.bpf.o", argv[0]);
216 		printf("w/RAW_TRACEPOINT\n");
217 		err = load_progs(filename);
218 		if (!err)
219 			run_perf_test(num_cpu, test_flags >> 6);
220 
221 		unload_progs();
222 	}
223 
224 	return err;
225 }
226