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
28static struct bpf_link *links[2];
29static struct bpf_object *obj;
30static int cnt;
31
32static __u64 time_get_ns(void)
33{
34 struct timespec ts;
35
36 clock_gettime(CLOCK_MONOTONIC, tp: &ts);
37 return ts.tv_sec * 1000000000ull + ts.tv_nsec;
38}
39
40static void test_task_rename(int cpu)
41{
42 char buf[] = "test\n";
43 __u64 start_time;
44 int i, fd;
45
46 fd = open(file: "/proc/self/comm", O_WRONLY|O_TRUNC);
47 if (fd < 0) {
48 printf(format: "couldn't open /proc\n");
49 exit(status: 1);
50 }
51 start_time = time_get_ns();
52 for (i = 0; i < MAX_CNT; i++) {
53 if (write(fd: fd, buf: buf, n: sizeof(buf)) < 0) {
54 printf(format: "task rename failed: %s\n", strerror(errno));
55 close(fd: fd);
56 return;
57 }
58 }
59 printf(format: "task_rename:%d: %lld events per sec\n",
60 cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
61 close(fd: fd);
62}
63
64static 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(format: "couldn't open socket\n");
74 exit(status: 1);
75 }
76 memset(s: (char *)&addr, c: 0, n: 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: fd, buf: buf, n: strlen(s: buf), flags: 0,
83 addr: (struct sockaddr *)&addr, addr_len: sizeof(addr)) < 0) {
84 printf(format: "failed to start ping: %s\n", strerror(errno));
85 close(fd: fd);
86 return;
87 }
88 }
89 printf(format: "fib_table_lookup:%d: %lld events per sec\n",
90 cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
91 close(fd: fd);
92}
93
94static 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(pid: 0, cpusetsize: sizeof(cpuset), cpuset: &cpuset);
101
102 if (flags & 1)
103 test_task_rename(cpu);
104 if (flags & 2)
105 test_fib_table_lookup(cpu);
106}
107
108static 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(cpu: i, flags);
117 exit(status: 0);
118 } else if (pid[i] == -1) {
119 printf(format: "couldn't spawn #%d process\n", i);
120 exit(status: 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
131static 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, format: "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, format: "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, format: "ERROR: bpf_program__attach failed\n");
155 links[cnt] = NULL;
156 return err;
157 }
158 cnt++;
159 }
160
161 return err;
162}
163
164static void unload_progs(void)
165{
166 while (cnt)
167 bpf_link__destroy(links[--cnt]);
168
169 bpf_object__close(obj);
170}
171
172int 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(nptr: argv[1]) ? : test_flags;
182 if (argc > 2)
183 num_cpu = atoi(nptr: argv[2]) ? : num_cpu;
184
185 if (test_flags & 0x3) {
186 printf(format: "BASE\n");
187 run_perf_test(tasks: num_cpu, flags: test_flags);
188 }
189
190 if (test_flags & 0xC) {
191 snprintf(s: filename, maxlen: sizeof(filename),
192 format: "%s_kprobe.bpf.o", argv[0]);
193
194 printf(format: "w/KPROBE\n");
195 err = load_progs(filename);
196 if (!err)
197 run_perf_test(tasks: num_cpu, flags: test_flags >> 2);
198
199 unload_progs();
200 }
201
202 if (test_flags & 0x30) {
203 snprintf(s: filename, maxlen: sizeof(filename),
204 format: "%s_tp.bpf.o", argv[0]);
205 printf(format: "w/TRACEPOINT\n");
206 err = load_progs(filename);
207 if (!err)
208 run_perf_test(tasks: num_cpu, flags: test_flags >> 4);
209
210 unload_progs();
211 }
212
213 if (test_flags & 0xC0) {
214 snprintf(s: filename, maxlen: sizeof(filename),
215 format: "%s_raw_tp.bpf.o", argv[0]);
216 printf(format: "w/RAW_TRACEPOINT\n");
217 err = load_progs(filename);
218 if (!err)
219 run_perf_test(tasks: num_cpu, flags: test_flags >> 6);
220
221 unload_progs();
222 }
223
224 return err;
225}
226

source code of linux/samples/bpf/test_overhead_user.c