1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 *
4 * sched-pipe.c
5 *
6 * pipe: Benchmark for pipe()
7 *
8 * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
9 * http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
10 * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
11 */
12 #include <subcmd/parse-options.h>
13 #include <api/fs/fs.h>
14 #include "bench.h"
15 #include "util/cgroup.h"
16
17 #include <unistd.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <signal.h>
21 #include <sys/wait.h>
22 #include <string.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <assert.h>
26 #include <sys/time.h>
27 #include <sys/types.h>
28 #include <sys/syscall.h>
29 #include <linux/time64.h>
30
31 #include <pthread.h>
32
33 struct thread_data {
34 int nr;
35 int pipe_read;
36 int pipe_write;
37 bool cgroup_failed;
38 pthread_t pthread;
39 };
40
41 #define LOOPS_DEFAULT 1000000
42 static int loops = LOOPS_DEFAULT;
43
44 /* Use processes by default: */
45 static bool threaded;
46
47 static char *cgrp_names[2];
48 static struct cgroup *cgrps[2];
49
50 static int parse_two_cgroups(const struct option *opt __maybe_unused,
51 const char *str, int unset __maybe_unused)
52 {
53 char *p = strdup(str);
54 char *q;
55 int ret = -1;
56
57 if (p == NULL) {
58 fprintf(stderr, "memory allocation failure\n");
59 return -1;
60 }
61
62 q = strchr(p, ',');
63 if (q == NULL) {
64 fprintf(stderr, "it should have two cgroup names: %s\n", p);
65 goto out;
66 }
67 *q = '\0';
68
69 cgrp_names[0] = strdup(p);
70 cgrp_names[1] = strdup(q + 1);
71
72 if (cgrp_names[0] == NULL || cgrp_names[1] == NULL) {
73 fprintf(stderr, "memory allocation failure\n");
74 goto out;
75 }
76 ret = 0;
77
78 out:
79 free(p);
80 return ret;
81 }
82
83 static const struct option options[] = {
84 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
85 OPT_BOOLEAN('T', "threaded", &threaded, "Specify threads/process based task setup"),
86 OPT_CALLBACK('G', "cgroups", NULL, "SEND,RECV",
87 "Put sender and receivers in given cgroups",
88 parse_two_cgroups),
89 OPT_END()
90 };
91
92 static const char * const bench_sched_pipe_usage[] = {
93 "perf bench sched pipe <options>",
94 NULL
95 };
96
97 static int enter_cgroup(int nr)
98 {
99 char buf[32];
100 int fd, len, ret;
101 int saved_errno;
102 struct cgroup *cgrp;
103 pid_t pid;
104
105 if (cgrp_names[nr] == NULL)
106 return 0;
107
108 if (cgrps[nr] == NULL) {
109 cgrps[nr] = cgroup__new(cgrp_names[nr], /*do_open=*/true);
110 if (cgrps[nr] == NULL)
111 goto err;
112 }
113 cgrp = cgrps[nr];
114
115 if (threaded)
116 pid = syscall(__NR_gettid);
117 else
118 pid = getpid();
119
120 snprintf(buf, sizeof(buf), "%d\n", pid);
121 len = strlen(buf);
122
123 /* try cgroup v2 interface first */
124 if (threaded)
125 fd = openat(cgrp->fd, "cgroup.threads", O_WRONLY);
126 else
127 fd = openat(cgrp->fd, "cgroup.procs", O_WRONLY);
128
129 /* try cgroup v1 if failed */
130 if (fd < 0 && errno == ENOENT)
131 fd = openat(cgrp->fd, "tasks", O_WRONLY);
132
133 if (fd < 0)
134 goto err;
135
136 ret = write(fd, buf, len);
137 close(fd);
138
139 if (ret != len) {
140 printf("Cannot enter to cgroup: %s\n", cgrp->name);
141 return -1;
142 }
143 return 0;
144
145 err:
146 saved_errno = errno;
147 printf("Failed to open cgroup file in %s\n", cgrp_names[nr]);
148
149 if (saved_errno == ENOENT) {
150 char mnt[PATH_MAX];
151
152 if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event") == 0)
153 printf(" Hint: create the cgroup first, like 'mkdir %s/%s'\n",
154 mnt, cgrp_names[nr]);
155 } else if (saved_errno == EACCES && geteuid() > 0) {
156 printf(" Hint: try to run as root\n");
157 }
158
159 return -1;
160 }
161
162 static void exit_cgroup(int nr)
163 {
164 cgroup__put(cgrps[nr]);
165 free(cgrp_names[nr]);
166 }
167
168 static void *worker_thread(void *__tdata)
169 {
170 struct thread_data *td = __tdata;
171 int m = 0, i;
172 int ret;
173
174 ret = enter_cgroup(td->nr);
175 if (ret < 0) {
176 td->cgroup_failed = true;
177 return NULL;
178 }
179
180 for (i = 0; i < loops; i++) {
181 if (!td->nr) {
182 ret = read(td->pipe_read, &m, sizeof(int));
183 BUG_ON(ret != sizeof(int));
184 ret = write(td->pipe_write, &m, sizeof(int));
185 BUG_ON(ret != sizeof(int));
186 } else {
187 ret = write(td->pipe_write, &m, sizeof(int));
188 BUG_ON(ret != sizeof(int));
189 ret = read(td->pipe_read, &m, sizeof(int));
190 BUG_ON(ret != sizeof(int));
191 }
192 }
193
194 return NULL;
195 }
196
197 int bench_sched_pipe(int argc, const char **argv)
198 {
199 struct thread_data threads[2] = {};
200 struct thread_data *td;
201 int pipe_1[2], pipe_2[2];
202 struct timeval start, stop, diff;
203 unsigned long long result_usec = 0;
204 int nr_threads = 2;
205 int t;
206
207 /*
208 * why does "ret" exist?
209 * discarding returned value of read(), write()
210 * causes error in building environment for perf
211 */
212 int __maybe_unused ret, wait_stat;
213 pid_t pid, retpid __maybe_unused;
214
215 argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0);
216
217 BUG_ON(pipe(pipe_1));
218 BUG_ON(pipe(pipe_2));
219
220 gettimeofday(&start, NULL);
221
222 for (t = 0; t < nr_threads; t++) {
223 td = threads + t;
224
225 td->nr = t;
226
227 if (t == 0) {
228 td->pipe_read = pipe_1[0];
229 td->pipe_write = pipe_2[1];
230 } else {
231 td->pipe_write = pipe_1[1];
232 td->pipe_read = pipe_2[0];
233 }
234 }
235
236 if (threaded) {
237 for (t = 0; t < nr_threads; t++) {
238 td = threads + t;
239
240 ret = pthread_create(&td->pthread, NULL, worker_thread, td);
241 BUG_ON(ret);
242 }
243
244 for (t = 0; t < nr_threads; t++) {
245 td = threads + t;
246
247 ret = pthread_join(td->pthread, NULL);
248 BUG_ON(ret);
249 }
250 } else {
251 pid = fork();
252 assert(pid >= 0);
253
254 if (!pid) {
255 worker_thread(threads + 0);
256 exit(0);
257 } else {
258 worker_thread(threads + 1);
259 }
260
261 retpid = waitpid(pid, &wait_stat, 0);
262 assert((retpid == pid) && WIFEXITED(wait_stat));
263 }
264
265 gettimeofday(&stop, NULL);
266 timersub(&stop, &start, &diff);
267
268 exit_cgroup(0);
269 exit_cgroup(1);
270
271 if (threads[0].cgroup_failed || threads[1].cgroup_failed)
272 return 0;
273
274 switch (bench_format) {
275 case BENCH_FORMAT_DEFAULT:
276 printf("# Executed %d pipe operations between two %s\n\n",
277 loops, threaded ? "threads" : "processes");
278
279 result_usec = diff.tv_sec * USEC_PER_SEC;
280 result_usec += diff.tv_usec;
281
282 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
283 (unsigned long) diff.tv_sec,
284 (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
285
286 printf(" %14lf usecs/op\n",
287 (double)result_usec / (double)loops);
288 printf(" %14d ops/sec\n",
289 (int)((double)loops /
290 ((double)result_usec / (double)USEC_PER_SEC)));
291 break;
292
293 case BENCH_FORMAT_SIMPLE:
294 printf("%lu.%03lu\n",
295 (unsigned long) diff.tv_sec,
296 (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
297 break;
298
299 default:
300 /* reaching here is something disaster */
301 fprintf(stderr, "Unknown format:%d\n", bench_format);
302 exit(1);
303 break;
304 }
305
306 return 0;
307 }
308
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