308 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 *4 * sched-pipe.c5 *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.c10 * 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 33struct 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 100000042static int loops = LOOPS_DEFAULT;43 44/* Use processes by default: */45static bool threaded;46 47static char *cgrp_names[2];48static struct cgroup *cgrps[2];49 50static 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 78out:79 free(p);80 return ret;81}82 83static 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 92static const char * const bench_sched_pipe_usage[] = {93 "perf bench sched pipe <options>",94 NULL95};96 97static 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 else118 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 else127 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 145err: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 162static void exit_cgroup(int nr)163{164 cgroup__put(cgrps[nr]);165 free(cgrp_names[nr]);166}167 168static 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 197int 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 perf211 */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