1 /* 2 * 3 * sched-pipe.c 4 * 5 * pipe: Benchmark for pipe() 6 * 7 * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com> 8 * http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c 9 * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> 10 */ 11 #include "../perf.h" 12 #include "../util/util.h" 13 #include <subcmd/parse-options.h> 14 #include "../builtin.h" 15 #include "bench.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 <assert.h> 25 #include <sys/time.h> 26 #include <sys/types.h> 27 #include <sys/syscall.h> 28 #include <linux/time64.h> 29 30 #include <pthread.h> 31 32 struct thread_data { 33 int nr; 34 int pipe_read; 35 int pipe_write; 36 pthread_t pthread; 37 }; 38 39 #define LOOPS_DEFAULT 1000000 40 static int loops = LOOPS_DEFAULT; 41 42 /* Use processes by default: */ 43 static bool threaded; 44 45 static const struct option options[] = { 46 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"), 47 OPT_BOOLEAN('T', "threaded", &threaded, "Specify threads/process based task setup"), 48 OPT_END() 49 }; 50 51 static const char * const bench_sched_pipe_usage[] = { 52 "perf bench sched pipe <options>", 53 NULL 54 }; 55 56 static void *worker_thread(void *__tdata) 57 { 58 struct thread_data *td = __tdata; 59 int m = 0, i; 60 int ret; 61 62 for (i = 0; i < loops; i++) { 63 if (!td->nr) { 64 ret = read(td->pipe_read, &m, sizeof(int)); 65 BUG_ON(ret != sizeof(int)); 66 ret = write(td->pipe_write, &m, sizeof(int)); 67 BUG_ON(ret != sizeof(int)); 68 } else { 69 ret = write(td->pipe_write, &m, sizeof(int)); 70 BUG_ON(ret != sizeof(int)); 71 ret = read(td->pipe_read, &m, sizeof(int)); 72 BUG_ON(ret != sizeof(int)); 73 } 74 } 75 76 return NULL; 77 } 78 79 int bench_sched_pipe(int argc, const char **argv) 80 { 81 struct thread_data threads[2], *td; 82 int pipe_1[2], pipe_2[2]; 83 struct timeval start, stop, diff; 84 unsigned long long result_usec = 0; 85 int nr_threads = 2; 86 int t; 87 88 /* 89 * why does "ret" exist? 90 * discarding returned value of read(), write() 91 * causes error in building environment for perf 92 */ 93 int __maybe_unused ret, wait_stat; 94 pid_t pid, retpid __maybe_unused; 95 96 argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0); 97 98 BUG_ON(pipe(pipe_1)); 99 BUG_ON(pipe(pipe_2)); 100 101 gettimeofday(&start, NULL); 102 103 for (t = 0; t < nr_threads; t++) { 104 td = threads + t; 105 106 td->nr = t; 107 108 if (t == 0) { 109 td->pipe_read = pipe_1[0]; 110 td->pipe_write = pipe_2[1]; 111 } else { 112 td->pipe_write = pipe_1[1]; 113 td->pipe_read = pipe_2[0]; 114 } 115 } 116 117 118 if (threaded) { 119 120 for (t = 0; t < nr_threads; t++) { 121 td = threads + t; 122 123 ret = pthread_create(&td->pthread, NULL, worker_thread, td); 124 BUG_ON(ret); 125 } 126 127 for (t = 0; t < nr_threads; t++) { 128 td = threads + t; 129 130 ret = pthread_join(td->pthread, NULL); 131 BUG_ON(ret); 132 } 133 134 } else { 135 pid = fork(); 136 assert(pid >= 0); 137 138 if (!pid) { 139 worker_thread(threads + 0); 140 exit(0); 141 } else { 142 worker_thread(threads + 1); 143 } 144 145 retpid = waitpid(pid, &wait_stat, 0); 146 assert((retpid == pid) && WIFEXITED(wait_stat)); 147 } 148 149 gettimeofday(&stop, NULL); 150 timersub(&stop, &start, &diff); 151 152 switch (bench_format) { 153 case BENCH_FORMAT_DEFAULT: 154 printf("# Executed %d pipe operations between two %s\n\n", 155 loops, threaded ? "threads" : "processes"); 156 157 result_usec = diff.tv_sec * USEC_PER_SEC; 158 result_usec += diff.tv_usec; 159 160 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time", 161 diff.tv_sec, 162 (unsigned long) (diff.tv_usec / USEC_PER_MSEC)); 163 164 printf(" %14lf usecs/op\n", 165 (double)result_usec / (double)loops); 166 printf(" %14d ops/sec\n", 167 (int)((double)loops / 168 ((double)result_usec / (double)USEC_PER_SEC))); 169 break; 170 171 case BENCH_FORMAT_SIMPLE: 172 printf("%lu.%03lu\n", 173 diff.tv_sec, 174 (unsigned long) (diff.tv_usec / USEC_PER_MSEC)); 175 break; 176 177 default: 178 /* reaching here is something disaster */ 179 fprintf(stderr, "Unknown format:%d\n", bench_format); 180 exit(1); 181 break; 182 } 183 184 return 0; 185 } 186