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 29 #include <pthread.h> 30 31 struct thread_data { 32 int nr; 33 int pipe_read; 34 int pipe_write; 35 pthread_t pthread; 36 }; 37 38 #define LOOPS_DEFAULT 1000000 39 static int loops = LOOPS_DEFAULT; 40 41 /* Use processes by default: */ 42 static bool threaded; 43 44 static const struct option options[] = { 45 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"), 46 OPT_BOOLEAN('T', "threaded", &threaded, "Specify threads/process based task setup"), 47 OPT_END() 48 }; 49 50 static const char * const bench_sched_pipe_usage[] = { 51 "perf bench sched pipe <options>", 52 NULL 53 }; 54 55 static void *worker_thread(void *__tdata) 56 { 57 struct thread_data *td = __tdata; 58 int m = 0, i; 59 int ret; 60 61 for (i = 0; i < loops; i++) { 62 if (!td->nr) { 63 ret = read(td->pipe_read, &m, sizeof(int)); 64 BUG_ON(ret != sizeof(int)); 65 ret = write(td->pipe_write, &m, sizeof(int)); 66 BUG_ON(ret != sizeof(int)); 67 } else { 68 ret = write(td->pipe_write, &m, sizeof(int)); 69 BUG_ON(ret != sizeof(int)); 70 ret = read(td->pipe_read, &m, sizeof(int)); 71 BUG_ON(ret != sizeof(int)); 72 } 73 } 74 75 return NULL; 76 } 77 78 int bench_sched_pipe(int argc, const char **argv, const char *prefix __maybe_unused) 79 { 80 struct thread_data threads[2], *td; 81 int pipe_1[2], pipe_2[2]; 82 struct timeval start, stop, diff; 83 unsigned long long result_usec = 0; 84 int nr_threads = 2; 85 int t; 86 87 /* 88 * why does "ret" exist? 89 * discarding returned value of read(), write() 90 * causes error in building environment for perf 91 */ 92 int __maybe_unused ret, wait_stat; 93 pid_t pid, retpid __maybe_unused; 94 95 argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0); 96 97 BUG_ON(pipe(pipe_1)); 98 BUG_ON(pipe(pipe_2)); 99 100 gettimeofday(&start, NULL); 101 102 for (t = 0; t < nr_threads; t++) { 103 td = threads + t; 104 105 td->nr = t; 106 107 if (t == 0) { 108 td->pipe_read = pipe_1[0]; 109 td->pipe_write = pipe_2[1]; 110 } else { 111 td->pipe_write = pipe_1[1]; 112 td->pipe_read = pipe_2[0]; 113 } 114 } 115 116 117 if (threaded) { 118 119 for (t = 0; t < nr_threads; t++) { 120 td = threads + t; 121 122 ret = pthread_create(&td->pthread, NULL, worker_thread, td); 123 BUG_ON(ret); 124 } 125 126 for (t = 0; t < nr_threads; t++) { 127 td = threads + t; 128 129 ret = pthread_join(td->pthread, NULL); 130 BUG_ON(ret); 131 } 132 133 } else { 134 pid = fork(); 135 assert(pid >= 0); 136 137 if (!pid) { 138 worker_thread(threads + 0); 139 exit(0); 140 } else { 141 worker_thread(threads + 1); 142 } 143 144 retpid = waitpid(pid, &wait_stat, 0); 145 assert((retpid == pid) && WIFEXITED(wait_stat)); 146 } 147 148 gettimeofday(&stop, NULL); 149 timersub(&stop, &start, &diff); 150 151 switch (bench_format) { 152 case BENCH_FORMAT_DEFAULT: 153 printf("# Executed %d pipe operations between two %s\n\n", 154 loops, threaded ? "threads" : "processes"); 155 156 result_usec = diff.tv_sec * 1000000; 157 result_usec += diff.tv_usec; 158 159 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time", 160 diff.tv_sec, 161 (unsigned long) (diff.tv_usec/1000)); 162 163 printf(" %14lf usecs/op\n", 164 (double)result_usec / (double)loops); 165 printf(" %14d ops/sec\n", 166 (int)((double)loops / 167 ((double)result_usec / (double)1000000))); 168 break; 169 170 case BENCH_FORMAT_SIMPLE: 171 printf("%lu.%03lu\n", 172 diff.tv_sec, 173 (unsigned long) (diff.tv_usec / 1000)); 174 break; 175 176 default: 177 /* reaching here is something disaster */ 178 fprintf(stderr, "Unknown format:%d\n", bench_format); 179 exit(1); 180 break; 181 } 182 183 return 0; 184 } 185