1 /* 2 * 3 * sched-pipe.c 4 * 5 * pipe: Benchmark for pipe() 6 * 7 * Based on pipe-test-1m.c by Ingo Molnar <mingo (at) redhat.com> 8 * http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c 9 * Ported to perf by Hitoshi Mitake <mitake (at) dcl.info.waseda.ac.jp> 10 * 11 */ 12 13 #include "../perf.h" 14 #include "../util/util.h" 15 #include "../util/parse-options.h" 16 #include "../builtin.h" 17 #include "bench.h" 18 19 #include <unistd.h> 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <signal.h> 23 #include <sys/wait.h> 24 #include <linux/unistd.h> 25 #include <string.h> 26 #include <errno.h> 27 #include <assert.h> 28 #include <sys/time.h> 29 #include <sys/types.h> 30 31 #define LOOPS_DEFAULT 1000000 32 static int loops = LOOPS_DEFAULT; 33 34 static const struct option options[] = { 35 OPT_INTEGER('l', "loop", &loops, 36 "Specify number of loops"), 37 OPT_END() 38 }; 39 40 static const char * const bench_sched_pipe_usage[] = { 41 "perf bench sched pipe <options>", 42 NULL 43 }; 44 45 int bench_sched_pipe(int argc, const char **argv, 46 const char *prefix __used) 47 { 48 /* ANDROID_CHANGE_BEGIN */ 49 #ifndef __BIONIC__ 50 int pipe_1[2], pipe_2[2]; 51 int m = 0, i; 52 struct timeval start, stop, diff; 53 unsigned long long result_usec = 0; 54 55 /* 56 * why does "ret" exist? 57 * discarding returned value of read(), write() 58 * causes error in building environment for perf 59 */ 60 int __used ret, wait_stat; 61 pid_t pid, retpid; 62 63 argc = parse_options(argc, argv, options, 64 bench_sched_pipe_usage, 0); 65 66 assert(!pipe(pipe_1)); 67 assert(!pipe(pipe_2)); 68 69 pid = fork(); 70 assert(pid >= 0); 71 72 gettimeofday(&start, NULL); 73 74 if (!pid) { 75 for (i = 0; i < loops; i++) { 76 ret = read(pipe_1[0], &m, sizeof(int)); 77 ret = write(pipe_2[1], &m, sizeof(int)); 78 } 79 } else { 80 for (i = 0; i < loops; i++) { 81 ret = write(pipe_1[1], &m, sizeof(int)); 82 ret = read(pipe_2[0], &m, sizeof(int)); 83 } 84 } 85 86 gettimeofday(&stop, NULL); 87 timersub(&stop, &start, &diff); 88 89 if (pid) { 90 retpid = waitpid(pid, &wait_stat, 0); 91 assert((retpid == pid) && WIFEXITED(wait_stat)); 92 } else { 93 exit(0); 94 } 95 96 switch (bench_format) { 97 case BENCH_FORMAT_DEFAULT: 98 printf("# Executed %d pipe operations between two tasks\n\n", 99 loops); 100 101 result_usec = diff.tv_sec * 1000000; 102 result_usec += diff.tv_usec; 103 104 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time", 105 diff.tv_sec, 106 (unsigned long) (diff.tv_usec/1000)); 107 108 printf(" %14lf usecs/op\n", 109 (double)result_usec / (double)loops); 110 printf(" %14d ops/sec\n", 111 (int)((double)loops / 112 ((double)result_usec / (double)1000000))); 113 break; 114 115 case BENCH_FORMAT_SIMPLE: 116 printf("%lu.%03lu\n", 117 diff.tv_sec, 118 (unsigned long) (diff.tv_usec / 1000)); 119 break; 120 121 default: 122 /* reaching here is something disaster */ 123 fprintf(stderr, "Unknown format:%d\n", bench_format); 124 exit(1); 125 break; 126 } 127 #endif 128 /* ANDROID_CHANGE_END */ 129 130 return 0; 131 } 132
