1 /* 2 * Copyright (C) 2015 Davidlohr Bueso. 3 */ 4 5 /* For the CLR_() macros */ 6 #include <pthread.h> 7 8 #include <signal.h> 9 #include "../util/stat.h" 10 #include <subcmd/parse-options.h> 11 #include <linux/compiler.h> 12 #include <linux/kernel.h> 13 #include <errno.h> 14 #include "bench.h" 15 #include "futex.h" 16 17 #include <err.h> 18 #include <stdlib.h> 19 #include <sys/time.h> 20 21 struct worker { 22 int tid; 23 u_int32_t *futex; 24 pthread_t thread; 25 unsigned long ops; 26 }; 27 28 static u_int32_t global_futex = 0; 29 static struct worker *worker; 30 static unsigned int nsecs = 10; 31 static bool silent = false, multi = false; 32 static bool done = false, fshared = false; 33 static unsigned int ncpus, nthreads = 0; 34 static int futex_flag = 0; 35 struct timeval start, end, runtime; 36 static pthread_mutex_t thread_lock; 37 static unsigned int threads_starting; 38 static struct stats throughput_stats; 39 static pthread_cond_t thread_parent, thread_worker; 40 41 static const struct option options[] = { 42 OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"), 43 OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"), 44 OPT_BOOLEAN( 'M', "multi", &multi, "Use multiple futexes"), 45 OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"), 46 OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"), 47 OPT_END() 48 }; 49 50 static const char * const bench_futex_lock_pi_usage[] = { 51 "perf bench futex requeue <options>", 52 NULL 53 }; 54 55 static void print_summary(void) 56 { 57 unsigned long avg = avg_stats(&throughput_stats); 58 double stddev = stddev_stats(&throughput_stats); 59 60 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n", 61 !silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg), 62 (int) runtime.tv_sec); 63 } 64 65 static void toggle_done(int sig __maybe_unused, 66 siginfo_t *info __maybe_unused, 67 void *uc __maybe_unused) 68 { 69 /* inform all threads that we're done for the day */ 70 done = true; 71 gettimeofday(&end, NULL); 72 timersub(&end, &start, &runtime); 73 } 74 75 static void *workerfn(void *arg) 76 { 77 struct worker *w = (struct worker *) arg; 78 79 pthread_mutex_lock(&thread_lock); 80 threads_starting--; 81 if (!threads_starting) 82 pthread_cond_signal(&thread_parent); 83 pthread_cond_wait(&thread_worker, &thread_lock); 84 pthread_mutex_unlock(&thread_lock); 85 86 do { 87 int ret; 88 again: 89 ret = futex_lock_pi(w->futex, NULL, futex_flag); 90 91 if (ret) { /* handle lock acquisition */ 92 if (!silent) 93 warn("thread %d: Could not lock pi-lock for %p (%d)", 94 w->tid, w->futex, ret); 95 if (done) 96 break; 97 98 goto again; 99 } 100 101 usleep(1); 102 ret = futex_unlock_pi(w->futex, futex_flag); 103 if (ret && !silent) 104 warn("thread %d: Could not unlock pi-lock for %p (%d)", 105 w->tid, w->futex, ret); 106 w->ops++; /* account for thread's share of work */ 107 } while (!done); 108 109 return NULL; 110 } 111 112 static void create_threads(struct worker *w, pthread_attr_t thread_attr) 113 { 114 cpu_set_t cpu; 115 unsigned int i; 116 117 threads_starting = nthreads; 118 119 for (i = 0; i < nthreads; i++) { 120 worker[i].tid = i; 121 122 if (multi) { 123 worker[i].futex = calloc(1, sizeof(u_int32_t)); 124 if (!worker[i].futex) 125 err(EXIT_FAILURE, "calloc"); 126 } else 127 worker[i].futex = &global_futex; 128 129 CPU_ZERO(&cpu); 130 CPU_SET(i % ncpus, &cpu); 131 132 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu)) 133 err(EXIT_FAILURE, "pthread_attr_setaffinity_np"); 134 135 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) 136 err(EXIT_FAILURE, "pthread_create"); 137 } 138 } 139 140 int bench_futex_lock_pi(int argc, const char **argv, 141 const char *prefix __maybe_unused) 142 { 143 int ret = 0; 144 unsigned int i; 145 struct sigaction act; 146 pthread_attr_t thread_attr; 147 148 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0); 149 if (argc) 150 goto err; 151 152 ncpus = sysconf(_SC_NPROCESSORS_ONLN); 153 154 sigfillset(&act.sa_mask); 155 act.sa_sigaction = toggle_done; 156 sigaction(SIGINT, &act, NULL); 157 158 if (!nthreads) 159 nthreads = ncpus; 160 161 worker = calloc(nthreads, sizeof(*worker)); 162 if (!worker) 163 err(EXIT_FAILURE, "calloc"); 164 165 if (!fshared) 166 futex_flag = FUTEX_PRIVATE_FLAG; 167 168 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n", 169 getpid(), nthreads, nsecs); 170 171 init_stats(&throughput_stats); 172 pthread_mutex_init(&thread_lock, NULL); 173 pthread_cond_init(&thread_parent, NULL); 174 pthread_cond_init(&thread_worker, NULL); 175 176 threads_starting = nthreads; 177 pthread_attr_init(&thread_attr); 178 gettimeofday(&start, NULL); 179 180 create_threads(worker, thread_attr); 181 pthread_attr_destroy(&thread_attr); 182 183 pthread_mutex_lock(&thread_lock); 184 while (threads_starting) 185 pthread_cond_wait(&thread_parent, &thread_lock); 186 pthread_cond_broadcast(&thread_worker); 187 pthread_mutex_unlock(&thread_lock); 188 189 sleep(nsecs); 190 toggle_done(0, NULL, NULL); 191 192 for (i = 0; i < nthreads; i++) { 193 ret = pthread_join(worker[i].thread, NULL); 194 if (ret) 195 err(EXIT_FAILURE, "pthread_join"); 196 } 197 198 /* cleanup & report results */ 199 pthread_cond_destroy(&thread_parent); 200 pthread_cond_destroy(&thread_worker); 201 pthread_mutex_destroy(&thread_lock); 202 203 for (i = 0; i < nthreads; i++) { 204 unsigned long t = worker[i].ops/runtime.tv_sec; 205 206 update_stats(&throughput_stats, t); 207 if (!silent) 208 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n", 209 worker[i].tid, worker[i].futex, t); 210 211 if (multi) 212 free(worker[i].futex); 213 } 214 215 print_summary(); 216 217 free(worker); 218 return ret; 219 err: 220 usage_with_options(bench_futex_lock_pi_usage, options); 221 exit(EXIT_FAILURE); 222 } 223