1 /* 2 * Copyright (C) 2015 Davidlohr Bueso. 3 */ 4 5 /* For the CLR_() macros */ 6 #include <string.h> 7 #include <pthread.h> 8 9 #include <signal.h> 10 #include "../util/stat.h" 11 #include <subcmd/parse-options.h> 12 #include <linux/compiler.h> 13 #include <linux/kernel.h> 14 #include <errno.h> 15 #include "bench.h" 16 #include "futex.h" 17 18 #include <err.h> 19 #include <stdlib.h> 20 #include <sys/time.h> 21 22 struct worker { 23 int tid; 24 u_int32_t *futex; 25 pthread_t thread; 26 unsigned long ops; 27 }; 28 29 static u_int32_t global_futex = 0; 30 static struct worker *worker; 31 static unsigned int nsecs = 10; 32 static bool silent = false, multi = false; 33 static bool done = false, fshared = false; 34 static unsigned int ncpus, nthreads = 0; 35 static int futex_flag = 0; 36 struct timeval start, end, runtime; 37 static pthread_mutex_t thread_lock; 38 static unsigned int threads_starting; 39 static struct stats throughput_stats; 40 static pthread_cond_t thread_parent, thread_worker; 41 42 static const struct option options[] = { 43 OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"), 44 OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"), 45 OPT_BOOLEAN( 'M', "multi", &multi, "Use multiple futexes"), 46 OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"), 47 OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"), 48 OPT_END() 49 }; 50 51 static const char * const bench_futex_lock_pi_usage[] = { 52 "perf bench futex lock-pi <options>", 53 NULL 54 }; 55 56 static void print_summary(void) 57 { 58 unsigned long avg = avg_stats(&throughput_stats); 59 double stddev = stddev_stats(&throughput_stats); 60 61 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n", 62 !silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg), 63 (int) runtime.tv_sec); 64 } 65 66 static void toggle_done(int sig __maybe_unused, 67 siginfo_t *info __maybe_unused, 68 void *uc __maybe_unused) 69 { 70 /* inform all threads that we're done for the day */ 71 done = true; 72 gettimeofday(&end, NULL); 73 timersub(&end, &start, &runtime); 74 } 75 76 static void *workerfn(void *arg) 77 { 78 struct worker *w = (struct worker *) arg; 79 unsigned long ops = w->ops; 80 81 pthread_mutex_lock(&thread_lock); 82 threads_starting--; 83 if (!threads_starting) 84 pthread_cond_signal(&thread_parent); 85 pthread_cond_wait(&thread_worker, &thread_lock); 86 pthread_mutex_unlock(&thread_lock); 87 88 do { 89 int ret; 90 again: 91 ret = futex_lock_pi(w->futex, NULL, futex_flag); 92 93 if (ret) { /* handle lock acquisition */ 94 if (!silent) 95 warn("thread %d: Could not lock pi-lock for %p (%d)", 96 w->tid, w->futex, ret); 97 if (done) 98 break; 99 100 goto again; 101 } 102 103 usleep(1); 104 ret = futex_unlock_pi(w->futex, futex_flag); 105 if (ret && !silent) 106 warn("thread %d: Could not unlock pi-lock for %p (%d)", 107 w->tid, w->futex, ret); 108 ops++; /* account for thread's share of work */ 109 } while (!done); 110 111 w->ops = ops; 112 return NULL; 113 } 114 115 static void create_threads(struct worker *w, pthread_attr_t thread_attr) 116 { 117 cpu_set_t cpu; 118 unsigned int i; 119 120 threads_starting = nthreads; 121 122 for (i = 0; i < nthreads; i++) { 123 worker[i].tid = i; 124 125 if (multi) { 126 worker[i].futex = calloc(1, sizeof(u_int32_t)); 127 if (!worker[i].futex) 128 err(EXIT_FAILURE, "calloc"); 129 } else 130 worker[i].futex = &global_futex; 131 132 CPU_ZERO(&cpu); 133 CPU_SET(i % ncpus, &cpu); 134 135 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu)) 136 err(EXIT_FAILURE, "pthread_attr_setaffinity_np"); 137 138 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) 139 err(EXIT_FAILURE, "pthread_create"); 140 } 141 } 142 143 int bench_futex_lock_pi(int argc, const char **argv) 144 { 145 int ret = 0; 146 unsigned int i; 147 struct sigaction act; 148 pthread_attr_t thread_attr; 149 150 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0); 151 if (argc) 152 goto err; 153 154 ncpus = sysconf(_SC_NPROCESSORS_ONLN); 155 156 sigfillset(&act.sa_mask); 157 act.sa_sigaction = toggle_done; 158 sigaction(SIGINT, &act, NULL); 159 160 if (!nthreads) 161 nthreads = ncpus; 162 163 worker = calloc(nthreads, sizeof(*worker)); 164 if (!worker) 165 err(EXIT_FAILURE, "calloc"); 166 167 if (!fshared) 168 futex_flag = FUTEX_PRIVATE_FLAG; 169 170 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n", 171 getpid(), nthreads, nsecs); 172 173 init_stats(&throughput_stats); 174 pthread_mutex_init(&thread_lock, NULL); 175 pthread_cond_init(&thread_parent, NULL); 176 pthread_cond_init(&thread_worker, NULL); 177 178 threads_starting = nthreads; 179 pthread_attr_init(&thread_attr); 180 gettimeofday(&start, NULL); 181 182 create_threads(worker, thread_attr); 183 pthread_attr_destroy(&thread_attr); 184 185 pthread_mutex_lock(&thread_lock); 186 while (threads_starting) 187 pthread_cond_wait(&thread_parent, &thread_lock); 188 pthread_cond_broadcast(&thread_worker); 189 pthread_mutex_unlock(&thread_lock); 190 191 sleep(nsecs); 192 toggle_done(0, NULL, NULL); 193 194 for (i = 0; i < nthreads; i++) { 195 ret = pthread_join(worker[i].thread, NULL); 196 if (ret) 197 err(EXIT_FAILURE, "pthread_join"); 198 } 199 200 /* cleanup & report results */ 201 pthread_cond_destroy(&thread_parent); 202 pthread_cond_destroy(&thread_worker); 203 pthread_mutex_destroy(&thread_lock); 204 205 for (i = 0; i < nthreads; i++) { 206 unsigned long t = worker[i].ops/runtime.tv_sec; 207 208 update_stats(&throughput_stats, t); 209 if (!silent) 210 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n", 211 worker[i].tid, worker[i].futex, t); 212 213 if (multi) 214 free(worker[i].futex); 215 } 216 217 print_summary(); 218 219 free(worker); 220 return ret; 221 err: 222 usage_with_options(bench_futex_lock_pi_usage, options); 223 exit(EXIT_FAILURE); 224 } 225