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 lock-pi <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 unsigned long ops = w->ops; 79 80 pthread_mutex_lock(&thread_lock); 81 threads_starting--; 82 if (!threads_starting) 83 pthread_cond_signal(&thread_parent); 84 pthread_cond_wait(&thread_worker, &thread_lock); 85 pthread_mutex_unlock(&thread_lock); 86 87 do { 88 int ret; 89 again: 90 ret = futex_lock_pi(w->futex, NULL, futex_flag); 91 92 if (ret) { /* handle lock acquisition */ 93 if (!silent) 94 warn("thread %d: Could not lock pi-lock for %p (%d)", 95 w->tid, w->futex, ret); 96 if (done) 97 break; 98 99 goto again; 100 } 101 102 usleep(1); 103 ret = futex_unlock_pi(w->futex, futex_flag); 104 if (ret && !silent) 105 warn("thread %d: Could not unlock pi-lock for %p (%d)", 106 w->tid, w->futex, ret); 107 ops++; /* account for thread's share of work */ 108 } while (!done); 109 110 w->ops = ops; 111 return NULL; 112 } 113 114 static void create_threads(struct worker *w, pthread_attr_t thread_attr) 115 { 116 cpu_set_t cpu; 117 unsigned int i; 118 119 threads_starting = nthreads; 120 121 for (i = 0; i < nthreads; i++) { 122 worker[i].tid = i; 123 124 if (multi) { 125 worker[i].futex = calloc(1, sizeof(u_int32_t)); 126 if (!worker[i].futex) 127 err(EXIT_FAILURE, "calloc"); 128 } else 129 worker[i].futex = &global_futex; 130 131 CPU_ZERO(&cpu); 132 CPU_SET(i % ncpus, &cpu); 133 134 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu)) 135 err(EXIT_FAILURE, "pthread_attr_setaffinity_np"); 136 137 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) 138 err(EXIT_FAILURE, "pthread_create"); 139 } 140 } 141 142 int bench_futex_lock_pi(int argc, const char **argv, 143 const char *prefix __maybe_unused) 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 nsecs = futexbench_sanitize_numeric(nsecs); 156 157 sigfillset(&act.sa_mask); 158 act.sa_sigaction = toggle_done; 159 sigaction(SIGINT, &act, NULL); 160 161 if (!nthreads) 162 nthreads = ncpus; 163 else 164 nthreads = futexbench_sanitize_numeric(nthreads); 165 166 worker = calloc(nthreads, sizeof(*worker)); 167 if (!worker) 168 err(EXIT_FAILURE, "calloc"); 169 170 if (!fshared) 171 futex_flag = FUTEX_PRIVATE_FLAG; 172 173 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n", 174 getpid(), nthreads, nsecs); 175 176 init_stats(&throughput_stats); 177 pthread_mutex_init(&thread_lock, NULL); 178 pthread_cond_init(&thread_parent, NULL); 179 pthread_cond_init(&thread_worker, NULL); 180 181 threads_starting = nthreads; 182 pthread_attr_init(&thread_attr); 183 gettimeofday(&start, NULL); 184 185 create_threads(worker, thread_attr); 186 pthread_attr_destroy(&thread_attr); 187 188 pthread_mutex_lock(&thread_lock); 189 while (threads_starting) 190 pthread_cond_wait(&thread_parent, &thread_lock); 191 pthread_cond_broadcast(&thread_worker); 192 pthread_mutex_unlock(&thread_lock); 193 194 sleep(nsecs); 195 toggle_done(0, NULL, NULL); 196 197 for (i = 0; i < nthreads; i++) { 198 ret = pthread_join(worker[i].thread, NULL); 199 if (ret) 200 err(EXIT_FAILURE, "pthread_join"); 201 } 202 203 /* cleanup & report results */ 204 pthread_cond_destroy(&thread_parent); 205 pthread_cond_destroy(&thread_worker); 206 pthread_mutex_destroy(&thread_lock); 207 208 for (i = 0; i < nthreads; i++) { 209 unsigned long t = worker[i].ops/runtime.tv_sec; 210 211 update_stats(&throughput_stats, t); 212 if (!silent) 213 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n", 214 worker[i].tid, worker[i].futex, t); 215 216 if (multi) 217 free(worker[i].futex); 218 } 219 220 print_summary(); 221 222 free(worker); 223 return ret; 224 err: 225 usage_with_options(bench_futex_lock_pi_usage, options); 226 exit(EXIT_FAILURE); 227 } 228