1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2015 Davidlohr Bueso. 4 */ 5 6 /* For the CLR_() macros */ 7 #include <string.h> 8 #include <pthread.h> 9 10 #include <signal.h> 11 #include "../util/stat.h" 12 #include <subcmd/parse-options.h> 13 #include <linux/compiler.h> 14 #include <linux/kernel.h> 15 #include <errno.h> 16 #include "bench.h" 17 #include "futex.h" 18 19 #include <err.h> 20 #include <stdlib.h> 21 #include <sys/time.h> 22 23 struct worker { 24 int tid; 25 u_int32_t *futex; 26 pthread_t thread; 27 unsigned long ops; 28 }; 29 30 static u_int32_t global_futex = 0; 31 static struct worker *worker; 32 static unsigned int nsecs = 10; 33 static bool silent = false, multi = false; 34 static bool done = false, fshared = false; 35 static unsigned int ncpus, nthreads = 0; 36 static int futex_flag = 0; 37 struct timeval start, end, runtime; 38 static pthread_mutex_t thread_lock; 39 static unsigned int threads_starting; 40 static struct stats throughput_stats; 41 static pthread_cond_t thread_parent, thread_worker; 42 43 static const struct option options[] = { 44 OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"), 45 OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"), 46 OPT_BOOLEAN( 'M', "multi", &multi, "Use multiple futexes"), 47 OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"), 48 OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"), 49 OPT_END() 50 }; 51 52 static const char * const bench_futex_lock_pi_usage[] = { 53 "perf bench futex lock-pi <options>", 54 NULL 55 }; 56 57 static void print_summary(void) 58 { 59 unsigned long avg = avg_stats(&throughput_stats); 60 double stddev = stddev_stats(&throughput_stats); 61 62 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n", 63 !silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg), 64 (int) runtime.tv_sec); 65 } 66 67 static void toggle_done(int sig __maybe_unused, 68 siginfo_t *info __maybe_unused, 69 void *uc __maybe_unused) 70 { 71 /* inform all threads that we're done for the day */ 72 done = true; 73 gettimeofday(&end, NULL); 74 timersub(&end, &start, &runtime); 75 } 76 77 static void *workerfn(void *arg) 78 { 79 struct worker *w = (struct worker *) arg; 80 unsigned long ops = w->ops; 81 82 pthread_mutex_lock(&thread_lock); 83 threads_starting--; 84 if (!threads_starting) 85 pthread_cond_signal(&thread_parent); 86 pthread_cond_wait(&thread_worker, &thread_lock); 87 pthread_mutex_unlock(&thread_lock); 88 89 do { 90 int ret; 91 again: 92 ret = futex_lock_pi(w->futex, NULL, futex_flag); 93 94 if (ret) { /* handle lock acquisition */ 95 if (!silent) 96 warn("thread %d: Could not lock pi-lock for %p (%d)", 97 w->tid, w->futex, ret); 98 if (done) 99 break; 100 101 goto again; 102 } 103 104 usleep(1); 105 ret = futex_unlock_pi(w->futex, futex_flag); 106 if (ret && !silent) 107 warn("thread %d: Could not unlock pi-lock for %p (%d)", 108 w->tid, w->futex, ret); 109 ops++; /* account for thread's share of work */ 110 } while (!done); 111 112 w->ops = ops; 113 return NULL; 114 } 115 116 static void create_threads(struct worker *w, pthread_attr_t thread_attr) 117 { 118 cpu_set_t cpu; 119 unsigned int i; 120 121 threads_starting = nthreads; 122 123 for (i = 0; i < nthreads; i++) { 124 worker[i].tid = i; 125 126 if (multi) { 127 worker[i].futex = calloc(1, sizeof(u_int32_t)); 128 if (!worker[i].futex) 129 err(EXIT_FAILURE, "calloc"); 130 } else 131 worker[i].futex = &global_futex; 132 133 CPU_ZERO(&cpu); 134 CPU_SET(i % ncpus, &cpu); 135 136 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu)) 137 err(EXIT_FAILURE, "pthread_attr_setaffinity_np"); 138 139 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) 140 err(EXIT_FAILURE, "pthread_create"); 141 } 142 } 143 144 int bench_futex_lock_pi(int argc, const char **argv) 145 { 146 int ret = 0; 147 unsigned int i; 148 struct sigaction act; 149 pthread_attr_t thread_attr; 150 151 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0); 152 if (argc) 153 goto err; 154 155 ncpus = sysconf(_SC_NPROCESSORS_ONLN); 156 157 sigfillset(&act.sa_mask); 158 act.sa_sigaction = toggle_done; 159 sigaction(SIGINT, &act, NULL); 160 161 if (!nthreads) 162 nthreads = ncpus; 163 164 worker = calloc(nthreads, sizeof(*worker)); 165 if (!worker) 166 err(EXIT_FAILURE, "calloc"); 167 168 if (!fshared) 169 futex_flag = FUTEX_PRIVATE_FLAG; 170 171 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n", 172 getpid(), nthreads, nsecs); 173 174 init_stats(&throughput_stats); 175 pthread_mutex_init(&thread_lock, NULL); 176 pthread_cond_init(&thread_parent, NULL); 177 pthread_cond_init(&thread_worker, NULL); 178 179 threads_starting = nthreads; 180 pthread_attr_init(&thread_attr); 181 gettimeofday(&start, NULL); 182 183 create_threads(worker, thread_attr); 184 pthread_attr_destroy(&thread_attr); 185 186 pthread_mutex_lock(&thread_lock); 187 while (threads_starting) 188 pthread_cond_wait(&thread_parent, &thread_lock); 189 pthread_cond_broadcast(&thread_worker); 190 pthread_mutex_unlock(&thread_lock); 191 192 sleep(nsecs); 193 toggle_done(0, NULL, NULL); 194 195 for (i = 0; i < nthreads; i++) { 196 ret = pthread_join(worker[i].thread, NULL); 197 if (ret) 198 err(EXIT_FAILURE, "pthread_join"); 199 } 200 201 /* cleanup & report results */ 202 pthread_cond_destroy(&thread_parent); 203 pthread_cond_destroy(&thread_worker); 204 pthread_mutex_destroy(&thread_lock); 205 206 for (i = 0; i < nthreads; i++) { 207 unsigned long t = worker[i].ops/runtime.tv_sec; 208 209 update_stats(&throughput_stats, t); 210 if (!silent) 211 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n", 212 worker[i].tid, worker[i].futex, t); 213 214 if (multi) 215 free(worker[i].futex); 216 } 217 218 print_summary(); 219 220 free(worker); 221 return ret; 222 err: 223 usage_with_options(bench_futex_lock_pi_usage, options); 224 exit(EXIT_FAILURE); 225 } 226