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 <linux/zalloc.h> 16 #include <errno.h> 17 #include <internal/cpumap.h> 18 #include <perf/cpumap.h> 19 #include "bench.h" 20 #include "futex.h" 21 22 #include <err.h> 23 #include <stdlib.h> 24 #include <sys/time.h> 25 26 struct worker { 27 int tid; 28 u_int32_t *futex; 29 pthread_t thread; 30 unsigned long ops; 31 }; 32 33 static u_int32_t global_futex = 0; 34 static struct worker *worker; 35 static unsigned int nsecs = 10; 36 static bool silent = false, multi = false; 37 static bool done = false, fshared = false; 38 static unsigned int nthreads = 0; 39 static int futex_flag = 0; 40 struct timeval start, end, runtime; 41 static pthread_mutex_t thread_lock; 42 static unsigned int threads_starting; 43 static struct stats throughput_stats; 44 static pthread_cond_t thread_parent, thread_worker; 45 46 static const struct option options[] = { 47 OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"), 48 OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"), 49 OPT_BOOLEAN( 'M', "multi", &multi, "Use multiple futexes"), 50 OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"), 51 OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"), 52 OPT_END() 53 }; 54 55 static const char * const bench_futex_lock_pi_usage[] = { 56 "perf bench futex lock-pi <options>", 57 NULL 58 }; 59 60 static void print_summary(void) 61 { 62 unsigned long avg = avg_stats(&throughput_stats); 63 double stddev = stddev_stats(&throughput_stats); 64 65 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n", 66 !silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg), 67 (int) runtime.tv_sec); 68 } 69 70 static void toggle_done(int sig __maybe_unused, 71 siginfo_t *info __maybe_unused, 72 void *uc __maybe_unused) 73 { 74 /* inform all threads that we're done for the day */ 75 done = true; 76 gettimeofday(&end, NULL); 77 timersub(&end, &start, &runtime); 78 } 79 80 static void *workerfn(void *arg) 81 { 82 struct worker *w = (struct worker *) arg; 83 unsigned long ops = w->ops; 84 85 pthread_mutex_lock(&thread_lock); 86 threads_starting--; 87 if (!threads_starting) 88 pthread_cond_signal(&thread_parent); 89 pthread_cond_wait(&thread_worker, &thread_lock); 90 pthread_mutex_unlock(&thread_lock); 91 92 do { 93 int ret; 94 again: 95 ret = futex_lock_pi(w->futex, NULL, futex_flag); 96 97 if (ret) { /* handle lock acquisition */ 98 if (!silent) 99 warn("thread %d: Could not lock pi-lock for %p (%d)", 100 w->tid, w->futex, ret); 101 if (done) 102 break; 103 104 goto again; 105 } 106 107 usleep(1); 108 ret = futex_unlock_pi(w->futex, futex_flag); 109 if (ret && !silent) 110 warn("thread %d: Could not unlock pi-lock for %p (%d)", 111 w->tid, w->futex, ret); 112 ops++; /* account for thread's share of work */ 113 } while (!done); 114 115 w->ops = ops; 116 return NULL; 117 } 118 119 static void create_threads(struct worker *w, pthread_attr_t thread_attr, 120 struct perf_cpu_map *cpu) 121 { 122 cpu_set_t cpuset; 123 unsigned int i; 124 125 threads_starting = nthreads; 126 127 for (i = 0; i < nthreads; i++) { 128 worker[i].tid = i; 129 130 if (multi) { 131 worker[i].futex = calloc(1, sizeof(u_int32_t)); 132 if (!worker[i].futex) 133 err(EXIT_FAILURE, "calloc"); 134 } else 135 worker[i].futex = &global_futex; 136 137 CPU_ZERO(&cpuset); 138 CPU_SET(cpu->map[i % cpu->nr], &cpuset); 139 140 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset)) 141 err(EXIT_FAILURE, "pthread_attr_setaffinity_np"); 142 143 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) 144 err(EXIT_FAILURE, "pthread_create"); 145 } 146 } 147 148 int bench_futex_lock_pi(int argc, const char **argv) 149 { 150 int ret = 0; 151 unsigned int i; 152 struct sigaction act; 153 pthread_attr_t thread_attr; 154 struct perf_cpu_map *cpu; 155 156 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0); 157 if (argc) 158 goto err; 159 160 cpu = perf_cpu_map__new(NULL); 161 if (!cpu) 162 err(EXIT_FAILURE, "calloc"); 163 164 sigfillset(&act.sa_mask); 165 act.sa_sigaction = toggle_done; 166 sigaction(SIGINT, &act, NULL); 167 168 if (!nthreads) 169 nthreads = cpu->nr; 170 171 worker = calloc(nthreads, sizeof(*worker)); 172 if (!worker) 173 err(EXIT_FAILURE, "calloc"); 174 175 if (!fshared) 176 futex_flag = FUTEX_PRIVATE_FLAG; 177 178 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n", 179 getpid(), nthreads, nsecs); 180 181 init_stats(&throughput_stats); 182 pthread_mutex_init(&thread_lock, NULL); 183 pthread_cond_init(&thread_parent, NULL); 184 pthread_cond_init(&thread_worker, NULL); 185 186 threads_starting = nthreads; 187 pthread_attr_init(&thread_attr); 188 gettimeofday(&start, NULL); 189 190 create_threads(worker, thread_attr, cpu); 191 pthread_attr_destroy(&thread_attr); 192 193 pthread_mutex_lock(&thread_lock); 194 while (threads_starting) 195 pthread_cond_wait(&thread_parent, &thread_lock); 196 pthread_cond_broadcast(&thread_worker); 197 pthread_mutex_unlock(&thread_lock); 198 199 sleep(nsecs); 200 toggle_done(0, NULL, NULL); 201 202 for (i = 0; i < nthreads; i++) { 203 ret = pthread_join(worker[i].thread, NULL); 204 if (ret) 205 err(EXIT_FAILURE, "pthread_join"); 206 } 207 208 /* cleanup & report results */ 209 pthread_cond_destroy(&thread_parent); 210 pthread_cond_destroy(&thread_worker); 211 pthread_mutex_destroy(&thread_lock); 212 213 for (i = 0; i < nthreads; i++) { 214 unsigned long t = worker[i].ops/runtime.tv_sec; 215 216 update_stats(&throughput_stats, t); 217 if (!silent) 218 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n", 219 worker[i].tid, worker[i].futex, t); 220 221 if (multi) 222 zfree(&worker[i].futex); 223 } 224 225 print_summary(); 226 227 free(worker); 228 return ret; 229 err: 230 usage_with_options(bench_futex_lock_pi_usage, options); 231 exit(EXIT_FAILURE); 232 } 233