2 * Copyright (C) 2015 Davidlohr Bueso.
5 /* For the CLR_() macros */
9 #include "../util/stat.h"
10 #include <subcmd/parse-options.h>
11 #include <linux/compiler.h>
12 #include <linux/kernel.h>
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;
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"),
50 static const char * const bench_futex_lock_pi_usage[] = {
51 "perf bench futex requeue <options>",
55 static void print_summary(void)
57 unsigned long avg = avg_stats(&throughput_stats);
58 double stddev = stddev_stats(&throughput_stats);
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);
65 static void toggle_done(int sig __maybe_unused,
66 siginfo_t *info __maybe_unused,
67 void *uc __maybe_unused)
69 /* inform all threads that we're done for the day */
71 gettimeofday(&end, NULL);
72 timersub(&end, &start, &runtime);
75 static void *workerfn(void *arg)
77 struct worker *w = (struct worker *) arg;
78 unsigned long ops = w->ops;
80 pthread_mutex_lock(&thread_lock);
82 if (!threads_starting)
83 pthread_cond_signal(&thread_parent);
84 pthread_cond_wait(&thread_worker, &thread_lock);
85 pthread_mutex_unlock(&thread_lock);
90 ret = futex_lock_pi(w->futex, NULL, futex_flag);
92 if (ret) { /* handle lock acquisition */
94 warn("thread %d: Could not lock pi-lock for %p (%d)",
95 w->tid, w->futex, ret);
103 ret = futex_unlock_pi(w->futex, futex_flag);
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 */
114 static void create_threads(struct worker *w, pthread_attr_t thread_attr)
119 threads_starting = nthreads;
121 for (i = 0; i < nthreads; i++) {
125 worker[i].futex = calloc(1, sizeof(u_int32_t));
126 if (!worker[i].futex)
127 err(EXIT_FAILURE, "calloc");
129 worker[i].futex = &global_futex;
132 CPU_SET(i % ncpus, &cpu);
134 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
135 err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
137 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i]))
138 err(EXIT_FAILURE, "pthread_create");
142 int bench_futex_lock_pi(int argc, const char **argv,
143 const char *prefix __maybe_unused)
147 struct sigaction act;
148 pthread_attr_t thread_attr;
150 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0);
154 ncpus = sysconf(_SC_NPROCESSORS_ONLN);
155 nsecs = futexbench_sanitize_numeric(nsecs);
157 sigfillset(&act.sa_mask);
158 act.sa_sigaction = toggle_done;
159 sigaction(SIGINT, &act, NULL);
164 nthreads = futexbench_sanitize_numeric(nthreads);
166 worker = calloc(nthreads, sizeof(*worker));
168 err(EXIT_FAILURE, "calloc");
171 futex_flag = FUTEX_PRIVATE_FLAG;
173 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n",
174 getpid(), nthreads, nsecs);
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);
181 threads_starting = nthreads;
182 pthread_attr_init(&thread_attr);
183 gettimeofday(&start, NULL);
185 create_threads(worker, thread_attr);
186 pthread_attr_destroy(&thread_attr);
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);
195 toggle_done(0, NULL, NULL);
197 for (i = 0; i < nthreads; i++) {
198 ret = pthread_join(worker[i].thread, NULL);
200 err(EXIT_FAILURE, "pthread_join");
203 /* cleanup & report results */
204 pthread_cond_destroy(&thread_parent);
205 pthread_cond_destroy(&thread_worker);
206 pthread_mutex_destroy(&thread_lock);
208 for (i = 0; i < nthreads; i++) {
209 unsigned long t = worker[i].ops/runtime.tv_sec;
211 update_stats(&throughput_stats, t);
213 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n",
214 worker[i].tid, worker[i].futex, t);
217 free(worker[i].futex);
225 usage_with_options(bench_futex_lock_pi_usage, options);