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5
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
21struct worker {
22 int tid;
23 u_int32_t *futex;
24 pthread_t thread;
25 unsigned long ops;
26};
27
28static u_int32_t global_futex = 0;
29static struct worker *worker;
30static unsigned int nsecs = 10;
31static bool silent = false, multi = false;
32static bool done = false, fshared = false;
33static unsigned int ncpus, nthreads = 0;
34static int futex_flag = 0;
35struct timeval start, end, runtime;
36static pthread_mutex_t thread_lock;
37static unsigned int threads_starting;
38static struct stats throughput_stats;
39static pthread_cond_t thread_parent, thread_worker;
40
41static 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
50static const char * const bench_futex_lock_pi_usage[] = {
51 "perf bench futex lock-pi <options>",
52 NULL
53};
54
55static 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
65static void toggle_done(int sig __maybe_unused,
66 siginfo_t *info __maybe_unused,
67 void *uc __maybe_unused)
68{
69
70 done = true;
71 gettimeofday(&end, NULL);
72 timersub(&end, &start, &runtime);
73}
74
75static 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) {
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++;
108 } while (!done);
109
110 w->ops = ops;
111 return NULL;
112}
113
114static 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
142int 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
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;
224err:
225 usage_with_options(bench_futex_lock_pi_usage, options);
226 exit(EXIT_FAILURE);
227}
228
