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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 <perf/cpumap.h>
18#include "bench.h"
19#include "futex.h"
20
21#include <err.h>
22#include <stdlib.h>
23#include <sys/time.h>
24#include <sys/mman.h>
25
26struct worker {
27 int tid;
28 u_int32_t *futex;
29 pthread_t thread;
30 unsigned long ops;
31};
32
33static u_int32_t global_futex = 0;
34static struct worker *worker;
35static bool done = false;
36static int futex_flag = 0;
37static pthread_mutex_t thread_lock;
38static unsigned int threads_starting;
39static struct stats throughput_stats;
40static pthread_cond_t thread_parent, thread_worker;
41
42static struct bench_futex_parameters params = {
43 .runtime = 10,
44};
45
46static const struct option options[] = {
47 OPT_UINTEGER('t', "threads", ¶ms.nthreads, "Specify amount of threads"),
48 OPT_UINTEGER('r', "runtime", ¶ms.runtime, "Specify runtime (in seconds)"),
49 OPT_BOOLEAN( 'M', "multi", ¶ms.multi, "Use multiple futexes"),
50 OPT_BOOLEAN( 's', "silent", ¶ms.silent, "Silent mode: do not display data/details"),
51 OPT_BOOLEAN( 'S', "shared", ¶ms.fshared, "Use shared futexes instead of private ones"),
52 OPT_BOOLEAN( 'm', "mlockall", ¶ms.mlockall, "Lock all current and future memory"),
53 OPT_END()
54};
55
56static const char * const bench_futex_lock_pi_usage[] = {
57 "perf bench futex lock-pi <options>",
58 NULL
59};
60
61static void print_summary(void)
62{
63 unsigned long avg = avg_stats(&throughput_stats);
64 double stddev = stddev_stats(&throughput_stats);
65
66 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
67 !params.silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
68 (int)bench__runtime.tv_sec);
69}
70
71static void toggle_done(int sig __maybe_unused,
72 siginfo_t *info __maybe_unused,
73 void *uc __maybe_unused)
74{
75
76 done = true;
77 gettimeofday(&bench__end, NULL);
78 timersub(&bench__end, &bench__start, &bench__runtime);
79}
80
81static void *workerfn(void *arg)
82{
83 struct worker *w = (struct worker *) arg;
84 unsigned long ops = w->ops;
85
86 pthread_mutex_lock(&thread_lock);
87 threads_starting--;
88 if (!threads_starting)
89 pthread_cond_signal(&thread_parent);
90 pthread_cond_wait(&thread_worker, &thread_lock);
91 pthread_mutex_unlock(&thread_lock);
92
93 do {
94 int ret;
95 again:
96 ret = futex_lock_pi(w->futex, NULL, futex_flag);
97
98 if (ret) {
99 if (!params.silent)
100 warn("thread %d: Could not lock pi-lock for %p (%d)",
101 w->tid, w->futex, ret);
102 if (done)
103 break;
104
105 goto again;
106 }
107
108 usleep(1);
109 ret = futex_unlock_pi(w->futex, futex_flag);
110 if (ret && !params.silent)
111 warn("thread %d: Could not unlock pi-lock for %p (%d)",
112 w->tid, w->futex, ret);
113 ops++;
114 } while (!done);
115
116 w->ops = ops;
117 return NULL;
118}
119
120static void create_threads(struct worker *w, pthread_attr_t thread_attr,
121 struct perf_cpu_map *cpu)
122{
123 cpu_set_t cpuset;
124 unsigned int i;
125
126 threads_starting = params.nthreads;
127
128 for (i = 0; i < params.nthreads; i++) {
129 worker[i].tid = i;
130
131 if (params.multi) {
132 worker[i].futex = calloc(1, sizeof(u_int32_t));
133 if (!worker[i].futex)
134 err(EXIT_FAILURE, "calloc");
135 } else
136 worker[i].futex = &global_futex;
137
138 CPU_ZERO(&cpuset);
139 CPU_SET(cpu->map[i % cpu->nr], &cpuset);
140
141 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
142 err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
143
144 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i]))
145 err(EXIT_FAILURE, "pthread_create");
146 }
147}
148
149int bench_futex_lock_pi(int argc, const char **argv)
150{
151 int ret = 0;
152 unsigned int i;
153 struct sigaction act;
154 pthread_attr_t thread_attr;
155 struct perf_cpu_map *cpu;
156
157 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0);
158 if (argc)
159 goto err;
160
161 cpu = perf_cpu_map__new(NULL);
162 if (!cpu)
163 err(EXIT_FAILURE, "calloc");
164
165 memset(&act, 0, sizeof(act));
166 sigfillset(&act.sa_mask);
167 act.sa_sigaction = toggle_done;
168 sigaction(SIGINT, &act, NULL);
169
170 if (params.mlockall) {
171 if (mlockall(MCL_CURRENT | MCL_FUTURE))
172 err(EXIT_FAILURE, "mlockall");
173 }
174
175 if (!params.nthreads)
176 params.nthreads = cpu->nr;
177
178 worker = calloc(params.nthreads, sizeof(*worker));
179 if (!worker)
180 err(EXIT_FAILURE, "calloc");
181
182 if (!params.fshared)
183 futex_flag = FUTEX_PRIVATE_FLAG;
184
185 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n",
186 getpid(), params.nthreads, params.runtime);
187
188 init_stats(&throughput_stats);
189 pthread_mutex_init(&thread_lock, NULL);
190 pthread_cond_init(&thread_parent, NULL);
191 pthread_cond_init(&thread_worker, NULL);
192
193 threads_starting = params.nthreads;
194 pthread_attr_init(&thread_attr);
195 gettimeofday(&bench__start, NULL);
196
197 create_threads(worker, thread_attr, cpu);
198 pthread_attr_destroy(&thread_attr);
199
200 pthread_mutex_lock(&thread_lock);
201 while (threads_starting)
202 pthread_cond_wait(&thread_parent, &thread_lock);
203 pthread_cond_broadcast(&thread_worker);
204 pthread_mutex_unlock(&thread_lock);
205
206 sleep(params.runtime);
207 toggle_done(0, NULL, NULL);
208
209 for (i = 0; i < params.nthreads; i++) {
210 ret = pthread_join(worker[i].thread, NULL);
211 if (ret)
212 err(EXIT_FAILURE, "pthread_join");
213 }
214
215
216 pthread_cond_destroy(&thread_parent);
217 pthread_cond_destroy(&thread_worker);
218 pthread_mutex_destroy(&thread_lock);
219
220 for (i = 0; i < params.nthreads; i++) {
221 unsigned long t = bench__runtime.tv_sec > 0 ?
222 worker[i].ops / bench__runtime.tv_sec : 0;
223
224 update_stats(&throughput_stats, t);
225 if (!params.silent)
226 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n",
227 worker[i].tid, worker[i].futex, t);
228
229 if (params.multi)
230 zfree(&worker[i].futex);
231 }
232
233 print_summary();
234
235 free(worker);
236 return ret;
237err:
238 usage_with_options(bench_futex_lock_pi_usage, options);
239 exit(EXIT_FAILURE);
240}
241