This source file includes following definitions.
- print_summary
- workerfn
- block_threads
- toggle_done
- bench_futex_requeue
1
2
3
4
5
6
7
8
9
10
11
12
13 #include <string.h>
14 #include <pthread.h>
15
16 #include <signal.h>
17 #include "../util/stat.h"
18 #include <subcmd/parse-options.h>
19 #include <linux/compiler.h>
20 #include <linux/kernel.h>
21 #include <linux/time64.h>
22 #include <errno.h>
23 #include <internal/cpumap.h>
24 #include <perf/cpumap.h>
25 #include "bench.h"
26 #include "futex.h"
27
28 #include <err.h>
29 #include <stdlib.h>
30 #include <sys/time.h>
31
32 static u_int32_t futex1 = 0, futex2 = 0;
33
34
35
36
37
38 static unsigned int nrequeue = 1;
39
40 static pthread_t *worker;
41 static bool done = false, silent = false, fshared = false;
42 static pthread_mutex_t thread_lock;
43 static pthread_cond_t thread_parent, thread_worker;
44 static struct stats requeuetime_stats, requeued_stats;
45 static unsigned int threads_starting, nthreads = 0;
46 static int futex_flag = 0;
47
48 static const struct option options[] = {
49 OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
50 OPT_UINTEGER('q', "nrequeue", &nrequeue, "Specify amount of threads to requeue at once"),
51 OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
52 OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"),
53 OPT_END()
54 };
55
56 static const char * const bench_futex_requeue_usage[] = {
57 "perf bench futex requeue <options>",
58 NULL
59 };
60
61 static void print_summary(void)
62 {
63 double requeuetime_avg = avg_stats(&requeuetime_stats);
64 double requeuetime_stddev = stddev_stats(&requeuetime_stats);
65 unsigned int requeued_avg = avg_stats(&requeued_stats);
66
67 printf("Requeued %d of %d threads in %.4f ms (+-%.2f%%)\n",
68 requeued_avg,
69 nthreads,
70 requeuetime_avg / USEC_PER_MSEC,
71 rel_stddev_stats(requeuetime_stddev, requeuetime_avg));
72 }
73
74 static void *workerfn(void *arg __maybe_unused)
75 {
76 pthread_mutex_lock(&thread_lock);
77 threads_starting--;
78 if (!threads_starting)
79 pthread_cond_signal(&thread_parent);
80 pthread_cond_wait(&thread_worker, &thread_lock);
81 pthread_mutex_unlock(&thread_lock);
82
83 futex_wait(&futex1, 0, NULL, futex_flag);
84 return NULL;
85 }
86
87 static void block_threads(pthread_t *w,
88 pthread_attr_t thread_attr, struct perf_cpu_map *cpu)
89 {
90 cpu_set_t cpuset;
91 unsigned int i;
92
93 threads_starting = nthreads;
94
95
96 for (i = 0; i < nthreads; i++) {
97 CPU_ZERO(&cpuset);
98 CPU_SET(cpu->map[i % cpu->nr], &cpuset);
99
100 if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
101 err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
102
103 if (pthread_create(&w[i], &thread_attr, workerfn, NULL))
104 err(EXIT_FAILURE, "pthread_create");
105 }
106 }
107
108 static void toggle_done(int sig __maybe_unused,
109 siginfo_t *info __maybe_unused,
110 void *uc __maybe_unused)
111 {
112 done = true;
113 }
114
115 int bench_futex_requeue(int argc, const char **argv)
116 {
117 int ret = 0;
118 unsigned int i, j;
119 struct sigaction act;
120 pthread_attr_t thread_attr;
121 struct perf_cpu_map *cpu;
122
123 argc = parse_options(argc, argv, options, bench_futex_requeue_usage, 0);
124 if (argc)
125 goto err;
126
127 cpu = perf_cpu_map__new(NULL);
128 if (!cpu)
129 err(EXIT_FAILURE, "cpu_map__new");
130
131 sigfillset(&act.sa_mask);
132 act.sa_sigaction = toggle_done;
133 sigaction(SIGINT, &act, NULL);
134
135 if (!nthreads)
136 nthreads = cpu->nr;
137
138 worker = calloc(nthreads, sizeof(*worker));
139 if (!worker)
140 err(EXIT_FAILURE, "calloc");
141
142 if (!fshared)
143 futex_flag = FUTEX_PRIVATE_FLAG;
144
145 if (nrequeue > nthreads)
146 nrequeue = nthreads;
147
148 printf("Run summary [PID %d]: Requeuing %d threads (from [%s] %p to %p), "
149 "%d at a time.\n\n", getpid(), nthreads,
150 fshared ? "shared":"private", &futex1, &futex2, nrequeue);
151
152 init_stats(&requeued_stats);
153 init_stats(&requeuetime_stats);
154 pthread_attr_init(&thread_attr);
155 pthread_mutex_init(&thread_lock, NULL);
156 pthread_cond_init(&thread_parent, NULL);
157 pthread_cond_init(&thread_worker, NULL);
158
159 for (j = 0; j < bench_repeat && !done; j++) {
160 unsigned int nrequeued = 0;
161 struct timeval start, end, runtime;
162
163
164 block_threads(worker, thread_attr, cpu);
165
166
167 pthread_mutex_lock(&thread_lock);
168 while (threads_starting)
169 pthread_cond_wait(&thread_parent, &thread_lock);
170 pthread_cond_broadcast(&thread_worker);
171 pthread_mutex_unlock(&thread_lock);
172
173 usleep(100000);
174
175
176 gettimeofday(&start, NULL);
177 while (nrequeued < nthreads) {
178
179
180
181
182 nrequeued += futex_cmp_requeue(&futex1, 0, &futex2, 0,
183 nrequeue, futex_flag);
184 }
185
186 gettimeofday(&end, NULL);
187 timersub(&end, &start, &runtime);
188
189 update_stats(&requeued_stats, nrequeued);
190 update_stats(&requeuetime_stats, runtime.tv_usec);
191
192 if (!silent) {
193 printf("[Run %d]: Requeued %d of %d threads in %.4f ms\n",
194 j + 1, nrequeued, nthreads, runtime.tv_usec / (double)USEC_PER_MSEC);
195 }
196
197
198 nrequeued = futex_wake(&futex2, nrequeued, futex_flag);
199 if (nthreads != nrequeued)
200 warnx("couldn't wakeup all tasks (%d/%d)", nrequeued, nthreads);
201
202 for (i = 0; i < nthreads; i++) {
203 ret = pthread_join(worker[i], NULL);
204 if (ret)
205 err(EXIT_FAILURE, "pthread_join");
206 }
207 }
208
209
210 pthread_cond_destroy(&thread_parent);
211 pthread_cond_destroy(&thread_worker);
212 pthread_mutex_destroy(&thread_lock);
213 pthread_attr_destroy(&thread_attr);
214
215 print_summary();
216
217 free(worker);
218 return ret;
219 err:
220 usage_with_options(bench_futex_requeue_usage, options);
221 exit(EXIT_FAILURE);
222 }