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/mutex.h"
12 #include "../util/stat.h"
13 #include <subcmd/parse-options.h>
14 #include <linux/compiler.h>
15 #include <linux/kernel.h>
16 #include <linux/zalloc.h>
17 #include <errno.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 #include <sys/mman.h>
26
27 struct worker {
28 int tid;
29 u_int32_t *futex;
30 pthread_t thread;
31 unsigned long ops;
32 };
33
34 static u_int32_t global_futex = 0;
35 static struct worker *worker;
36 static bool done = false;
37 static int futex_flag = 0;
38 static struct mutex thread_lock;
39 static unsigned int threads_starting;
40 static struct stats throughput_stats;
41 static struct cond thread_parent, thread_worker;
42
43 static struct bench_futex_parameters params = {
44 .runtime = 10,
45 };
46
47 static const struct option options[] = {
48 OPT_UINTEGER('t', "threads", ¶ms.nthreads, "Specify amount of threads"),
49 OPT_UINTEGER('r', "runtime", ¶ms.runtime, "Specify runtime (in seconds)"),
50 OPT_BOOLEAN( 'M', "multi", ¶ms.multi, "Use multiple futexes"),
51 OPT_BOOLEAN( 's', "silent", ¶ms.silent, "Silent mode: do not display data/details"),
52 OPT_BOOLEAN( 'S', "shared", ¶ms.fshared, "Use shared futexes instead of private ones"),
53 OPT_BOOLEAN( 'm', "mlockall", ¶ms.mlockall, "Lock all current and future memory"),
54 OPT_END()
55 };
56
57 static const char * const bench_futex_lock_pi_usage[] = {
58 "perf bench futex lock-pi <options>",
59 NULL
60 };
61
print_summary(void)62 static void print_summary(void)
63 {
64 unsigned long avg = avg_stats(&throughput_stats);
65 double stddev = stddev_stats(&throughput_stats);
66
67 printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
68 !params.silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
69 (int)bench__runtime.tv_sec);
70 }
71
toggle_done(int sig __maybe_unused,siginfo_t * info __maybe_unused,void * uc __maybe_unused)72 static void toggle_done(int sig __maybe_unused,
73 siginfo_t *info __maybe_unused,
74 void *uc __maybe_unused)
75 {
76 /* inform all threads that we're done for the day */
77 done = true;
78 gettimeofday(&bench__end, NULL);
79 timersub(&bench__end, &bench__start, &bench__runtime);
80 }
81
workerfn(void * arg)82 static void *workerfn(void *arg)
83 {
84 struct worker *w = (struct worker *) arg;
85 unsigned long ops = w->ops;
86
87 mutex_lock(&thread_lock);
88 threads_starting--;
89 if (!threads_starting)
90 cond_signal(&thread_parent);
91 cond_wait(&thread_worker, &thread_lock);
92 mutex_unlock(&thread_lock);
93
94 do {
95 int ret;
96 again:
97 ret = futex_lock_pi(w->futex, NULL, futex_flag);
98
99 if (ret) { /* handle lock acquisition */
100 if (!params.silent)
101 warn("thread %d: Could not lock pi-lock for %p (%d)",
102 w->tid, w->futex, ret);
103 if (done)
104 break;
105
106 goto again;
107 }
108
109 usleep(1);
110 ret = futex_unlock_pi(w->futex, futex_flag);
111 if (ret && !params.silent)
112 warn("thread %d: Could not unlock pi-lock for %p (%d)",
113 w->tid, w->futex, ret);
114 ops++; /* account for thread's share of work */
115 } while (!done);
116
117 w->ops = ops;
118 return NULL;
119 }
120
create_threads(struct worker * w,struct perf_cpu_map * cpu)121 static void create_threads(struct worker *w, struct perf_cpu_map *cpu)
122 {
123 cpu_set_t *cpuset;
124 unsigned int i;
125 int nrcpus = perf_cpu_map__nr(cpu);
126 size_t size;
127
128 threads_starting = params.nthreads;
129
130 cpuset = CPU_ALLOC(nrcpus);
131 BUG_ON(!cpuset);
132 size = CPU_ALLOC_SIZE(nrcpus);
133
134 for (i = 0; i < params.nthreads; i++) {
135 pthread_attr_t thread_attr;
136
137 pthread_attr_init(&thread_attr);
138 worker[i].tid = i;
139
140 if (params.multi) {
141 worker[i].futex = calloc(1, sizeof(u_int32_t));
142 if (!worker[i].futex)
143 err(EXIT_FAILURE, "calloc");
144 } else
145 worker[i].futex = &global_futex;
146
147 CPU_ZERO_S(size, cpuset);
148 CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
149
150 if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
151 CPU_FREE(cpuset);
152 err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
153 }
154
155 if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i])) {
156 CPU_FREE(cpuset);
157 err(EXIT_FAILURE, "pthread_create");
158 }
159 pthread_attr_destroy(&thread_attr);
160 }
161 CPU_FREE(cpuset);
162 }
163
bench_futex_lock_pi(int argc,const char ** argv)164 int bench_futex_lock_pi(int argc, const char **argv)
165 {
166 int ret = 0;
167 unsigned int i;
168 struct sigaction act;
169 struct perf_cpu_map *cpu;
170
171 argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0);
172 if (argc)
173 goto err;
174
175 cpu = perf_cpu_map__new(NULL);
176 if (!cpu)
177 err(EXIT_FAILURE, "calloc");
178
179 memset(&act, 0, sizeof(act));
180 sigfillset(&act.sa_mask);
181 act.sa_sigaction = toggle_done;
182 sigaction(SIGINT, &act, NULL);
183
184 if (params.mlockall) {
185 if (mlockall(MCL_CURRENT | MCL_FUTURE))
186 err(EXIT_FAILURE, "mlockall");
187 }
188
189 if (!params.nthreads)
190 params.nthreads = perf_cpu_map__nr(cpu);
191
192 worker = calloc(params.nthreads, sizeof(*worker));
193 if (!worker)
194 err(EXIT_FAILURE, "calloc");
195
196 if (!params.fshared)
197 futex_flag = FUTEX_PRIVATE_FLAG;
198
199 printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n",
200 getpid(), params.nthreads, params.runtime);
201
202 init_stats(&throughput_stats);
203 mutex_init(&thread_lock);
204 cond_init(&thread_parent);
205 cond_init(&thread_worker);
206
207 threads_starting = params.nthreads;
208 gettimeofday(&bench__start, NULL);
209
210 create_threads(worker, cpu);
211
212 mutex_lock(&thread_lock);
213 while (threads_starting)
214 cond_wait(&thread_parent, &thread_lock);
215 cond_broadcast(&thread_worker);
216 mutex_unlock(&thread_lock);
217
218 sleep(params.runtime);
219 toggle_done(0, NULL, NULL);
220
221 for (i = 0; i < params.nthreads; i++) {
222 ret = pthread_join(worker[i].thread, NULL);
223 if (ret)
224 err(EXIT_FAILURE, "pthread_join");
225 }
226
227 /* cleanup & report results */
228 cond_destroy(&thread_parent);
229 cond_destroy(&thread_worker);
230 mutex_destroy(&thread_lock);
231
232 for (i = 0; i < params.nthreads; i++) {
233 unsigned long t = bench__runtime.tv_sec > 0 ?
234 worker[i].ops / bench__runtime.tv_sec : 0;
235
236 update_stats(&throughput_stats, t);
237 if (!params.silent)
238 printf("[thread %3d] futex: %p [ %ld ops/sec ]\n",
239 worker[i].tid, worker[i].futex, t);
240
241 if (params.multi)
242 zfree(&worker[i].futex);
243 }
244
245 print_summary();
246
247 free(worker);
248 perf_cpu_map__put(cpu);
249 return ret;
250 err:
251 usage_with_options(bench_futex_lock_pi_usage, options);
252 exit(EXIT_FAILURE);
253 }
254