1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/*
* Copyright (C) 2013 Davidlohr Bueso <davidlohr@hp.com>
*
* futex-hash: Stress the hell out of the Linux kernel futex uaddr hashing.
*
* This program is particularly useful for measuring the kernel's futex hash
* table/function implementation. In order for it to make sense, use with as
* many threads and futexes as possible.
*/
/* For the CLR_() macros */
#include <pthread.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <sys/time.h>
#include "../util/stat.h"
#include <subcmd/parse-options.h>
#include "bench.h"
#include "futex.h"
#include <err.h>
#include <sys/time.h>
static unsigned int nthreads = 0;
static unsigned int nsecs = 10;
/* amount of futexes per thread */
static unsigned int nfutexes = 1024;
static bool fshared = false, done = false, silent = false;
static int futex_flag = 0;
struct timeval start, end, runtime;
static pthread_mutex_t thread_lock;
static unsigned int threads_starting;
static struct stats throughput_stats;
static pthread_cond_t thread_parent, thread_worker;
struct worker {
int tid;
u_int32_t *futex;
pthread_t thread;
unsigned long ops;
};
static const struct option options[] = {
OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"),
OPT_UINTEGER('f', "futexes", &nfutexes, "Specify amount of futexes per threads"),
OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"),
OPT_END()
};
static const char * const bench_futex_hash_usage[] = {
"perf bench futex hash <options>",
NULL
};
static void *workerfn(void *arg)
{
int ret;
struct worker *w = (struct worker *) arg;
unsigned int i;
unsigned long ops = w->ops; /* avoid cacheline bouncing */
pthread_mutex_lock(&thread_lock);
threads_starting--;
if (!threads_starting)
pthread_cond_signal(&thread_parent);
pthread_cond_wait(&thread_worker, &thread_lock);
pthread_mutex_unlock(&thread_lock);
do {
for (i = 0; i < nfutexes; i++, ops++) {
/*
* We want the futex calls to fail in order to stress
* the hashing of uaddr and not measure other steps,
* such as internal waitqueue handling, thus enlarging
* the critical region protected by hb->lock.
*/
ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
if (!silent &&
(!ret || errno != EAGAIN || errno != EWOULDBLOCK))
warn("Non-expected futex return call");
}
} while (!done);
w->ops = ops;
return NULL;
}
static void toggle_done(int sig __maybe_unused,
siginfo_t *info __maybe_unused,
void *uc __maybe_unused)
{
/* inform all threads that we're done for the day */
done = true;
gettimeofday(&end, NULL);
timersub(&end, &start, &runtime);
}
static void print_summary(void)
{
unsigned long avg = avg_stats(&throughput_stats);
double stddev = stddev_stats(&throughput_stats);
printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
!silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
(int) runtime.tv_sec);
}
int bench_futex_hash(int argc, const char **argv,
const char *prefix __maybe_unused)
{
int ret = 0;
cpu_set_t cpu;
struct sigaction act;
unsigned int i, ncpus;
pthread_attr_t thread_attr;
struct worker *worker = NULL;
argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
if (argc) {
usage_with_options(bench_futex_hash_usage, options);
exit(EXIT_FAILURE);
}
ncpus = sysconf(_SC_NPROCESSORS_ONLN);
nsecs = futexbench_sanitize_numeric(nsecs);
nfutexes = futexbench_sanitize_numeric(nfutexes);
sigfillset(&act.sa_mask);
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);
if (!nthreads) /* default to the number of CPUs */
nthreads = ncpus;
else
nthreads = futexbench_sanitize_numeric(nthreads);
worker = calloc(nthreads, sizeof(*worker));
if (!worker)
goto errmem;
if (!fshared)
futex_flag = FUTEX_PRIVATE_FLAG;
printf("Run summary [PID %d]: %d threads, each operating on %d [%s] futexes for %d secs.\n\n",
getpid(), nthreads, nfutexes, fshared ? "shared":"private", nsecs);
init_stats(&throughput_stats);
pthread_mutex_init(&thread_lock, NULL);
pthread_cond_init(&thread_parent, NULL);
pthread_cond_init(&thread_worker, NULL);
threads_starting = nthreads;
pthread_attr_init(&thread_attr);
gettimeofday(&start, NULL);
for (i = 0; i < nthreads; i++) {
worker[i].tid = i;
worker[i].futex = calloc(nfutexes, sizeof(*worker[i].futex));
if (!worker[i].futex)
goto errmem;
CPU_ZERO(&cpu);
CPU_SET(i % ncpus, &cpu);
ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu);
if (ret)
err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
ret = pthread_create(&worker[i].thread, &thread_attr, workerfn,
(void *)(struct worker *) &worker[i]);
if (ret)
err(EXIT_FAILURE, "pthread_create");
}
pthread_attr_destroy(&thread_attr);
pthread_mutex_lock(&thread_lock);
while (threads_starting)
pthread_cond_wait(&thread_parent, &thread_lock);
pthread_cond_broadcast(&thread_worker);
pthread_mutex_unlock(&thread_lock);
sleep(nsecs);
toggle_done(0, NULL, NULL);
for (i = 0; i < nthreads; i++) {
ret = pthread_join(worker[i].thread, NULL);
if (ret)
err(EXIT_FAILURE, "pthread_join");
}
/* cleanup & report results */
pthread_cond_destroy(&thread_parent);
pthread_cond_destroy(&thread_worker);
pthread_mutex_destroy(&thread_lock);
for (i = 0; i < nthreads; i++) {
unsigned long t = worker[i].ops/runtime.tv_sec;
update_stats(&throughput_stats, t);
if (!silent) {
if (nfutexes == 1)
printf("[thread %2d] futex: %p [ %ld ops/sec ]\n",
worker[i].tid, &worker[i].futex[0], t);
else
printf("[thread %2d] futexes: %p ... %p [ %ld ops/sec ]\n",
worker[i].tid, &worker[i].futex[0],
&worker[i].futex[nfutexes-1], t);
}
free(worker[i].futex);
}
print_summary();
free(worker);
return ret;
errmem:
err(EXIT_FAILURE, "calloc");
}
|
