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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
/* Generic test for CPU affinity functions, multi-threaded variant.
Copyright (C) 2015-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Before including this file, a test has to declare the helper
getaffinity and setaffinity functions described in
tst-skeleton-affinity.c, which is included below. */
#include <errno.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdlib.h>
#include <support/xthread.h>
#include <sys/time.h>
struct conf;
static bool early_test (struct conf *);
/* Arbitrary run time for each pass. */
#define PASS_TIMEOUT 2
/* There are two passes (one with sched_yield, one without), and we
double the timeout to be on the safe side. */
#define TIMEOUT (2 * PASS_TIMEOUT * 2)
#include "tst-skeleton-affinity.c"
/* 0 if still running, 1 of stopping requested. */
static int still_running;
/* 0 if no scheduling failures, 1 if failures are encountered. */
static int failed;
static void *
thread_burn_one_cpu (void *closure)
{
int cpu = (uintptr_t) closure;
while (__atomic_load_n (&still_running, __ATOMIC_RELAXED) == 0)
{
int current = sched_getcpu ();
if (sched_getcpu () != cpu)
{
printf ("error: Pinned thread %d ran on impossible cpu %d\n",
cpu, current);
__atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
/* Terminate early. */
__atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
}
}
return NULL;
}
struct burn_thread
{
pthread_t self;
struct conf *conf;
cpu_set_t *initial_set;
cpu_set_t *seen_set;
int thread;
};
static void *
thread_burn_any_cpu (void *closure)
{
struct burn_thread *param = closure;
/* Schedule this thread around a bit to see if it lands on another
CPU. Run this for 2 seconds, once with sched_yield, once
without. */
for (int pass = 1; pass <= 2; ++pass)
{
time_t start = time (NULL);
while (time (NULL) - start <= PASS_TIMEOUT)
{
int cpu = sched_getcpu ();
if (cpu > param->conf->last_cpu
|| !CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
param->initial_set))
{
printf ("error: Unpinned thread %d ran on impossible CPU %d\n",
param->thread, cpu);
__atomic_store_n (&failed, 1, __ATOMIC_RELAXED);
return NULL;
}
CPU_SET_S (cpu, CPU_ALLOC_SIZE (param->conf->set_size),
param->seen_set);
if (pass == 1)
sched_yield ();
}
}
return NULL;
}
static void
stop_and_join_threads (struct conf *conf, cpu_set_t *set,
pthread_t *pinned_first, pthread_t *pinned_last,
struct burn_thread *other_first,
struct burn_thread *other_last)
{
__atomic_store_n (&still_running, 1, __ATOMIC_RELAXED);
for (pthread_t *p = pinned_first; p < pinned_last; ++p)
{
int cpu = p - pinned_first;
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
continue;
int ret = pthread_join (*p, NULL);
if (ret != 0)
{
printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
fflush (stdout);
/* Cannot shut down cleanly with threads still running. */
abort ();
}
}
for (struct burn_thread *p = other_first; p < other_last; ++p)
{
int cpu = p - other_first;
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), set))
continue;
int ret = pthread_join (p->self, NULL);
if (ret != 0)
{
printf ("error: Failed to join thread %d: %s\n", cpu, strerror (ret));
fflush (stdout);
/* Cannot shut down cleanly with threads still running. */
abort ();
}
}
}
/* Tries to check that the initial set of CPUs is complete and that
the main thread will not run on any other threads. */
static bool
early_test (struct conf *conf)
{
pthread_t *pinned_threads
= calloc (conf->last_cpu + 1, sizeof (*pinned_threads));
struct burn_thread *other_threads
= calloc (conf->last_cpu + 1, sizeof (*other_threads));
cpu_set_t *initial_set = CPU_ALLOC (conf->set_size);
cpu_set_t *scratch_set = CPU_ALLOC (conf->set_size);
if (pinned_threads == NULL || other_threads == NULL
|| initial_set == NULL || scratch_set == NULL)
{
puts ("error: Memory allocation failure");
return false;
}
if (getaffinity (CPU_ALLOC_SIZE (conf->set_size), initial_set) < 0)
{
printf ("error: pthread_getaffinity_np failed: %m\n");
return false;
}
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
other_threads[cpu].conf = conf;
other_threads[cpu].initial_set = initial_set;
other_threads[cpu].thread = cpu;
other_threads[cpu].seen_set = CPU_ALLOC (conf->set_size);
if (other_threads[cpu].seen_set == NULL)
{
puts ("error: Memory allocation failure");
return false;
}
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size),
other_threads[cpu].seen_set);
}
pthread_attr_t attr;
int ret = pthread_attr_init (&attr);
if (ret != 0)
{
printf ("error: pthread_attr_init failed: %s\n", strerror (ret));
return false;
}
support_set_small_thread_stack_size (&attr);
/* Spawn a thread pinned to each available CPU. */
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
CPU_SET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
ret = pthread_attr_setaffinity_np
(&attr, CPU_ALLOC_SIZE (conf->set_size), scratch_set);
if (ret != 0)
{
printf ("error: pthread_attr_setaffinity_np for CPU %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads, pinned_threads + cpu,
NULL, NULL);
return false;
}
ret = pthread_create (pinned_threads + cpu, &attr,
thread_burn_one_cpu, (void *) (uintptr_t) cpu);
if (ret != 0)
{
printf ("error: pthread_create for CPU %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads, pinned_threads + cpu,
NULL, NULL);
return false;
}
}
/* Spawn another set of threads running on all CPUs. */
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
ret = pthread_create (&other_threads[cpu].self,
support_small_stack_thread_attribute (),
thread_burn_any_cpu, other_threads + cpu);
if (ret != 0)
{
printf ("error: pthread_create for thread %d failed: %s\n",
cpu, strerror (ret));
stop_and_join_threads (conf, initial_set,
pinned_threads,
pinned_threads + conf->last_cpu + 1,
other_threads, other_threads + cpu);
return false;
}
}
/* Main thread. */
struct burn_thread main_thread;
main_thread.conf = conf;
main_thread.initial_set = initial_set;
main_thread.seen_set = scratch_set;
main_thread.thread = -1;
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), main_thread.seen_set);
thread_burn_any_cpu (&main_thread);
stop_and_join_threads (conf, initial_set,
pinned_threads,
pinned_threads + conf->last_cpu + 1,
other_threads, other_threads + conf->last_cpu + 1);
printf ("info: Main thread ran on %d CPU(s) of %d available CPU(s)\n",
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set),
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), initial_set));
CPU_ZERO_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set);
for (int cpu = 0; cpu <= conf->last_cpu; ++cpu)
{
if (!CPU_ISSET_S (cpu, CPU_ALLOC_SIZE (conf->set_size), initial_set))
continue;
CPU_OR_S (CPU_ALLOC_SIZE (conf->set_size),
scratch_set, scratch_set, other_threads[cpu].seen_set);
CPU_FREE (other_threads[cpu].seen_set);
}
printf ("info: Other threads ran on %d CPU(s)\n",
CPU_COUNT_S (CPU_ALLOC_SIZE (conf->set_size), scratch_set));;
pthread_attr_destroy (&attr);
CPU_FREE (scratch_set);
CPU_FREE (initial_set);
free (pinned_threads);
free (other_threads);
return failed == 0;
}
|
