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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* POWER Data Stream Control Register (DSCR) default test
*
* This test modifies the system wide default DSCR through
* it's sysfs interface and then verifies that all threads
* see the correct changed DSCR value immediately.
*
* Copyright 2012, Anton Blanchard, IBM Corporation.
* Copyright 2015, Anshuman Khandual, IBM Corporation.
*/
#define _GNU_SOURCE
#include "dscr.h"
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>
static void *dscr_default_lockstep_writer(void *arg)
{
sem_t *reader_sem = (sem_t *)arg;
sem_t *writer_sem = (sem_t *)arg + 1;
unsigned long expected_dscr = 0;
for (int i = 0; i < COUNT; i++) {
FAIL_IF_EXIT(sem_wait(writer_sem));
set_default_dscr(expected_dscr);
expected_dscr = (expected_dscr + 1) % DSCR_MAX;
FAIL_IF_EXIT(sem_post(reader_sem));
}
return NULL;
}
int dscr_default_lockstep_test(void)
{
pthread_t writer;
sem_t rw_semaphores[2];
sem_t *reader_sem = &rw_semaphores[0];
sem_t *writer_sem = &rw_semaphores[1];
unsigned long expected_dscr = 0;
SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
FAIL_IF(sem_init(reader_sem, 0, 0));
FAIL_IF(sem_init(writer_sem, 0, 1)); /* writer starts first */
FAIL_IF(bind_to_cpu(BIND_CPU_ANY) < 0);
FAIL_IF(pthread_create(&writer, NULL, dscr_default_lockstep_writer, (void *)rw_semaphores));
for (int i = 0; i < COUNT ; i++) {
FAIL_IF(sem_wait(reader_sem));
FAIL_IF(get_dscr() != expected_dscr);
FAIL_IF(get_dscr_usr() != expected_dscr);
expected_dscr = (expected_dscr + 1) % DSCR_MAX;
FAIL_IF(sem_post(writer_sem));
}
FAIL_IF(pthread_join(writer, NULL));
FAIL_IF(sem_destroy(reader_sem));
FAIL_IF(sem_destroy(writer_sem));
return 0;
}
struct random_thread_args {
pthread_t thread_id;
unsigned long *expected_system_dscr;
pthread_rwlock_t *rw_lock;
pthread_barrier_t *barrier;
};
static void *dscr_default_random_thread(void *in)
{
struct random_thread_args *args = (struct random_thread_args *)in;
unsigned long *expected_dscr_p = args->expected_system_dscr;
pthread_rwlock_t *rw_lock = args->rw_lock;
int err;
srand(gettid());
err = pthread_barrier_wait(args->barrier);
FAIL_IF_EXIT(err != 0 && err != PTHREAD_BARRIER_SERIAL_THREAD);
for (int i = 0; i < COUNT; i++) {
unsigned long expected_dscr;
unsigned long current_dscr;
unsigned long current_dscr_usr;
FAIL_IF_EXIT(pthread_rwlock_rdlock(rw_lock));
expected_dscr = *expected_dscr_p;
current_dscr = get_dscr();
current_dscr_usr = get_dscr_usr();
FAIL_IF_EXIT(pthread_rwlock_unlock(rw_lock));
FAIL_IF_EXIT(current_dscr != expected_dscr);
FAIL_IF_EXIT(current_dscr_usr != expected_dscr);
if (rand() % 10 == 0) {
unsigned long next_dscr;
FAIL_IF_EXIT(pthread_rwlock_wrlock(rw_lock));
next_dscr = (*expected_dscr_p + 1) % DSCR_MAX;
set_default_dscr(next_dscr);
*expected_dscr_p = next_dscr;
FAIL_IF_EXIT(pthread_rwlock_unlock(rw_lock));
}
}
pthread_exit((void *)0);
}
int dscr_default_random_test(void)
{
struct random_thread_args threads[THREADS];
unsigned long expected_system_dscr = 0;
pthread_rwlockattr_t rwlock_attr;
pthread_rwlock_t rw_lock;
pthread_barrier_t barrier;
SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
FAIL_IF(pthread_rwlockattr_setkind_np(&rwlock_attr,
PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP));
FAIL_IF(pthread_rwlock_init(&rw_lock, &rwlock_attr));
FAIL_IF(pthread_barrier_init(&barrier, NULL, THREADS));
set_default_dscr(expected_system_dscr);
for (int i = 0; i < THREADS; i++) {
threads[i].expected_system_dscr = &expected_system_dscr;
threads[i].rw_lock = &rw_lock;
threads[i].barrier = &barrier;
FAIL_IF(pthread_create(&threads[i].thread_id, NULL,
dscr_default_random_thread, (void *)&threads[i]));
}
for (int i = 0; i < THREADS; i++)
FAIL_IF(pthread_join(threads[i].thread_id, NULL));
FAIL_IF(pthread_barrier_destroy(&barrier));
FAIL_IF(pthread_rwlock_destroy(&rw_lock));
return 0;
}
int main(int argc, char *argv[])
{
unsigned long orig_dscr_default = 0;
int err = 0;
if (have_hwcap2(PPC_FEATURE2_DSCR))
orig_dscr_default = get_default_dscr();
err |= test_harness(dscr_default_lockstep_test, "dscr_default_lockstep_test");
err |= test_harness(dscr_default_random_test, "dscr_default_random_test");
if (have_hwcap2(PPC_FEATURE2_DSCR))
set_default_dscr(orig_dscr_default);
return err;
}
|
