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
|
/* This example program plays with:
* - finding and counting NUMA nodes
* - manipulating nodesets
* - memory binding and binding policies
*
* Copyright © 2014-2018 Inria. All rights reserved.
* See COPYING in top-level directory.
*/
#include "hwloc.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <assert.h>
int main(void)
{
hwloc_topology_t topology;
hwloc_bitmap_t set;
hwloc_const_bitmap_t cset;
hwloc_membind_policy_t policy;
const struct hwloc_topology_support *support;
int nbnodes;
hwloc_obj_t obj;
char *buffer, *s;
unsigned i;
int err;
/* create a topology */
err = hwloc_topology_init(&topology);
if (err < 0) {
fprintf(stderr, "failed to initialize the topology\n");
return EXIT_FAILURE;
}
err = hwloc_topology_load(topology);
if (err < 0) {
fprintf(stderr, "failed to load the topology\n");
hwloc_topology_destroy(topology);
return EXIT_FAILURE;
}
/* retrieve the entire set of NUMA nodes and count them */
cset = hwloc_topology_get_topology_nodeset(topology);
nbnodes = hwloc_bitmap_weight(cset);
/* there's always at least one NUMA node */
assert(nbnodes > 0);
printf("there are %d nodes in the machine\n", nbnodes);
/* get the process memory binding as a nodeset */
set = hwloc_bitmap_alloc();
if (!set) {
fprintf(stderr, "failed to allocate a bitmap\n");
hwloc_topology_destroy(topology);
return EXIT_FAILURE;
}
err = hwloc_get_membind(topology, set, &policy, HWLOC_MEMBIND_BYNODESET);
if (err < 0) {
fprintf(stderr, "failed to retrieve my memory binding and policy\n");
hwloc_topology_destroy(topology);
hwloc_bitmap_free(set);
return EXIT_FAILURE;
}
/* print the corresponding NUMA nodes */
hwloc_bitmap_asprintf(&s, set);
printf("bound to nodeset %s with contains:\n", s);
free(s);
hwloc_bitmap_foreach_begin(i, set) {
obj = hwloc_get_numanode_obj_by_os_index(topology, i);
printf(" node #%u (OS index %u) with %llu bytes of memory\n",
obj->logical_index, i, (unsigned long long) obj->attr->numanode.local_memory);
} hwloc_bitmap_foreach_end();
hwloc_bitmap_free(set);
/* check alloc+bind support */
support = hwloc_topology_get_support(topology);
if (support->membind->bind_membind) {
printf("BIND memory binding policy is supported\n");
} else {
printf("BIND memory binding policy is NOT supported\n");
}
if (support->membind->alloc_membind) {
printf("Allocating bound memory is supported\n");
} else {
printf("Allocating bound memory is NOT supported\n");
}
/* allocate memory of each nodes */
printf("allocating memory on each node\n");
obj = NULL;
buffer = NULL;
while ((obj = hwloc_get_next_obj_by_type(topology, HWLOC_OBJ_NUMANODE, obj)) != NULL) {
buffer = hwloc_alloc_membind(topology, 4096, obj->nodeset, HWLOC_MEMBIND_BIND,
HWLOC_MEMBIND_STRICT|HWLOC_MEMBIND_BYNODESET);
if (!buffer) {
fprintf(stderr, "failed to allocate memory on node %u\n", obj->os_index);
hwloc_topology_destroy(topology);
return EXIT_SUCCESS;
}
/* now the application must manually manage these different buffers on different nodes */
}
/* check where buffer is allocated */
set = hwloc_bitmap_alloc();
if (!set) {
fprintf(stderr, "failed to allocate a bitmap\n");
hwloc_topology_destroy(topology);
return EXIT_FAILURE;
}
err = hwloc_get_area_membind(topology, buffer, 4096, set, &policy, HWLOC_MEMBIND_BYNODESET);
if (err < 0) {
fprintf(stderr, "failed to retrieve the buffer binding and policy\n");
hwloc_topology_destroy(topology);
hwloc_bitmap_free(set);
return EXIT_FAILURE;
}
/* check the binding policy, it should be what we requested above,
* but may be different if the implementation of different policies
* is identical for the current operating system (e.g. if BIND is the DEFAULT).
*/
printf("buffer membind policy is %d while we requested %d\n",
policy, HWLOC_MEMBIND_BIND);
/* print the corresponding NUMA nodes */
hwloc_bitmap_asprintf(&s, set);
printf("buffer bound to nodeset %s with contains:\n", s);
free(s);
hwloc_bitmap_foreach_begin(i, set) {
obj = hwloc_get_numanode_obj_by_os_index(topology, i);
printf(" node #%u (OS index %u) with %llu bytes of memory\n",
obj->logical_index, i, (unsigned long long) obj->attr->numanode.local_memory);
} hwloc_bitmap_foreach_end();
hwloc_bitmap_free(set);
/* try to migrate the buffer to the first node */
obj = hwloc_get_obj_by_type(topology, HWLOC_OBJ_NUMANODE, 0);
err = hwloc_set_area_membind(topology, buffer, 4096, obj->nodeset, HWLOC_MEMBIND_BIND,
HWLOC_MEMBIND_MIGRATE|HWLOC_MEMBIND_BYNODESET);
if (err < 0) {
fprintf(stderr, "failed to migrate buffer\n");
hwloc_topology_destroy(topology);
return EXIT_FAILURE;
}
hwloc_topology_destroy(topology);
return EXIT_SUCCESS;
}
|
