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
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
|
==============================================================================
NUMA binding description.
==============================================================================
==============================================================================
1 - Introduction
==============================================================================
Systems employing a Non Uniform Memory Access (NUMA) architecture contain
collections of hardware resources including processors, memory, and I/O buses,
that comprise what is commonly known as a NUMA node.
Processor accesses to memory within the local NUMA node is generally faster
than processor accesses to memory outside of the local NUMA node.
DT defines interfaces that allow the platform to convey NUMA node
topology information to OS.
==============================================================================
2 - numa-node-id
==============================================================================
For the purpose of identification, each NUMA node is associated with a unique
token known as a node id. For the purpose of this binding
a node id is a 32-bit integer.
A device node is associated with a NUMA node by the presence of a
numa-node-id property which contains the node id of the device.
Example:
/* numa node 0 */
numa-node-id = <0>;
/* numa node 1 */
numa-node-id = <1>;
==============================================================================
3 - distance-map
==============================================================================
The optional device tree node distance-map describes the relative
distance (memory latency) between all numa nodes.
- compatible : Should at least contain "numa-distance-map-v1".
- distance-matrix
This property defines a matrix to describe the relative distances
between all numa nodes.
It is represented as a list of node pairs and their relative distance.
Note:
1. Each entry represents distance from first node to second node.
The distances are equal in either direction.
2. The distance from a node to self (local distance) is represented
with value 10 and all internode distance should be represented with
a value greater than 10.
3. distance-matrix should have entries in lexicographical ascending
order of nodes.
4. There must be only one device node distance-map which must
reside in the root node.
5. If the distance-map node is not present, a default
distance-matrix is used.
Example:
4 nodes connected in mesh/ring topology as below,
0_______20______1
| |
| |
20 20
| |
| |
|_______________|
3 20 2
if relative distance for each hop is 20,
then internode distance would be,
0 -> 1 = 20
1 -> 2 = 20
2 -> 3 = 20
3 -> 0 = 20
0 -> 2 = 40
1 -> 3 = 40
and dt presentation for this distance matrix is,
distance-map {
compatible = "numa-distance-map-v1";
distance-matrix = <0 0 10>,
<0 1 20>,
<0 2 40>,
<0 3 20>,
<1 0 20>,
<1 1 10>,
<1 2 20>,
<1 3 40>,
<2 0 40>,
<2 1 20>,
<2 2 10>,
<2 3 20>,
<3 0 20>,
<3 1 40>,
<3 2 20>,
<3 3 10>;
};
==============================================================================
4 - Empty memory nodes
==============================================================================
Empty memory nodes, which no memory resides in, are allowed. There are no
device nodes for these empty memory nodes. However, the NUMA node IDs and
distance maps are still valid and memory may be added into them through
hotplug afterwards.
Example:
memory@0 {
device_type = "memory";
reg = <0x0 0x0 0x0 0x80000000>;
numa-node-id = <0>;
};
memory@80000000 {
device_type = "memory";
reg = <0x0 0x80000000 0x0 0x80000000>;
numa-node-id = <1>;
};
/* Empty memory node 2 and 3 */
distance-map {
compatible = "numa-distance-map-v1";
distance-matrix = <0 0 10>,
<0 1 20>,
<0 2 40>,
<0 3 20>,
<1 0 20>,
<1 1 10>,
<1 2 20>,
<1 3 40>,
<2 0 40>,
<2 1 20>,
<2 2 10>,
<2 3 20>,
<3 0 20>,
<3 1 40>,
<3 2 20>,
<3 3 10>;
};
==============================================================================
5 - Example dts
==============================================================================
Dual socket system consists of 2 boards connected through ccn bus and
each board having one socket/soc of 8 cpus, memory and pci bus.
memory@c00000 {
device_type = "memory";
reg = <0x0 0xc00000 0x0 0x80000000>;
/* node 0 */
numa-node-id = <0>;
};
memory@10000000000 {
device_type = "memory";
reg = <0x100 0x0 0x0 0x80000000>;
/* node 1 */
numa-node-id = <1>;
};
cpus {
#address-cells = <2>;
#size-cells = <0>;
cpu@0 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x0>;
enable-method = "psci";
/* node 0 */
numa-node-id = <0>;
};
cpu@1 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x1>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@2 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x2>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@3 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x3>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@4 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x4>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@5 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x5>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@6 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x6>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@7 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x7>;
enable-method = "psci";
numa-node-id = <0>;
};
cpu@8 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x8>;
enable-method = "psci";
/* node 1 */
numa-node-id = <1>;
};
cpu@9 {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0x9>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@a {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xa>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@b {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xb>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@c {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xc>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@d {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xd>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@e {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xe>;
enable-method = "psci";
numa-node-id = <1>;
};
cpu@f {
device_type = "cpu";
compatible = "arm,armv8";
reg = <0x0 0xf>;
enable-method = "psci";
numa-node-id = <1>;
};
};
pcie0: pcie0@848000000000 {
compatible = "arm,armv8";
device_type = "pci";
bus-range = <0 255>;
#size-cells = <2>;
#address-cells = <3>;
reg = <0x8480 0x00000000 0 0x10000000>; /* Configuration space */
ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000 0x70 0x00000000>;
/* node 0 */
numa-node-id = <0>;
};
pcie1: pcie1@948000000000 {
compatible = "arm,armv8";
device_type = "pci";
bus-range = <0 255>;
#size-cells = <2>;
#address-cells = <3>;
reg = <0x9480 0x00000000 0 0x10000000>; /* Configuration space */
ranges = <0x03000000 0x9010 0x00000000 0x9010 0x00000000 0x70 0x00000000>;
/* node 1 */
numa-node-id = <1>;
};
distance-map {
compatible = "numa-distance-map-v1";
distance-matrix = <0 0 10>,
<0 1 20>,
<1 1 10>;
};
|
