xref: /linux-6.15/include/linux/topology.h (revision b9ccfda2)
1 /*
2  * include/linux/topology.h
3  *
4  * Written by: Matthew Dobson, IBM Corporation
5  *
6  * Copyright (C) 2002, IBM Corp.
7  *
8  * All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18  * NON INFRINGEMENT.  See the GNU General Public License for more
19  * details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24  *
25  * Send feedback to <[email protected]>
26  */
27 #ifndef _LINUX_TOPOLOGY_H
28 #define _LINUX_TOPOLOGY_H
29 
30 #include <linux/cpumask.h>
31 #include <linux/bitops.h>
32 #include <linux/mmzone.h>
33 #include <linux/smp.h>
34 #include <linux/percpu.h>
35 #include <asm/topology.h>
36 
37 #ifndef node_has_online_mem
38 #define node_has_online_mem(nid) (1)
39 #endif
40 
41 #ifndef nr_cpus_node
42 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
43 #endif
44 
45 #define for_each_node_with_cpus(node)			\
46 	for_each_online_node(node)			\
47 		if (nr_cpus_node(node))
48 
49 int arch_update_cpu_topology(void);
50 
51 /* Conform to ACPI 2.0 SLIT distance definitions */
52 #define LOCAL_DISTANCE		10
53 #define REMOTE_DISTANCE		20
54 #ifndef node_distance
55 #define node_distance(from,to)	((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
56 #endif
57 #ifndef RECLAIM_DISTANCE
58 /*
59  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
60  * (in whatever arch specific measurement units returned by node_distance())
61  * then switch on zone reclaim on boot.
62  */
63 #define RECLAIM_DISTANCE 30
64 #endif
65 #ifndef PENALTY_FOR_NODE_WITH_CPUS
66 #define PENALTY_FOR_NODE_WITH_CPUS	(1)
67 #endif
68 
69 /*
70  * Below are the 3 major initializers used in building sched_domains:
71  * SD_SIBLING_INIT, for SMT domains
72  * SD_CPU_INIT, for SMP domains
73  *
74  * Any architecture that cares to do any tuning to these values should do so
75  * by defining their own arch-specific initializer in include/asm/topology.h.
76  * A definition there will automagically override these default initializers
77  * and allow arch-specific performance tuning of sched_domains.
78  * (Only non-zero and non-null fields need be specified.)
79  */
80 
81 #ifdef CONFIG_SCHED_SMT
82 /* MCD - Do we really need this?  It is always on if CONFIG_SCHED_SMT is,
83  * so can't we drop this in favor of CONFIG_SCHED_SMT?
84  */
85 #define ARCH_HAS_SCHED_WAKE_IDLE
86 /* Common values for SMT siblings */
87 #ifndef SD_SIBLING_INIT
88 #define SD_SIBLING_INIT (struct sched_domain) {				\
89 	.min_interval		= 1,					\
90 	.max_interval		= 2,					\
91 	.busy_factor		= 64,					\
92 	.imbalance_pct		= 110,					\
93 									\
94 	.flags			= 1*SD_LOAD_BALANCE			\
95 				| 1*SD_BALANCE_NEWIDLE			\
96 				| 1*SD_BALANCE_EXEC			\
97 				| 1*SD_BALANCE_FORK			\
98 				| 0*SD_BALANCE_WAKE			\
99 				| 1*SD_WAKE_AFFINE			\
100 				| 1*SD_SHARE_CPUPOWER			\
101 				| 1*SD_SHARE_PKG_RESOURCES		\
102 				| 0*SD_SERIALIZE			\
103 				| 0*SD_PREFER_SIBLING			\
104 				| arch_sd_sibling_asym_packing()	\
105 				,					\
106 	.last_balance		= jiffies,				\
107 	.balance_interval	= 1,					\
108 	.smt_gain		= 1178,	/* 15% */			\
109 }
110 #endif
111 #endif /* CONFIG_SCHED_SMT */
112 
113 #ifdef CONFIG_SCHED_MC
114 /* Common values for MC siblings. for now mostly derived from SD_CPU_INIT */
115 #ifndef SD_MC_INIT
116 #define SD_MC_INIT (struct sched_domain) {				\
117 	.min_interval		= 1,					\
118 	.max_interval		= 4,					\
119 	.busy_factor		= 64,					\
120 	.imbalance_pct		= 125,					\
121 	.cache_nice_tries	= 1,					\
122 	.busy_idx		= 2,					\
123 	.wake_idx		= 0,					\
124 	.forkexec_idx		= 0,					\
125 									\
126 	.flags			= 1*SD_LOAD_BALANCE			\
127 				| 1*SD_BALANCE_NEWIDLE			\
128 				| 1*SD_BALANCE_EXEC			\
129 				| 1*SD_BALANCE_FORK			\
130 				| 0*SD_BALANCE_WAKE			\
131 				| 1*SD_WAKE_AFFINE			\
132 				| 0*SD_PREFER_LOCAL			\
133 				| 0*SD_SHARE_CPUPOWER			\
134 				| 1*SD_SHARE_PKG_RESOURCES		\
135 				| 0*SD_SERIALIZE			\
136 				,					\
137 	.last_balance		= jiffies,				\
138 	.balance_interval	= 1,					\
139 }
140 #endif
141 #endif /* CONFIG_SCHED_MC */
142 
143 /* Common values for CPUs */
144 #ifndef SD_CPU_INIT
145 #define SD_CPU_INIT (struct sched_domain) {				\
146 	.min_interval		= 1,					\
147 	.max_interval		= 4,					\
148 	.busy_factor		= 64,					\
149 	.imbalance_pct		= 125,					\
150 	.cache_nice_tries	= 1,					\
151 	.busy_idx		= 2,					\
152 	.idle_idx		= 1,					\
153 	.newidle_idx		= 0,					\
154 	.wake_idx		= 0,					\
155 	.forkexec_idx		= 0,					\
156 									\
157 	.flags			= 1*SD_LOAD_BALANCE			\
158 				| 1*SD_BALANCE_NEWIDLE			\
159 				| 1*SD_BALANCE_EXEC			\
160 				| 1*SD_BALANCE_FORK			\
161 				| 0*SD_BALANCE_WAKE			\
162 				| 1*SD_WAKE_AFFINE			\
163 				| 0*SD_PREFER_LOCAL			\
164 				| 0*SD_SHARE_CPUPOWER			\
165 				| 0*SD_SHARE_PKG_RESOURCES		\
166 				| 0*SD_SERIALIZE			\
167 				,					\
168 	.last_balance		= jiffies,				\
169 	.balance_interval	= 1,					\
170 }
171 #endif
172 
173 #ifdef CONFIG_SCHED_BOOK
174 #ifndef SD_BOOK_INIT
175 #error Please define an appropriate SD_BOOK_INIT in include/asm/topology.h!!!
176 #endif
177 #endif /* CONFIG_SCHED_BOOK */
178 
179 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
180 DECLARE_PER_CPU(int, numa_node);
181 
182 #ifndef numa_node_id
183 /* Returns the number of the current Node. */
184 static inline int numa_node_id(void)
185 {
186 	return __this_cpu_read(numa_node);
187 }
188 #endif
189 
190 #ifndef cpu_to_node
191 static inline int cpu_to_node(int cpu)
192 {
193 	return per_cpu(numa_node, cpu);
194 }
195 #endif
196 
197 #ifndef set_numa_node
198 static inline void set_numa_node(int node)
199 {
200 	this_cpu_write(numa_node, node);
201 }
202 #endif
203 
204 #ifndef set_cpu_numa_node
205 static inline void set_cpu_numa_node(int cpu, int node)
206 {
207 	per_cpu(numa_node, cpu) = node;
208 }
209 #endif
210 
211 #else	/* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
212 
213 /* Returns the number of the current Node. */
214 #ifndef numa_node_id
215 static inline int numa_node_id(void)
216 {
217 	return cpu_to_node(raw_smp_processor_id());
218 }
219 #endif
220 
221 #endif	/* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
222 
223 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
224 
225 /*
226  * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
227  * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
228  * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
229  */
230 DECLARE_PER_CPU(int, _numa_mem_);
231 
232 #ifndef set_numa_mem
233 static inline void set_numa_mem(int node)
234 {
235 	this_cpu_write(_numa_mem_, node);
236 }
237 #endif
238 
239 #ifndef numa_mem_id
240 /* Returns the number of the nearest Node with memory */
241 static inline int numa_mem_id(void)
242 {
243 	return __this_cpu_read(_numa_mem_);
244 }
245 #endif
246 
247 #ifndef cpu_to_mem
248 static inline int cpu_to_mem(int cpu)
249 {
250 	return per_cpu(_numa_mem_, cpu);
251 }
252 #endif
253 
254 #ifndef set_cpu_numa_mem
255 static inline void set_cpu_numa_mem(int cpu, int node)
256 {
257 	per_cpu(_numa_mem_, cpu) = node;
258 }
259 #endif
260 
261 #else	/* !CONFIG_HAVE_MEMORYLESS_NODES */
262 
263 #ifndef numa_mem_id
264 /* Returns the number of the nearest Node with memory */
265 static inline int numa_mem_id(void)
266 {
267 	return numa_node_id();
268 }
269 #endif
270 
271 #ifndef cpu_to_mem
272 static inline int cpu_to_mem(int cpu)
273 {
274 	return cpu_to_node(cpu);
275 }
276 #endif
277 
278 #endif	/* [!]CONFIG_HAVE_MEMORYLESS_NODES */
279 
280 #ifndef topology_physical_package_id
281 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
282 #endif
283 #ifndef topology_core_id
284 #define topology_core_id(cpu)			((void)(cpu), 0)
285 #endif
286 #ifndef topology_thread_cpumask
287 #define topology_thread_cpumask(cpu)		cpumask_of(cpu)
288 #endif
289 #ifndef topology_core_cpumask
290 #define topology_core_cpumask(cpu)		cpumask_of(cpu)
291 #endif
292 
293 #endif /* _LINUX_TOPOLOGY_H */
294