xref: /linux-6.15/include/linux/topology.h (revision bcefe12e)
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 <asm/topology.h>
35 
36 #ifndef node_has_online_mem
37 #define node_has_online_mem(nid) (1)
38 #endif
39 
40 #ifndef nr_cpus_node
41 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
42 #endif
43 
44 #define for_each_node_with_cpus(node)			\
45 	for_each_online_node(node)			\
46 		if (nr_cpus_node(node))
47 
48 int arch_update_cpu_topology(void);
49 
50 /* Conform to ACPI 2.0 SLIT distance definitions */
51 #define LOCAL_DISTANCE		10
52 #define REMOTE_DISTANCE		20
53 #ifndef node_distance
54 #define node_distance(from,to)	((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
55 #endif
56 #ifndef RECLAIM_DISTANCE
57 /*
58  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
59  * (in whatever arch specific measurement units returned by node_distance())
60  * then switch on zone reclaim on boot.
61  */
62 #define RECLAIM_DISTANCE 20
63 #endif
64 #ifndef PENALTY_FOR_NODE_WITH_CPUS
65 #define PENALTY_FOR_NODE_WITH_CPUS	(1)
66 #endif
67 
68 /*
69  * Below are the 3 major initializers used in building sched_domains:
70  * SD_SIBLING_INIT, for SMT domains
71  * SD_CPU_INIT, for SMP domains
72  * SD_NODE_INIT, for NUMA 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 				| 0*SD_POWERSAVINGS_BALANCE		\
102 				| 0*SD_SHARE_PKG_RESOURCES		\
103 				| 0*SD_SERIALIZE			\
104 				| 0*SD_PREFER_SIBLING			\
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 				| sd_balance_for_mc_power()		\
137 				| sd_power_saving_flags()		\
138 				,					\
139 	.last_balance		= jiffies,				\
140 	.balance_interval	= 1,					\
141 }
142 #endif
143 #endif /* CONFIG_SCHED_MC */
144 
145 /* Common values for CPUs */
146 #ifndef SD_CPU_INIT
147 #define SD_CPU_INIT (struct sched_domain) {				\
148 	.min_interval		= 1,					\
149 	.max_interval		= 4,					\
150 	.busy_factor		= 64,					\
151 	.imbalance_pct		= 125,					\
152 	.cache_nice_tries	= 1,					\
153 	.busy_idx		= 2,					\
154 	.idle_idx		= 1,					\
155 	.newidle_idx		= 0,					\
156 	.wake_idx		= 0,					\
157 	.forkexec_idx		= 0,					\
158 									\
159 	.flags			= 1*SD_LOAD_BALANCE			\
160 				| 1*SD_BALANCE_NEWIDLE			\
161 				| 1*SD_BALANCE_EXEC			\
162 				| 1*SD_BALANCE_FORK			\
163 				| 0*SD_BALANCE_WAKE			\
164 				| 1*SD_WAKE_AFFINE			\
165 				| 0*SD_PREFER_LOCAL			\
166 				| 0*SD_SHARE_CPUPOWER			\
167 				| 0*SD_SHARE_PKG_RESOURCES		\
168 				| 0*SD_SERIALIZE			\
169 				| sd_balance_for_package_power()	\
170 				| sd_power_saving_flags()		\
171 				,					\
172 	.last_balance		= jiffies,				\
173 	.balance_interval	= 1,					\
174 }
175 #endif
176 
177 /* sched_domains SD_ALLNODES_INIT for NUMA machines */
178 #define SD_ALLNODES_INIT (struct sched_domain) {			\
179 	.min_interval		= 64,					\
180 	.max_interval		= 64*num_online_cpus(),			\
181 	.busy_factor		= 128,					\
182 	.imbalance_pct		= 133,					\
183 	.cache_nice_tries	= 1,					\
184 	.busy_idx		= 3,					\
185 	.idle_idx		= 3,					\
186 	.flags			= 1*SD_LOAD_BALANCE			\
187 				| 1*SD_BALANCE_NEWIDLE			\
188 				| 0*SD_BALANCE_EXEC			\
189 				| 0*SD_BALANCE_FORK			\
190 				| 0*SD_BALANCE_WAKE			\
191 				| 0*SD_WAKE_AFFINE			\
192 				| 0*SD_SHARE_CPUPOWER			\
193 				| 0*SD_POWERSAVINGS_BALANCE		\
194 				| 0*SD_SHARE_PKG_RESOURCES		\
195 				| 1*SD_SERIALIZE			\
196 				| 0*SD_PREFER_SIBLING			\
197 				,					\
198 	.last_balance		= jiffies,				\
199 	.balance_interval	= 64,					\
200 }
201 
202 #ifdef CONFIG_NUMA
203 #ifndef SD_NODE_INIT
204 #error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
205 #endif
206 #endif /* CONFIG_NUMA */
207 
208 #ifndef topology_physical_package_id
209 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
210 #endif
211 #ifndef topology_core_id
212 #define topology_core_id(cpu)			((void)(cpu), 0)
213 #endif
214 #ifndef topology_thread_cpumask
215 #define topology_thread_cpumask(cpu)		cpumask_of(cpu)
216 #endif
217 #ifndef topology_core_cpumask
218 #define topology_core_cpumask(cpu)		cpumask_of(cpu)
219 #endif
220 
221 /* Returns the number of the current Node. */
222 #ifndef numa_node_id
223 #define numa_node_id()		(cpu_to_node(raw_smp_processor_id()))
224 #endif
225 
226 #endif /* _LINUX_TOPOLOGY_H */
227