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/arch_topology.h> 31 #include <linux/cpumask.h> 32 #include <linux/bitops.h> 33 #include <linux/mmzone.h> 34 #include <linux/smp.h> 35 #include <linux/percpu.h> 36 #include <asm/topology.h> 37 38 #ifndef nr_cpus_node 39 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node)) 40 #endif 41 42 #define for_each_node_with_cpus(node) \ 43 for_each_online_node(node) \ 44 if (nr_cpus_node(node)) 45 46 int arch_update_cpu_topology(void); 47 48 /* Conform to ACPI 2.0 SLIT distance definitions */ 49 #define LOCAL_DISTANCE 10 50 #define REMOTE_DISTANCE 20 51 #ifndef node_distance 52 #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE) 53 #endif 54 #ifndef RECLAIM_DISTANCE 55 /* 56 * If the distance between nodes in a system is larger than RECLAIM_DISTANCE 57 * (in whatever arch specific measurement units returned by node_distance()) 58 * and node_reclaim_mode is enabled then the VM will only call node_reclaim() 59 * on nodes within this distance. 60 */ 61 #define RECLAIM_DISTANCE 30 62 #endif 63 64 /* 65 * The following tunable allows platforms to override the default node 66 * reclaim distance (RECLAIM_DISTANCE) if remote memory accesses are 67 * sufficiently fast that the default value actually hurts 68 * performance. 69 * 70 * AMD EPYC machines use this because even though the 2-hop distance 71 * is 32 (3.2x slower than a local memory access) performance actually 72 * *improves* if allowed to reclaim memory and load balance tasks 73 * between NUMA nodes 2-hops apart. 74 */ 75 extern int __read_mostly node_reclaim_distance; 76 77 #ifndef PENALTY_FOR_NODE_WITH_CPUS 78 #define PENALTY_FOR_NODE_WITH_CPUS (1) 79 #endif 80 81 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 82 DECLARE_PER_CPU(int, numa_node); 83 84 #ifndef numa_node_id 85 /* Returns the number of the current Node. */ 86 static inline int numa_node_id(void) 87 { 88 return raw_cpu_read(numa_node); 89 } 90 #endif 91 92 #ifndef cpu_to_node 93 static inline int cpu_to_node(int cpu) 94 { 95 return per_cpu(numa_node, cpu); 96 } 97 #endif 98 99 #ifndef set_numa_node 100 static inline void set_numa_node(int node) 101 { 102 this_cpu_write(numa_node, node); 103 } 104 #endif 105 106 #ifndef set_cpu_numa_node 107 static inline void set_cpu_numa_node(int cpu, int node) 108 { 109 per_cpu(numa_node, cpu) = node; 110 } 111 #endif 112 113 #else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */ 114 115 /* Returns the number of the current Node. */ 116 #ifndef numa_node_id 117 static inline int numa_node_id(void) 118 { 119 return cpu_to_node(raw_smp_processor_id()); 120 } 121 #endif 122 123 #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */ 124 125 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 126 127 /* 128 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. 129 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. 130 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem(). 131 */ 132 DECLARE_PER_CPU(int, _numa_mem_); 133 134 #ifndef set_numa_mem 135 static inline void set_numa_mem(int node) 136 { 137 this_cpu_write(_numa_mem_, node); 138 } 139 #endif 140 141 #ifndef numa_mem_id 142 /* Returns the number of the nearest Node with memory */ 143 static inline int numa_mem_id(void) 144 { 145 return raw_cpu_read(_numa_mem_); 146 } 147 #endif 148 149 #ifndef cpu_to_mem 150 static inline int cpu_to_mem(int cpu) 151 { 152 return per_cpu(_numa_mem_, cpu); 153 } 154 #endif 155 156 #ifndef set_cpu_numa_mem 157 static inline void set_cpu_numa_mem(int cpu, int node) 158 { 159 per_cpu(_numa_mem_, cpu) = node; 160 } 161 #endif 162 163 #else /* !CONFIG_HAVE_MEMORYLESS_NODES */ 164 165 #ifndef numa_mem_id 166 /* Returns the number of the nearest Node with memory */ 167 static inline int numa_mem_id(void) 168 { 169 return numa_node_id(); 170 } 171 #endif 172 173 #ifndef cpu_to_mem 174 static inline int cpu_to_mem(int cpu) 175 { 176 return cpu_to_node(cpu); 177 } 178 #endif 179 180 #endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */ 181 182 #ifndef topology_physical_package_id 183 #define topology_physical_package_id(cpu) ((void)(cpu), -1) 184 #endif 185 #ifndef topology_die_id 186 #define topology_die_id(cpu) ((void)(cpu), -1) 187 #endif 188 #ifndef topology_core_id 189 #define topology_core_id(cpu) ((void)(cpu), 0) 190 #endif 191 #ifndef topology_sibling_cpumask 192 #define topology_sibling_cpumask(cpu) cpumask_of(cpu) 193 #endif 194 #ifndef topology_core_cpumask 195 #define topology_core_cpumask(cpu) cpumask_of(cpu) 196 #endif 197 #ifndef topology_die_cpumask 198 #define topology_die_cpumask(cpu) cpumask_of(cpu) 199 #endif 200 201 #ifdef CONFIG_SCHED_SMT 202 static inline const struct cpumask *cpu_smt_mask(int cpu) 203 { 204 return topology_sibling_cpumask(cpu); 205 } 206 #endif 207 208 static inline const struct cpumask *cpu_cpu_mask(int cpu) 209 { 210 return cpumask_of_node(cpu_to_node(cpu)); 211 } 212 213 214 #endif /* _LINUX_TOPOLOGY_H */ 215