include/linux/topology.h

   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 <colpatch@us.ibm.com>
  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 #define DISTANCE_BITS           8
  52 #ifndef node_distance
  53 #define node_distance(from,to)  ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
  54 #endif
  55 #ifndef RECLAIM_DISTANCE
  56 /*
  57  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
  58  * (in whatever arch specific measurement units returned by node_distance())
  59  * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
  60  * on nodes within this distance.
  61  */
  62 #define RECLAIM_DISTANCE 30
  63 #endif
  64
  65 /*
  66  * The following tunable allows platforms to override the default node
  67  * reclaim distance (RECLAIM_DISTANCE) if remote memory accesses are
  68  * sufficiently fast that the default value actually hurts
  69  * performance.
  70  *
  71  * AMD EPYC machines use this because even though the 2-hop distance
  72  * is 32 (3.2x slower than a local memory access) performance actually
  73  * *improves* if allowed to reclaim memory and load balance tasks
  74  * between NUMA nodes 2-hops apart.
  75  */
  76 extern int __read_mostly node_reclaim_distance;
  77
  78 #ifndef PENALTY_FOR_NODE_WITH_CPUS
  79 #define PENALTY_FOR_NODE_WITH_CPUS      (1)
  80 #endif
  81
  82 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
  83 DECLARE_PER_CPU(int, numa_node);
  84
  85 #ifndef numa_node_id
  86 /* Returns the number of the current Node. */
  87 static inline int numa_node_id(void)
  88 {
  89         return raw_cpu_read(numa_node);
  90 }
  91 #endif
  92
  93 #ifndef cpu_to_node
  94 static inline int cpu_to_node(int cpu)
  95 {
  96         return per_cpu(numa_node, cpu);
  97 }
  98 #endif
  99
 100 #ifndef set_numa_node
 101 static inline void set_numa_node(int node)
 102 {
 103         this_cpu_write(numa_node, node);
 104 }
 105 #endif
 106
 107 #ifndef set_cpu_numa_node
 108 static inline void set_cpu_numa_node(int cpu, int node)
 109 {
 110         per_cpu(numa_node, cpu) = node;
 111 }
 112 #endif
 113
 114 #else   /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
 115
 116 /* Returns the number of the current Node. */
 117 #ifndef numa_node_id
 118 static inline int numa_node_id(void)
 119 {
 120         return cpu_to_node(raw_smp_processor_id());
 121 }
 122 #endif
 123
 124 #endif  /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
 125
 126 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
 127
 128 /*
 129  * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
 130  * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
 131  * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
 132  */
 133 DECLARE_PER_CPU(int, _numa_mem_);
 134
 135 #ifndef set_numa_mem
 136 static inline void set_numa_mem(int node)
 137 {
 138         this_cpu_write(_numa_mem_, node);
 139 }
 140 #endif
 141
 142 #ifndef numa_mem_id
 143 /* Returns the number of the nearest Node with memory */
 144 static inline int numa_mem_id(void)
 145 {
 146         return raw_cpu_read(_numa_mem_);
 147 }
 148 #endif
 149
 150 #ifndef cpu_to_mem
 151 static inline int cpu_to_mem(int cpu)
 152 {
 153         return per_cpu(_numa_mem_, cpu);
 154 }
 155 #endif
 156
 157 #ifndef set_cpu_numa_mem
 158 static inline void set_cpu_numa_mem(int cpu, int node)
 159 {
 160         per_cpu(_numa_mem_, cpu) = node;
 161 }
 162 #endif
 163
 164 #else   /* !CONFIG_HAVE_MEMORYLESS_NODES */
 165
 166 #ifndef numa_mem_id
 167 /* Returns the number of the nearest Node with memory */
 168 static inline int numa_mem_id(void)
 169 {
 170         return numa_node_id();
 171 }
 172 #endif
 173
 174 #ifndef cpu_to_mem
 175 static inline int cpu_to_mem(int cpu)
 176 {
 177         return cpu_to_node(cpu);
 178 }
 179 #endif
 180
 181 #endif  /* [!]CONFIG_HAVE_MEMORYLESS_NODES */
 182
 183 #ifndef topology_physical_package_id
 184 #define topology_physical_package_id(cpu)       ((void)(cpu), -1)
 185 #endif
 186 #ifndef topology_die_id
 187 #define topology_die_id(cpu)                    ((void)(cpu), -1)
 188 #endif
 189 #ifndef topology_core_id
 190 #define topology_core_id(cpu)                   ((void)(cpu), 0)
 191 #endif
 192 #ifndef topology_sibling_cpumask
 193 #define topology_sibling_cpumask(cpu)           cpumask_of(cpu)
 194 #endif
 195 #ifndef topology_core_cpumask
 196 #define topology_core_cpumask(cpu)              cpumask_of(cpu)
 197 #endif
 198 #ifndef topology_die_cpumask
 199 #define topology_die_cpumask(cpu)               cpumask_of(cpu)
 200 #endif
 201
 202 #if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
 203 static inline const struct cpumask *cpu_smt_mask(int cpu)
 204 {
 205         return topology_sibling_cpumask(cpu);
 206 }
 207 #endif
 208
 209 static inline const struct cpumask *cpu_cpu_mask(int cpu)
 210 {
 211         return cpumask_of_node(cpu_to_node(cpu));
 212 }
 213
 214
 215 #endif /* _LINUX_TOPOLOGY_H */