2 * include/linux/topology.h
4 * Written by: Matthew Dobson, IBM Corporation
6 * Copyright (C) 2002, IBM Corp.
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.
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
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.
25 * Send feedback to <colpatch@us.ibm.com>
27 #ifndef _LINUX_TOPOLOGY_H
28 #define _LINUX_TOPOLOGY_H
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>
38 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
41 #define for_each_node_with_cpus(node) \
42 for_each_online_node(node) \
43 if (nr_cpus_node(node))
45 int arch_update_cpu_topology(void);
47 /* Conform to ACPI 2.0 SLIT distance definitions */
48 #define LOCAL_DISTANCE 10
49 #define REMOTE_DISTANCE 20
50 #define DISTANCE_BITS 8
52 #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
54 #ifndef RECLAIM_DISTANCE
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.
61 #define RECLAIM_DISTANCE 30
63 #ifndef PENALTY_FOR_NODE_WITH_CPUS
64 #define PENALTY_FOR_NODE_WITH_CPUS (1)
67 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
68 DECLARE_PER_CPU(int, numa_node);
71 /* Returns the number of the current Node. */
72 static inline int numa_node_id(void)
74 return raw_cpu_read(numa_node);
79 static inline int cpu_to_node(int cpu)
81 return per_cpu(numa_node, cpu);
86 static inline void set_numa_node(int node)
88 this_cpu_write(numa_node, node);
92 #ifndef set_cpu_numa_node
93 static inline void set_cpu_numa_node(int cpu, int node)
95 per_cpu(numa_node, cpu) = node;
99 #else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
101 /* Returns the number of the current Node. */
103 static inline int numa_node_id(void)
105 return cpu_to_node(raw_smp_processor_id());
109 #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
111 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
114 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
115 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
116 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
118 DECLARE_PER_CPU(int, _numa_mem_);
119 extern int _node_numa_mem_[MAX_NUMNODES];
122 static inline void set_numa_mem(int node)
124 this_cpu_write(_numa_mem_, node);
125 _node_numa_mem_[numa_node_id()] = node;
129 #ifndef node_to_mem_node
130 static inline int node_to_mem_node(int node)
132 return _node_numa_mem_[node];
137 /* Returns the number of the nearest Node with memory */
138 static inline int numa_mem_id(void)
140 return raw_cpu_read(_numa_mem_);
145 static inline int cpu_to_mem(int cpu)
147 return per_cpu(_numa_mem_, cpu);
151 #ifndef set_cpu_numa_mem
152 static inline void set_cpu_numa_mem(int cpu, int node)
154 per_cpu(_numa_mem_, cpu) = node;
155 _node_numa_mem_[cpu_to_node(cpu)] = node;
159 #else /* !CONFIG_HAVE_MEMORYLESS_NODES */
162 /* Returns the number of the nearest Node with memory */
163 static inline int numa_mem_id(void)
165 return numa_node_id();
169 #ifndef node_to_mem_node
170 static inline int node_to_mem_node(int node)
177 static inline int cpu_to_mem(int cpu)
179 return cpu_to_node(cpu);
183 #endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */
185 #ifndef topology_physical_package_id
186 #define topology_physical_package_id(cpu) ((void)(cpu), -1)
188 #ifndef topology_core_id
189 #define topology_core_id(cpu) ((void)(cpu), 0)
191 #ifndef topology_sibling_cpumask
192 #define topology_sibling_cpumask(cpu) cpumask_of(cpu)
194 #ifndef topology_core_cpumask
195 #define topology_core_cpumask(cpu) cpumask_of(cpu)
198 #ifdef CONFIG_SCHED_SMT
199 static inline const struct cpumask *cpu_smt_mask(int cpu)
201 return topology_sibling_cpumask(cpu);
205 static inline const struct cpumask *cpu_cpu_mask(int cpu)
207 return cpumask_of_node(cpu_to_node(cpu));
211 #endif /* _LINUX_TOPOLOGY_H */