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>
37 #ifndef node_has_online_mem
38 #define node_has_online_mem(nid) (1)
42 #define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
45 #define for_each_node_with_cpus(node) \
46 for_each_online_node(node) \
47 if (nr_cpus_node(node))
49 int arch_update_cpu_topology(void);
51 /* Conform to ACPI 2.0 SLIT distance definitions */
52 #define LOCAL_DISTANCE 10
53 #define REMOTE_DISTANCE 20
55 #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
57 #ifndef RECLAIM_DISTANCE
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.
63 #define RECLAIM_DISTANCE 30
65 #ifndef PENALTY_FOR_NODE_WITH_CPUS
66 #define PENALTY_FOR_NODE_WITH_CPUS (1)
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
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.)
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?
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) { \
92 .imbalance_pct = 110, \
94 .flags = 1*SD_LOAD_BALANCE \
95 | 1*SD_BALANCE_NEWIDLE \
100 | 1*SD_SHARE_CPUPOWER \
101 | 0*SD_POWERSAVINGS_BALANCE \
102 | 1*SD_SHARE_PKG_RESOURCES \
104 | 0*SD_PREFER_SIBLING \
105 | arch_sd_sibling_asym_packing() \
107 .last_balance = jiffies, \
108 .balance_interval = 1, \
109 .smt_gain = 1178, /* 15% */ \
112 #endif /* CONFIG_SCHED_SMT */
114 #ifdef CONFIG_SCHED_MC
115 /* Common values for MC siblings. for now mostly derived from SD_CPU_INIT */
117 #define SD_MC_INIT (struct sched_domain) { \
121 .imbalance_pct = 125, \
122 .cache_nice_tries = 1, \
127 .flags = 1*SD_LOAD_BALANCE \
128 | 1*SD_BALANCE_NEWIDLE \
129 | 1*SD_BALANCE_EXEC \
130 | 1*SD_BALANCE_FORK \
131 | 0*SD_BALANCE_WAKE \
133 | 0*SD_PREFER_LOCAL \
134 | 0*SD_SHARE_CPUPOWER \
135 | 1*SD_SHARE_PKG_RESOURCES \
137 | sd_balance_for_mc_power() \
138 | sd_power_saving_flags() \
140 .last_balance = jiffies, \
141 .balance_interval = 1, \
144 #endif /* CONFIG_SCHED_MC */
146 /* Common values for CPUs */
148 #define SD_CPU_INIT (struct sched_domain) { \
152 .imbalance_pct = 125, \
153 .cache_nice_tries = 1, \
160 .flags = 1*SD_LOAD_BALANCE \
161 | 1*SD_BALANCE_NEWIDLE \
162 | 1*SD_BALANCE_EXEC \
163 | 1*SD_BALANCE_FORK \
164 | 0*SD_BALANCE_WAKE \
166 | 0*SD_PREFER_LOCAL \
167 | 0*SD_SHARE_CPUPOWER \
168 | 0*SD_SHARE_PKG_RESOURCES \
170 | sd_balance_for_package_power() \
171 | sd_power_saving_flags() \
173 .last_balance = jiffies, \
174 .balance_interval = 1, \
178 #ifdef CONFIG_SCHED_BOOK
180 #error Please define an appropriate SD_BOOK_INIT in include/asm/topology.h!!!
182 #endif /* CONFIG_SCHED_BOOK */
184 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
185 DECLARE_PER_CPU(int, numa_node);
188 /* Returns the number of the current Node. */
189 static inline int numa_node_id(void)
191 return __this_cpu_read(numa_node);
196 static inline int cpu_to_node(int cpu)
198 return per_cpu(numa_node, cpu);
202 #ifndef set_numa_node
203 static inline void set_numa_node(int node)
205 percpu_write(numa_node, node);
209 #ifndef set_cpu_numa_node
210 static inline void set_cpu_numa_node(int cpu, int node)
212 per_cpu(numa_node, cpu) = node;
216 #else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
218 /* Returns the number of the current Node. */
220 static inline int numa_node_id(void)
222 return cpu_to_node(raw_smp_processor_id());
226 #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
228 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
231 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
232 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
233 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
235 DECLARE_PER_CPU(int, _numa_mem_);
238 static inline void set_numa_mem(int node)
240 percpu_write(_numa_mem_, node);
245 /* Returns the number of the nearest Node with memory */
246 static inline int numa_mem_id(void)
248 return __this_cpu_read(_numa_mem_);
253 static inline int cpu_to_mem(int cpu)
255 return per_cpu(_numa_mem_, cpu);
259 #ifndef set_cpu_numa_mem
260 static inline void set_cpu_numa_mem(int cpu, int node)
262 per_cpu(_numa_mem_, cpu) = node;
266 #else /* !CONFIG_HAVE_MEMORYLESS_NODES */
269 /* Returns the number of the nearest Node with memory */
270 static inline int numa_mem_id(void)
272 return numa_node_id();
277 static inline int cpu_to_mem(int cpu)
279 return cpu_to_node(cpu);
283 #endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */
285 #ifndef topology_physical_package_id
286 #define topology_physical_package_id(cpu) ((void)(cpu), -1)
288 #ifndef topology_core_id
289 #define topology_core_id(cpu) ((void)(cpu), 0)
291 #ifndef topology_thread_cpumask
292 #define topology_thread_cpumask(cpu) cpumask_of(cpu)
294 #ifndef topology_core_cpumask
295 #define topology_core_cpumask(cpu) cpumask_of(cpu)
298 #endif /* _LINUX_TOPOLOGY_H */