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 <asm/topology.h>
36 #ifndef node_has_online_mem
37 #define node_has_online_mem(nid) (1)
41 #define nr_cpus_node(node) \
44 __tmp__ = node_to_cpumask(node); \
45 cpus_weight(__tmp__); \
49 #define for_each_node_with_cpus(node) \
50 for_each_online_node(node) \
51 if (nr_cpus_node(node))
54 /* Conform to ACPI 2.0 SLIT distance definitions */
55 #define LOCAL_DISTANCE 10
56 #define REMOTE_DISTANCE 20
57 #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
59 #ifndef RECLAIM_DISTANCE
61 * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
62 * (in whatever arch specific measurement units returned by node_distance())
63 * then switch on zone reclaim on boot.
65 #define RECLAIM_DISTANCE 20
67 #ifndef PENALTY_FOR_NODE_WITH_CPUS
68 #define PENALTY_FOR_NODE_WITH_CPUS (1)
72 * Below are the 3 major initializers used in building sched_domains:
73 * SD_SIBLING_INIT, for SMT domains
74 * SD_CPU_INIT, for SMP domains
75 * SD_NODE_INIT, for NUMA domains
77 * Any architecture that cares to do any tuning to these values should do so
78 * by defining their own arch-specific initializer in include/asm/topology.h.
79 * A definition there will automagically override these default initializers
80 * and allow arch-specific performance tuning of sched_domains.
82 #ifdef CONFIG_SCHED_SMT
83 /* MCD - Do we really need this? It is always on if CONFIG_SCHED_SMT is,
84 * so can't we drop this in favor of CONFIG_SCHED_SMT?
86 #define ARCH_HAS_SCHED_WAKE_IDLE
87 /* Common values for SMT siblings */
88 #ifndef SD_SIBLING_INIT
89 #define SD_SIBLING_INIT (struct sched_domain) { \
90 .span = CPU_MASK_NONE, \
96 .imbalance_pct = 110, \
97 .cache_nice_tries = 0, \
104 .flags = SD_LOAD_BALANCE \
105 | SD_BALANCE_NEWIDLE \
109 | SD_SHARE_CPUPOWER, \
110 .last_balance = jiffies, \
111 .balance_interval = 1, \
112 .nr_balance_failed = 0, \
115 #endif /* CONFIG_SCHED_SMT */
117 /* Common values for CPUs */
119 #define SD_CPU_INIT (struct sched_domain) { \
120 .span = CPU_MASK_NONE, \
126 .imbalance_pct = 125, \
127 .cache_nice_tries = 1, \
128 .per_cpu_gain = 100, \
134 .flags = SD_LOAD_BALANCE \
135 | SD_BALANCE_NEWIDLE \
138 .last_balance = jiffies, \
139 .balance_interval = 1, \
140 .nr_balance_failed = 0, \
144 /* sched_domains SD_ALLNODES_INIT for NUMA machines */
145 #define SD_ALLNODES_INIT (struct sched_domain) { \
146 .span = CPU_MASK_NONE, \
149 .min_interval = 64, \
150 .max_interval = 64*num_online_cpus(), \
151 .busy_factor = 128, \
152 .imbalance_pct = 133, \
153 .cache_hot_time = (10*1000000), \
154 .cache_nice_tries = 1, \
157 .newidle_idx = 0, /* unused */ \
158 .wake_idx = 0, /* unused */ \
159 .forkexec_idx = 0, /* unused */ \
160 .per_cpu_gain = 100, \
161 .flags = SD_LOAD_BALANCE, \
162 .last_balance = jiffies, \
163 .balance_interval = 64, \
164 .nr_balance_failed = 0, \
167 #ifdef CONFIG_SCHED_MC
169 /* for now its same as SD_CPU_INIT.
170 * TBD: Tune Domain parameters!
172 #define SD_MC_INIT SD_CPU_INIT
178 #error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
180 #endif /* CONFIG_NUMA */
182 #endif /* _LINUX_TOPOLOGY_H */