lguest: documentation II: Guest
[linux-2.6] / 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/cpumask.h>
31 #include <linux/bitops.h>
32 #include <linux/mmzone.h>
33 #include <linux/smp.h>
34 #include <asm/topology.h>
35
36 #ifndef node_has_online_mem
37 #define node_has_online_mem(nid) (1)
38 #endif
39
40 #ifndef nr_cpus_node
41 #define nr_cpus_node(node)                                                      \
42         ({                                                                      \
43                 cpumask_t __tmp__;                                              \
44                 __tmp__ = node_to_cpumask(node);                                \
45                 cpus_weight(__tmp__);                                           \
46         })
47 #endif
48
49 #define for_each_node_with_cpus(node)                                           \
50         for_each_online_node(node)                                              \
51                 if (nr_cpus_node(node))
52
53 /* Conform to ACPI 2.0 SLIT distance definitions */
54 #define LOCAL_DISTANCE          10
55 #define REMOTE_DISTANCE         20
56 #ifndef node_distance
57 #define node_distance(from,to)  ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
58 #endif
59 #ifndef RECLAIM_DISTANCE
60 /*
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.
64  */
65 #define RECLAIM_DISTANCE 20
66 #endif
67 #ifndef PENALTY_FOR_NODE_WITH_CPUS
68 #define PENALTY_FOR_NODE_WITH_CPUS      (1)
69 #endif
70
71 /*
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
76  *
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.
81  */
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?
85  */
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,        \
91         .parent                 = NULL,                 \
92         .child                  = NULL,                 \
93         .groups                 = NULL,                 \
94         .min_interval           = 1,                    \
95         .max_interval           = 2,                    \
96         .busy_factor            = 64,                   \
97         .imbalance_pct          = 110,                  \
98         .cache_nice_tries       = 0,                    \
99         .busy_idx               = 0,                    \
100         .idle_idx               = 0,                    \
101         .newidle_idx            = 0,                    \
102         .wake_idx               = 0,                    \
103         .forkexec_idx           = 0,                    \
104         .flags                  = SD_LOAD_BALANCE       \
105                                 | SD_BALANCE_NEWIDLE    \
106                                 | SD_BALANCE_EXEC       \
107                                 | SD_WAKE_AFFINE        \
108                                 | SD_WAKE_IDLE          \
109                                 | SD_SHARE_CPUPOWER,    \
110         .last_balance           = jiffies,              \
111         .balance_interval       = 1,                    \
112         .nr_balance_failed      = 0,                    \
113 }
114 #endif
115 #endif /* CONFIG_SCHED_SMT */
116
117 #ifdef CONFIG_SCHED_MC
118 /* Common values for MC siblings. for now mostly derived from SD_CPU_INIT */
119 #ifndef SD_MC_INIT
120 #define SD_MC_INIT (struct sched_domain) {              \
121         .span                   = CPU_MASK_NONE,        \
122         .parent                 = NULL,                 \
123         .child                  = NULL,                 \
124         .groups                 = NULL,                 \
125         .min_interval           = 1,                    \
126         .max_interval           = 4,                    \
127         .busy_factor            = 64,                   \
128         .imbalance_pct          = 125,                  \
129         .cache_nice_tries       = 1,                    \
130         .busy_idx               = 2,                    \
131         .idle_idx               = 0,                    \
132         .newidle_idx            = 0,                    \
133         .wake_idx               = 1,                    \
134         .forkexec_idx           = 1,                    \
135         .flags                  = SD_LOAD_BALANCE       \
136                                 | SD_BALANCE_NEWIDLE    \
137                                 | SD_BALANCE_EXEC       \
138                                 | SD_WAKE_AFFINE        \
139                                 | SD_WAKE_IDLE          \
140                                 | SD_SHARE_PKG_RESOURCES\
141                                 | BALANCE_FOR_MC_POWER, \
142         .last_balance           = jiffies,              \
143         .balance_interval       = 1,                    \
144         .nr_balance_failed      = 0,                    \
145 }
146 #endif
147 #endif /* CONFIG_SCHED_MC */
148
149 /* Common values for CPUs */
150 #ifndef SD_CPU_INIT
151 #define SD_CPU_INIT (struct sched_domain) {             \
152         .span                   = CPU_MASK_NONE,        \
153         .parent                 = NULL,                 \
154         .child                  = NULL,                 \
155         .groups                 = NULL,                 \
156         .min_interval           = 1,                    \
157         .max_interval           = 4,                    \
158         .busy_factor            = 64,                   \
159         .imbalance_pct          = 125,                  \
160         .cache_nice_tries       = 1,                    \
161         .busy_idx               = 2,                    \
162         .idle_idx               = 0,                    \
163         .newidle_idx            = 0,                    \
164         .wake_idx               = 1,                    \
165         .forkexec_idx           = 1,                    \
166         .flags                  = SD_LOAD_BALANCE       \
167                                 | SD_BALANCE_NEWIDLE    \
168                                 | SD_BALANCE_EXEC       \
169                                 | SD_WAKE_AFFINE        \
170                                 | SD_WAKE_IDLE          \
171                                 | BALANCE_FOR_PKG_POWER,\
172         .last_balance           = jiffies,              \
173         .balance_interval       = 1,                    \
174         .nr_balance_failed      = 0,                    \
175 }
176 #endif
177
178 /* sched_domains SD_ALLNODES_INIT for NUMA machines */
179 #define SD_ALLNODES_INIT (struct sched_domain) {        \
180         .span                   = CPU_MASK_NONE,        \
181         .parent                 = NULL,                 \
182         .child                  = NULL,                 \
183         .groups                 = NULL,                 \
184         .min_interval           = 64,                   \
185         .max_interval           = 64*num_online_cpus(), \
186         .busy_factor            = 128,                  \
187         .imbalance_pct          = 133,                  \
188         .cache_hot_time         = (10*1000000),         \
189         .cache_nice_tries       = 1,                    \
190         .busy_idx               = 3,                    \
191         .idle_idx               = 3,                    \
192         .newidle_idx            = 0, /* unused */       \
193         .wake_idx               = 0, /* unused */       \
194         .forkexec_idx           = 0, /* unused */       \
195         .flags                  = SD_LOAD_BALANCE       \
196                                 | SD_SERIALIZE, \
197         .last_balance           = jiffies,              \
198         .balance_interval       = 64,                   \
199         .nr_balance_failed      = 0,                    \
200 }
201
202 #ifdef CONFIG_NUMA
203 #ifndef SD_NODE_INIT
204 #error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
205 #endif
206 #endif /* CONFIG_NUMA */
207
208 #endif /* _LINUX_TOPOLOGY_H */