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
46int 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 */
76extern 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
83DECLARE_PER_CPU(int, numa_node);
84
85#ifndef numa_node_id
86/* Returns the number of the current Node. */
87static inline int numa_node_id(void)
88{
89 return raw_cpu_read(numa_node);
90}
91#endif
92
93#ifndef cpu_to_node
94static inline int cpu_to_node(int cpu)
95{
96 return per_cpu(numa_node, cpu);
97}
98#endif
99
100#ifndef set_numa_node
101static 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
108static 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
118static 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 */
133DECLARE_PER_CPU(int, _numa_mem_);
134
135#ifndef set_numa_mem
136static 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 */
144static inline int numa_mem_id(void)
145{
146 return raw_cpu_read(_numa_mem_);
147}
148#endif
149
150#ifndef cpu_to_mem
151static 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
158static 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 */
168static inline int numa_mem_id(void)
169{
170 return numa_node_id();
171}
172#endif
173
174#ifndef cpu_to_mem
175static 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#if defined(topology_die_id) && defined(topology_die_cpumask)
184#define TOPOLOGY_DIE_SYSFS
185#endif
186#if defined(topology_cluster_id) && defined(topology_cluster_cpumask)
187#define TOPOLOGY_CLUSTER_SYSFS
188#endif
189#if defined(topology_book_id) && defined(topology_book_cpumask)
190#define TOPOLOGY_BOOK_SYSFS
191#endif
192#if defined(topology_drawer_id) && defined(topology_drawer_cpumask)
193#define TOPOLOGY_DRAWER_SYSFS
194#endif
195
196#ifndef topology_physical_package_id
197#define topology_physical_package_id(cpu) ((void)(cpu), -1)
198#endif
199#ifndef topology_die_id
200#define topology_die_id(cpu) ((void)(cpu), -1)
201#endif
202#ifndef topology_cluster_id
203#define topology_cluster_id(cpu) ((void)(cpu), -1)
204#endif
205#ifndef topology_core_id
206#define topology_core_id(cpu) ((void)(cpu), 0)
207#endif
208#ifndef topology_book_id
209#define topology_book_id(cpu) ((void)(cpu), -1)
210#endif
211#ifndef topology_drawer_id
212#define topology_drawer_id(cpu) ((void)(cpu), -1)
213#endif
214#ifndef topology_ppin
215#define topology_ppin(cpu) ((void)(cpu), 0ull)
216#endif
217#ifndef topology_sibling_cpumask
218#define topology_sibling_cpumask(cpu) cpumask_of(cpu)
219#endif
220#ifndef topology_core_cpumask
221#define topology_core_cpumask(cpu) cpumask_of(cpu)
222#endif
223#ifndef topology_cluster_cpumask
224#define topology_cluster_cpumask(cpu) cpumask_of(cpu)
225#endif
226#ifndef topology_die_cpumask
227#define topology_die_cpumask(cpu) cpumask_of(cpu)
228#endif
229#ifndef topology_book_cpumask
230#define topology_book_cpumask(cpu) cpumask_of(cpu)
231#endif
232#ifndef topology_drawer_cpumask
233#define topology_drawer_cpumask(cpu) cpumask_of(cpu)
234#endif
235
236#if defined(CONFIG_SCHED_SMT) && !defined(cpu_smt_mask)
237static inline const struct cpumask *cpu_smt_mask(int cpu)
238{
239 return topology_sibling_cpumask(cpu);
240}
241#endif
242
243static inline const struct cpumask *cpu_cpu_mask(int cpu)
244{
245 return cpumask_of_node(cpu_to_node(cpu));
246}
247
248
249#endif /* _LINUX_TOPOLOGY_H */
250

source code of linux/include/linux/topology.h