1#ifndef _LINUX_CPUSET_H
2#define _LINUX_CPUSET_H
3/*
4 *  cpuset interface
5 *
6 *  Copyright (C) 2003 BULL SA
7 *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
8 *
9 */
10
11#include <linux/sched.h>
12#include <linux/cpumask.h>
13#include <linux/nodemask.h>
14#include <linux/mm.h>
15#include <linux/jump_label.h>
16
17#ifdef CONFIG_CPUSETS
18
19extern struct static_key cpusets_enabled_key;
20static inline bool cpusets_enabled(void)
21{
22	return static_key_false(&cpusets_enabled_key);
23}
24
25static inline int nr_cpusets(void)
26{
27	/* jump label reference count + the top-level cpuset */
28	return static_key_count(&cpusets_enabled_key) + 1;
29}
30
31static inline void cpuset_inc(void)
32{
33	static_key_slow_inc(&cpusets_enabled_key);
34}
35
36static inline void cpuset_dec(void)
37{
38	static_key_slow_dec(&cpusets_enabled_key);
39}
40
41extern int cpuset_init(void);
42extern void cpuset_init_smp(void);
43extern void cpuset_update_active_cpus(bool cpu_online);
44extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
45extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
46extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
47#define cpuset_current_mems_allowed (current->mems_allowed)
48void cpuset_init_current_mems_allowed(void);
49int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
50
51extern int __cpuset_node_allowed(int node, gfp_t gfp_mask);
52
53static inline int cpuset_node_allowed(int node, gfp_t gfp_mask)
54{
55	return nr_cpusets() <= 1 || __cpuset_node_allowed(node, gfp_mask);
56}
57
58static inline int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
59{
60	return cpuset_node_allowed(zone_to_nid(z), gfp_mask);
61}
62
63extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
64					  const struct task_struct *tsk2);
65
66#define cpuset_memory_pressure_bump() 				\
67	do {							\
68		if (cpuset_memory_pressure_enabled)		\
69			__cpuset_memory_pressure_bump();	\
70	} while (0)
71extern int cpuset_memory_pressure_enabled;
72extern void __cpuset_memory_pressure_bump(void);
73
74extern void cpuset_task_status_allowed(struct seq_file *m,
75					struct task_struct *task);
76extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
77			    struct pid *pid, struct task_struct *tsk);
78
79extern int cpuset_mem_spread_node(void);
80extern int cpuset_slab_spread_node(void);
81
82static inline int cpuset_do_page_mem_spread(void)
83{
84	return task_spread_page(current);
85}
86
87static inline int cpuset_do_slab_mem_spread(void)
88{
89	return task_spread_slab(current);
90}
91
92extern int current_cpuset_is_being_rebound(void);
93
94extern void rebuild_sched_domains(void);
95
96extern void cpuset_print_task_mems_allowed(struct task_struct *p);
97
98/*
99 * read_mems_allowed_begin is required when making decisions involving
100 * mems_allowed such as during page allocation. mems_allowed can be updated in
101 * parallel and depending on the new value an operation can fail potentially
102 * causing process failure. A retry loop with read_mems_allowed_begin and
103 * read_mems_allowed_retry prevents these artificial failures.
104 */
105static inline unsigned int read_mems_allowed_begin(void)
106{
107	return read_seqcount_begin(&current->mems_allowed_seq);
108}
109
110/*
111 * If this returns true, the operation that took place after
112 * read_mems_allowed_begin may have failed artificially due to a concurrent
113 * update of mems_allowed. It is up to the caller to retry the operation if
114 * appropriate.
115 */
116static inline bool read_mems_allowed_retry(unsigned int seq)
117{
118	return read_seqcount_retry(&current->mems_allowed_seq, seq);
119}
120
121static inline void set_mems_allowed(nodemask_t nodemask)
122{
123	unsigned long flags;
124
125	task_lock(current);
126	local_irq_save(flags);
127	write_seqcount_begin(&current->mems_allowed_seq);
128	current->mems_allowed = nodemask;
129	write_seqcount_end(&current->mems_allowed_seq);
130	local_irq_restore(flags);
131	task_unlock(current);
132}
133
134#else /* !CONFIG_CPUSETS */
135
136static inline bool cpusets_enabled(void) { return false; }
137
138static inline int cpuset_init(void) { return 0; }
139static inline void cpuset_init_smp(void) {}
140
141static inline void cpuset_update_active_cpus(bool cpu_online)
142{
143	partition_sched_domains(1, NULL, NULL);
144}
145
146static inline void cpuset_cpus_allowed(struct task_struct *p,
147				       struct cpumask *mask)
148{
149	cpumask_copy(mask, cpu_possible_mask);
150}
151
152static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
153{
154}
155
156static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
157{
158	return node_possible_map;
159}
160
161#define cpuset_current_mems_allowed (node_states[N_MEMORY])
162static inline void cpuset_init_current_mems_allowed(void) {}
163
164static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
165{
166	return 1;
167}
168
169static inline int cpuset_node_allowed(int node, gfp_t gfp_mask)
170{
171	return 1;
172}
173
174static inline int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
175{
176	return 1;
177}
178
179static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
180						 const struct task_struct *tsk2)
181{
182	return 1;
183}
184
185static inline void cpuset_memory_pressure_bump(void) {}
186
187static inline void cpuset_task_status_allowed(struct seq_file *m,
188						struct task_struct *task)
189{
190}
191
192static inline int cpuset_mem_spread_node(void)
193{
194	return 0;
195}
196
197static inline int cpuset_slab_spread_node(void)
198{
199	return 0;
200}
201
202static inline int cpuset_do_page_mem_spread(void)
203{
204	return 0;
205}
206
207static inline int cpuset_do_slab_mem_spread(void)
208{
209	return 0;
210}
211
212static inline int current_cpuset_is_being_rebound(void)
213{
214	return 0;
215}
216
217static inline void rebuild_sched_domains(void)
218{
219	partition_sched_domains(1, NULL, NULL);
220}
221
222static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
223{
224}
225
226static inline void set_mems_allowed(nodemask_t nodemask)
227{
228}
229
230static inline unsigned int read_mems_allowed_begin(void)
231{
232	return 0;
233}
234
235static inline bool read_mems_allowed_retry(unsigned int seq)
236{
237	return false;
238}
239
240#endif /* !CONFIG_CPUSETS */
241
242#endif /* _LINUX_CPUSET_H */
243