xref: /linux-6.15/include/linux/mempolicy.h (revision 87c2ce3b)
1 #ifndef _LINUX_MEMPOLICY_H
2 #define _LINUX_MEMPOLICY_H 1
3 
4 #include <linux/errno.h>
5 
6 /*
7  * NUMA memory policies for Linux.
8  * Copyright 2003,2004 Andi Kleen SuSE Labs
9  */
10 
11 /* Policies */
12 #define MPOL_DEFAULT	0
13 #define MPOL_PREFERRED	1
14 #define MPOL_BIND	2
15 #define MPOL_INTERLEAVE	3
16 
17 #define MPOL_MAX MPOL_INTERLEAVE
18 
19 /* Flags for get_mem_policy */
20 #define MPOL_F_NODE	(1<<0)	/* return next IL mode instead of node mask */
21 #define MPOL_F_ADDR	(1<<1)	/* look up vma using address */
22 
23 /* Flags for mbind */
24 #define MPOL_MF_STRICT	(1<<0)	/* Verify existing pages in the mapping */
25 #define MPOL_MF_MOVE	(1<<1)	/* Move pages owned by this process to conform to mapping */
26 #define MPOL_MF_MOVE_ALL (1<<2)	/* Move every page to conform to mapping */
27 #define MPOL_MF_INTERNAL (1<<3)	/* Internal flags start here */
28 
29 #ifdef __KERNEL__
30 
31 #include <linux/config.h>
32 #include <linux/mmzone.h>
33 #include <linux/slab.h>
34 #include <linux/rbtree.h>
35 #include <linux/spinlock.h>
36 #include <linux/nodemask.h>
37 
38 struct vm_area_struct;
39 
40 #ifdef CONFIG_NUMA
41 
42 /*
43  * Describe a memory policy.
44  *
45  * A mempolicy can be either associated with a process or with a VMA.
46  * For VMA related allocations the VMA policy is preferred, otherwise
47  * the process policy is used. Interrupts ignore the memory policy
48  * of the current process.
49  *
50  * Locking policy for interlave:
51  * In process context there is no locking because only the process accesses
52  * its own state. All vma manipulation is somewhat protected by a down_read on
53  * mmap_sem.
54  *
55  * Freeing policy:
56  * When policy is MPOL_BIND v.zonelist is kmalloc'ed and must be kfree'd.
57  * All other policies don't have any external state. mpol_free() handles this.
58  *
59  * Copying policy objects:
60  * For MPOL_BIND the zonelist must be always duplicated. mpol_clone() does this.
61  */
62 struct mempolicy {
63 	atomic_t refcnt;
64 	short policy; 	/* See MPOL_* above */
65 	union {
66 		struct zonelist  *zonelist;	/* bind */
67 		short 		 preferred_node; /* preferred */
68 		nodemask_t	 nodes;		/* interleave */
69 		/* undefined for default */
70 	} v;
71 	nodemask_t cpuset_mems_allowed;	/* mempolicy relative to these nodes */
72 };
73 
74 /*
75  * Support for managing mempolicy data objects (clone, copy, destroy)
76  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
77  */
78 
79 extern void __mpol_free(struct mempolicy *pol);
80 static inline void mpol_free(struct mempolicy *pol)
81 {
82 	if (pol)
83 		__mpol_free(pol);
84 }
85 
86 extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
87 static inline struct mempolicy *mpol_copy(struct mempolicy *pol)
88 {
89 	if (pol)
90 		pol = __mpol_copy(pol);
91 	return pol;
92 }
93 
94 #define vma_policy(vma) ((vma)->vm_policy)
95 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
96 
97 static inline void mpol_get(struct mempolicy *pol)
98 {
99 	if (pol)
100 		atomic_inc(&pol->refcnt);
101 }
102 
103 extern int __mpol_equal(struct mempolicy *a, struct mempolicy *b);
104 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
105 {
106 	if (a == b)
107 		return 1;
108 	return __mpol_equal(a, b);
109 }
110 #define vma_mpol_equal(a,b) mpol_equal(vma_policy(a), vma_policy(b))
111 
112 /* Could later add inheritance of the process policy here. */
113 
114 #define mpol_set_vma_default(vma) ((vma)->vm_policy = NULL)
115 
116 /*
117  * Tree of shared policies for a shared memory region.
118  * Maintain the policies in a pseudo mm that contains vmas. The vmas
119  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
120  * bytes, so that we can work with shared memory segments bigger than
121  * unsigned long.
122  */
123 
124 struct sp_node {
125 	struct rb_node nd;
126 	unsigned long start, end;
127 	struct mempolicy *policy;
128 };
129 
130 struct shared_policy {
131 	struct rb_root root;
132 	spinlock_t lock;
133 };
134 
135 static inline void mpol_shared_policy_init(struct shared_policy *info)
136 {
137 	info->root = RB_ROOT;
138 	spin_lock_init(&info->lock);
139 }
140 
141 int mpol_set_shared_policy(struct shared_policy *info,
142 				struct vm_area_struct *vma,
143 				struct mempolicy *new);
144 void mpol_free_shared_policy(struct shared_policy *p);
145 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
146 					    unsigned long idx);
147 
148 extern void numa_default_policy(void);
149 extern void numa_policy_init(void);
150 extern void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *new);
151 extern void mpol_rebind_task(struct task_struct *tsk,
152 					const nodemask_t *new);
153 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
154 #define set_cpuset_being_rebound(x) (cpuset_being_rebound = (x))
155 
156 #ifdef CONFIG_CPUSET
157 #define current_cpuset_is_being_rebound() \
158 				(cpuset_being_rebound == current->cpuset)
159 #else
160 #define current_cpuset_is_being_rebound() 0
161 #endif
162 
163 extern struct mempolicy default_policy;
164 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
165 		unsigned long addr);
166 
167 extern int policy_zone;
168 
169 static inline void check_highest_zone(int k)
170 {
171 	if (k > policy_zone)
172 		policy_zone = k;
173 }
174 
175 int do_migrate_pages(struct mm_struct *mm,
176 	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags);
177 
178 extern void *cpuset_being_rebound;	/* Trigger mpol_copy vma rebind */
179 
180 #else
181 
182 struct mempolicy {};
183 
184 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
185 {
186 	return 1;
187 }
188 #define vma_mpol_equal(a,b) 1
189 
190 #define mpol_set_vma_default(vma) do {} while(0)
191 
192 static inline void mpol_free(struct mempolicy *p)
193 {
194 }
195 
196 static inline void mpol_get(struct mempolicy *pol)
197 {
198 }
199 
200 static inline struct mempolicy *mpol_copy(struct mempolicy *old)
201 {
202 	return NULL;
203 }
204 
205 struct shared_policy {};
206 
207 static inline int mpol_set_shared_policy(struct shared_policy *info,
208 					struct vm_area_struct *vma,
209 					struct mempolicy *new)
210 {
211 	return -EINVAL;
212 }
213 
214 static inline void mpol_shared_policy_init(struct shared_policy *info)
215 {
216 }
217 
218 static inline void mpol_free_shared_policy(struct shared_policy *p)
219 {
220 }
221 
222 static inline struct mempolicy *
223 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
224 {
225 	return NULL;
226 }
227 
228 #define vma_policy(vma) NULL
229 #define vma_set_policy(vma, pol) do {} while(0)
230 
231 static inline void numa_policy_init(void)
232 {
233 }
234 
235 static inline void numa_default_policy(void)
236 {
237 }
238 
239 static inline void mpol_rebind_policy(struct mempolicy *pol,
240 					const nodemask_t *new)
241 {
242 }
243 
244 static inline void mpol_rebind_task(struct task_struct *tsk,
245 					const nodemask_t *new)
246 {
247 }
248 
249 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
250 {
251 }
252 
253 #define set_cpuset_being_rebound(x) do {} while (0)
254 
255 static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
256 		unsigned long addr)
257 {
258 	return NODE_DATA(0)->node_zonelists + gfp_zone(GFP_HIGHUSER);
259 }
260 
261 static inline int do_migrate_pages(struct mm_struct *mm,
262 			const nodemask_t *from_nodes,
263 			const nodemask_t *to_nodes, int flags)
264 {
265 	return 0;
266 }
267 
268 static inline void check_highest_zone(int k)
269 {
270 }
271 #endif /* CONFIG_NUMA */
272 #endif /* __KERNEL__ */
273 
274 #endif
275