xref: /linux-6.15/include/linux/mempolicy.h (revision a1e58bbd)
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 #define MPOL_F_MEMS_ALLOWED (1<<2) /* return allowed memories */
23 
24 /* Flags for mbind */
25 #define MPOL_MF_STRICT	(1<<0)	/* Verify existing pages in the mapping */
26 #define MPOL_MF_MOVE	(1<<1)	/* Move pages owned by this process to conform to mapping */
27 #define MPOL_MF_MOVE_ALL (1<<2)	/* Move every page to conform to mapping */
28 #define MPOL_MF_INTERNAL (1<<3)	/* Internal flags start here */
29 
30 #ifdef __KERNEL__
31 
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 struct mm_struct;
40 
41 #ifdef CONFIG_NUMA
42 
43 /*
44  * Describe a memory policy.
45  *
46  * A mempolicy can be either associated with a process or with a VMA.
47  * For VMA related allocations the VMA policy is preferred, otherwise
48  * the process policy is used. Interrupts ignore the memory policy
49  * of the current process.
50  *
51  * Locking policy for interlave:
52  * In process context there is no locking because only the process accesses
53  * its own state. All vma manipulation is somewhat protected by a down_read on
54  * mmap_sem.
55  *
56  * Freeing policy:
57  * When policy is MPOL_BIND v.zonelist is kmalloc'ed and must be kfree'd.
58  * All other policies don't have any external state. mpol_free() handles this.
59  *
60  * Copying policy objects:
61  * For MPOL_BIND the zonelist must be always duplicated. mpol_clone() does this.
62  */
63 struct mempolicy {
64 	atomic_t refcnt;
65 	short policy; 	/* See MPOL_* above */
66 	union {
67 		struct zonelist  *zonelist;	/* bind */
68 		short 		 preferred_node; /* preferred */
69 		nodemask_t	 nodes;		/* interleave */
70 		/* undefined for default */
71 	} v;
72 	nodemask_t cpuset_mems_allowed;	/* mempolicy relative to these nodes */
73 };
74 
75 /*
76  * Support for managing mempolicy data objects (clone, copy, destroy)
77  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
78  */
79 
80 extern void __mpol_free(struct mempolicy *pol);
81 static inline void mpol_free(struct mempolicy *pol)
82 {
83 	if (pol)
84 		__mpol_free(pol);
85 }
86 
87 extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
88 static inline struct mempolicy *mpol_copy(struct mempolicy *pol)
89 {
90 	if (pol)
91 		pol = __mpol_copy(pol);
92 	return pol;
93 }
94 
95 #define vma_policy(vma) ((vma)->vm_policy)
96 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
97 
98 static inline void mpol_get(struct mempolicy *pol)
99 {
100 	if (pol)
101 		atomic_inc(&pol->refcnt);
102 }
103 
104 extern int __mpol_equal(struct mempolicy *a, struct mempolicy *b);
105 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
106 {
107 	if (a == b)
108 		return 1;
109 	return __mpol_equal(a, b);
110 }
111 #define vma_mpol_equal(a,b) mpol_equal(vma_policy(a), vma_policy(b))
112 
113 /* Could later add inheritance of the process policy here. */
114 
115 #define mpol_set_vma_default(vma) ((vma)->vm_policy = NULL)
116 
117 /*
118  * Tree of shared policies for a shared memory region.
119  * Maintain the policies in a pseudo mm that contains vmas. The vmas
120  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
121  * bytes, so that we can work with shared memory segments bigger than
122  * unsigned long.
123  */
124 
125 struct sp_node {
126 	struct rb_node nd;
127 	unsigned long start, end;
128 	struct mempolicy *policy;
129 };
130 
131 struct shared_policy {
132 	struct rb_root root;
133 	spinlock_t lock;
134 };
135 
136 void mpol_shared_policy_init(struct shared_policy *info, int policy,
137 				nodemask_t *nodes);
138 int mpol_set_shared_policy(struct shared_policy *info,
139 				struct vm_area_struct *vma,
140 				struct mempolicy *new);
141 void mpol_free_shared_policy(struct shared_policy *p);
142 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
143 					    unsigned long idx);
144 
145 extern void numa_default_policy(void);
146 extern void numa_policy_init(void);
147 extern void mpol_rebind_task(struct task_struct *tsk,
148 					const nodemask_t *new);
149 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
150 extern void mpol_fix_fork_child_flag(struct task_struct *p);
151 
152 extern struct mempolicy default_policy;
153 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
154 		unsigned long addr, gfp_t gfp_flags, struct mempolicy **mpol);
155 extern unsigned slab_node(struct mempolicy *policy);
156 
157 extern enum zone_type policy_zone;
158 
159 static inline void check_highest_zone(enum zone_type k)
160 {
161 	if (k > policy_zone && k != ZONE_MOVABLE)
162 		policy_zone = k;
163 }
164 
165 int do_migrate_pages(struct mm_struct *mm,
166 	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags);
167 
168 #else
169 
170 struct mempolicy {};
171 
172 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
173 {
174 	return 1;
175 }
176 #define vma_mpol_equal(a,b) 1
177 
178 #define mpol_set_vma_default(vma) do {} while(0)
179 
180 static inline void mpol_free(struct mempolicy *p)
181 {
182 }
183 
184 static inline void mpol_get(struct mempolicy *pol)
185 {
186 }
187 
188 static inline struct mempolicy *mpol_copy(struct mempolicy *old)
189 {
190 	return NULL;
191 }
192 
193 struct shared_policy {};
194 
195 static inline int mpol_set_shared_policy(struct shared_policy *info,
196 					struct vm_area_struct *vma,
197 					struct mempolicy *new)
198 {
199 	return -EINVAL;
200 }
201 
202 static inline void mpol_shared_policy_init(struct shared_policy *info,
203 					int policy, nodemask_t *nodes)
204 {
205 }
206 
207 static inline void mpol_free_shared_policy(struct shared_policy *p)
208 {
209 }
210 
211 static inline struct mempolicy *
212 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
213 {
214 	return NULL;
215 }
216 
217 #define vma_policy(vma) NULL
218 #define vma_set_policy(vma, pol) do {} while(0)
219 
220 static inline void numa_policy_init(void)
221 {
222 }
223 
224 static inline void numa_default_policy(void)
225 {
226 }
227 
228 static inline void mpol_rebind_task(struct task_struct *tsk,
229 					const nodemask_t *new)
230 {
231 }
232 
233 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
234 {
235 }
236 
237 static inline void mpol_fix_fork_child_flag(struct task_struct *p)
238 {
239 }
240 
241 static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
242  		unsigned long addr, gfp_t gfp_flags, struct mempolicy **mpol)
243 {
244 	return NODE_DATA(0)->node_zonelists + gfp_zone(gfp_flags);
245 }
246 
247 static inline int do_migrate_pages(struct mm_struct *mm,
248 			const nodemask_t *from_nodes,
249 			const nodemask_t *to_nodes, int flags)
250 {
251 	return 0;
252 }
253 
254 static inline void check_highest_zone(int k)
255 {
256 }
257 #endif /* CONFIG_NUMA */
258 #endif /* __KERNEL__ */
259 
260 #endif
261