1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * NUMA memory policies for Linux.
4 * Copyright 2003,2004 Andi Kleen SuSE Labs
5 */
6#ifndef _LINUX_MEMPOLICY_H
7#define _LINUX_MEMPOLICY_H 1
8
9#include <linux/sched.h>
10#include <linux/mmzone.h>
11#include <linux/slab.h>
12#include <linux/rbtree.h>
13#include <linux/spinlock.h>
14#include <linux/nodemask.h>
15#include <linux/pagemap.h>
16#include <uapi/linux/mempolicy.h>
17
18struct mm_struct;
19
20#define NO_INTERLEAVE_INDEX (-1UL) /* use task il_prev for interleaving */
21
22#ifdef CONFIG_NUMA
23
24/*
25 * Describe a memory policy.
26 *
27 * A mempolicy can be either associated with a process or with a VMA.
28 * For VMA related allocations the VMA policy is preferred, otherwise
29 * the process policy is used. Interrupts ignore the memory policy
30 * of the current process.
31 *
32 * Locking policy for interleave:
33 * In process context there is no locking because only the process accesses
34 * its own state. All vma manipulation is somewhat protected by a down_read on
35 * mmap_lock.
36 *
37 * Freeing policy:
38 * Mempolicy objects are reference counted. A mempolicy will be freed when
39 * mpol_put() decrements the reference count to zero.
40 *
41 * Duplicating policy objects:
42 * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
43 * to the new storage. The reference count of the new object is initialized
44 * to 1, representing the caller of mpol_dup().
45 */
46struct mempolicy {
47 atomic_t refcnt;
48 unsigned short mode; /* See MPOL_* above */
49 unsigned short flags; /* See set_mempolicy() MPOL_F_* above */
50 nodemask_t nodes; /* interleave/bind/perfer */
51 int home_node; /* Home node to use for MPOL_BIND and MPOL_PREFERRED_MANY */
52
53 union {
54 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
55 nodemask_t user_nodemask; /* nodemask passed by user */
56 } w;
57};
58
59/*
60 * Support for managing mempolicy data objects (clone, copy, destroy)
61 * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
62 */
63
64extern void __mpol_put(struct mempolicy *pol);
65static inline void mpol_put(struct mempolicy *pol)
66{
67 if (pol)
68 __mpol_put(pol);
69}
70
71/*
72 * Does mempolicy pol need explicit unref after use?
73 * Currently only needed for shared policies.
74 */
75static inline int mpol_needs_cond_ref(struct mempolicy *pol)
76{
77 return (pol && (pol->flags & MPOL_F_SHARED));
78}
79
80static inline void mpol_cond_put(struct mempolicy *pol)
81{
82 if (mpol_needs_cond_ref(pol))
83 __mpol_put(pol);
84}
85
86extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
87static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
88{
89 if (pol)
90 pol = __mpol_dup(pol);
91 return pol;
92}
93
94static inline void mpol_get(struct mempolicy *pol)
95{
96 if (pol)
97 atomic_inc(v: &pol->refcnt);
98}
99
100extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
101static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
102{
103 if (a == b)
104 return true;
105 return __mpol_equal(a, b);
106}
107
108/*
109 * Tree of shared policies for a shared memory region.
110 */
111struct shared_policy {
112 struct rb_root root;
113 rwlock_t lock;
114};
115struct sp_node {
116 struct rb_node nd;
117 pgoff_t start, end;
118 struct mempolicy *policy;
119};
120
121int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
122void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
123int mpol_set_shared_policy(struct shared_policy *sp,
124 struct vm_area_struct *vma, struct mempolicy *mpol);
125void mpol_free_shared_policy(struct shared_policy *sp);
126struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
127 pgoff_t idx);
128
129struct mempolicy *get_task_policy(struct task_struct *p);
130struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
131 unsigned long addr, pgoff_t *ilx);
132struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
133 unsigned long addr, int order, pgoff_t *ilx);
134bool vma_policy_mof(struct vm_area_struct *vma);
135
136extern void numa_default_policy(void);
137extern void numa_policy_init(void);
138extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new);
139extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
140
141extern int huge_node(struct vm_area_struct *vma,
142 unsigned long addr, gfp_t gfp_flags,
143 struct mempolicy **mpol, nodemask_t **nodemask);
144extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
145extern bool mempolicy_in_oom_domain(struct task_struct *tsk,
146 const nodemask_t *mask);
147extern unsigned int mempolicy_slab_node(void);
148
149extern enum zone_type policy_zone;
150
151static inline void check_highest_zone(enum zone_type k)
152{
153 if (k > policy_zone && k != ZONE_MOVABLE)
154 policy_zone = k;
155}
156
157int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
158 const nodemask_t *to, int flags);
159
160
161#ifdef CONFIG_TMPFS
162extern int mpol_parse_str(char *str, struct mempolicy **mpol);
163#endif
164
165extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
166
167/* Check if a vma is migratable */
168extern bool vma_migratable(struct vm_area_struct *vma);
169
170int mpol_misplaced(struct folio *, struct vm_area_struct *, unsigned long);
171extern void mpol_put_task_policy(struct task_struct *);
172
173static inline bool mpol_is_preferred_many(struct mempolicy *pol)
174{
175 return (pol->mode == MPOL_PREFERRED_MANY);
176}
177
178extern bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone);
179
180#else
181
182struct mempolicy {};
183
184static inline struct mempolicy *get_task_policy(struct task_struct *p)
185{
186 return NULL;
187}
188
189static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
190{
191 return true;
192}
193
194static inline void mpol_put(struct mempolicy *pol)
195{
196}
197
198static inline void mpol_cond_put(struct mempolicy *pol)
199{
200}
201
202static inline void mpol_get(struct mempolicy *pol)
203{
204}
205
206struct shared_policy {};
207
208static inline void mpol_shared_policy_init(struct shared_policy *sp,
209 struct mempolicy *mpol)
210{
211}
212
213static inline void mpol_free_shared_policy(struct shared_policy *sp)
214{
215}
216
217static inline struct mempolicy *
218mpol_shared_policy_lookup(struct shared_policy *sp, pgoff_t idx)
219{
220 return NULL;
221}
222
223static inline struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
224 unsigned long addr, int order, pgoff_t *ilx)
225{
226 *ilx = 0;
227 return NULL;
228}
229
230static inline int
231vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
232{
233 return 0;
234}
235
236static inline void numa_policy_init(void)
237{
238}
239
240static inline void numa_default_policy(void)
241{
242}
243
244static inline void mpol_rebind_task(struct task_struct *tsk,
245 const nodemask_t *new)
246{
247}
248
249static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
250{
251}
252
253static inline int huge_node(struct vm_area_struct *vma,
254 unsigned long addr, gfp_t gfp_flags,
255 struct mempolicy **mpol, nodemask_t **nodemask)
256{
257 *mpol = NULL;
258 *nodemask = NULL;
259 return 0;
260}
261
262static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
263{
264 return false;
265}
266
267static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
268 const nodemask_t *to, int flags)
269{
270 return 0;
271}
272
273static inline void check_highest_zone(int k)
274{
275}
276
277#ifdef CONFIG_TMPFS
278static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
279{
280 return 1; /* error */
281}
282#endif
283
284static inline int mpol_misplaced(struct folio *folio,
285 struct vm_area_struct *vma,
286 unsigned long address)
287{
288 return -1; /* no node preference */
289}
290
291static inline void mpol_put_task_policy(struct task_struct *task)
292{
293}
294
295static inline bool mpol_is_preferred_many(struct mempolicy *pol)
296{
297 return false;
298}
299
300#endif /* CONFIG_NUMA */
301#endif
302

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