include/linux/mempolicy.h

   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
  10 #include <linux/mmzone.h>
  11 #include <linux/dax.h>
  12 #include <linux/slab.h>
  13 #include <linux/rbtree.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/nodemask.h>
  16 #include <linux/pagemap.h>
  17 #include <uapi/linux/mempolicy.h>
  18
  19 struct mm_struct;
  20
  21 #ifdef CONFIG_NUMA
  22
  23 /*
  24  * Describe a memory policy.
  25  *
  26  * A mempolicy can be either associated with a process or with a VMA.
  27  * For VMA related allocations the VMA policy is preferred, otherwise
  28  * the process policy is used. Interrupts ignore the memory policy
  29  * of the current process.
  30  *
  31  * Locking policy for interlave:
  32  * In process context there is no locking because only the process accesses
  33  * its own state. All vma manipulation is somewhat protected by a down_read on
  34  * mmap_sem.
  35  *
  36  * Freeing policy:
  37  * Mempolicy objects are reference counted.  A mempolicy will be freed when
  38  * mpol_put() decrements the reference count to zero.
  39  *
  40  * Duplicating policy objects:
  41  * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
  42  * to the new storage.  The reference count of the new object is initialized
  43  * to 1, representing the caller of mpol_dup().
  44  */
  45 struct mempolicy {
  46         atomic_t refcnt;
  47         unsigned short mode;    /* See MPOL_* above */
  48         unsigned short flags;   /* See set_mempolicy() MPOL_F_* above */
  49         union {
  50                 short            preferred_node; /* preferred */
  51                 nodemask_t       nodes;         /* interleave/bind */
  52                 /* undefined for default */
  53         } v;
  54         union {
  55                 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
  56                 nodemask_t user_nodemask;       /* nodemask passed by user */
  57         } w;
  58 };
  59
  60 /*
  61  * Support for managing mempolicy data objects (clone, copy, destroy)
  62  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  63  */
  64
  65 extern void __mpol_put(struct mempolicy *pol);
  66 static inline void mpol_put(struct mempolicy *pol)
  67 {
  68         if (pol)
  69                 __mpol_put(pol);
  70 }
  71
  72 /*
  73  * Does mempolicy pol need explicit unref after use?
  74  * Currently only needed for shared policies.
  75  */
  76 static inline int mpol_needs_cond_ref(struct mempolicy *pol)
  77 {
  78         return (pol && (pol->flags & MPOL_F_SHARED));
  79 }
  80
  81 static inline void mpol_cond_put(struct mempolicy *pol)
  82 {
  83         if (mpol_needs_cond_ref(pol))
  84                 __mpol_put(pol);
  85 }
  86
  87 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  88 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  89 {
  90         if (pol)
  91                 pol = __mpol_dup(pol);
  92         return pol;
  93 }
  94
  95 #define vma_policy(vma) ((vma)->vm_policy)
  96
  97 static inline void mpol_get(struct mempolicy *pol)
  98 {
  99         if (pol)
 100                 atomic_inc(&pol->refcnt);
 101 }
 102
 103 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 104 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 105 {
 106         if (a == b)
 107                 return true;
 108         return __mpol_equal(a, b);
 109 }
 110
 111 /*
 112  * Tree of shared policies for a shared memory region.
 113  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 114  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 115  * bytes, so that we can work with shared memory segments bigger than
 116  * unsigned long.
 117  */
 118
 119 struct sp_node {
 120         struct rb_node nd;
 121         unsigned long start, end;
 122         struct mempolicy *policy;
 123 };
 124
 125 struct shared_policy {
 126         struct rb_root root;
 127         rwlock_t lock;
 128 };
 129
 130 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
 131 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
 132 int mpol_set_shared_policy(struct shared_policy *info,
 133                                 struct vm_area_struct *vma,
 134                                 struct mempolicy *new);
 135 void mpol_free_shared_policy(struct shared_policy *p);
 136 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 137                                             unsigned long idx);
 138
 139 struct mempolicy *get_task_policy(struct task_struct *p);
 140 struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
 141                 unsigned long addr);
 142 bool vma_policy_mof(struct vm_area_struct *vma);
 143
 144 extern void numa_default_policy(void);
 145 extern void numa_policy_init(void);
 146 extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new);
 147 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 148
 149 extern int huge_node(struct vm_area_struct *vma,
 150                                 unsigned long addr, gfp_t gfp_flags,
 151                                 struct mempolicy **mpol, nodemask_t **nodemask);
 152 extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
 153 extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 154                                 const nodemask_t *mask);
 155 extern unsigned int mempolicy_slab_node(void);
 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, const nodemask_t *from,
 166                      const nodemask_t *to, int flags);
 167
 168
 169 #ifdef CONFIG_TMPFS
 170 extern int mpol_parse_str(char *str, struct mempolicy **mpol);
 171 #endif
 172
 173 extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
 174
 175 /* Check if a vma is migratable */
 176 extern bool vma_migratable(struct vm_area_struct *vma);
 177
 178 extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
 179 extern void mpol_put_task_policy(struct task_struct *);
 180
 181 #else
 182
 183 struct mempolicy {};
 184
 185 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 186 {
 187         return true;
 188 }
 189
 190 static inline void mpol_put(struct mempolicy *p)
 191 {
 192 }
 193
 194 static inline void mpol_cond_put(struct mempolicy *pol)
 195 {
 196 }
 197
 198 static inline void mpol_get(struct mempolicy *pol)
 199 {
 200 }
 201
 202 struct shared_policy {};
 203
 204 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 205                                                 struct mempolicy *mpol)
 206 {
 207 }
 208
 209 static inline void mpol_free_shared_policy(struct shared_policy *p)
 210 {
 211 }
 212
 213 static inline struct mempolicy *
 214 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 215 {
 216         return NULL;
 217 }
 218
 219 #define vma_policy(vma) NULL
 220
 221 static inline int
 222 vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
 223 {
 224         return 0;
 225 }
 226
 227 static inline void numa_policy_init(void)
 228 {
 229 }
 230
 231 static inline void numa_default_policy(void)
 232 {
 233 }
 234
 235 static inline void mpol_rebind_task(struct task_struct *tsk,
 236                                 const nodemask_t *new)
 237 {
 238 }
 239
 240 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 241 {
 242 }
 243
 244 static inline int huge_node(struct vm_area_struct *vma,
 245                                 unsigned long addr, gfp_t gfp_flags,
 246                                 struct mempolicy **mpol, nodemask_t **nodemask)
 247 {
 248         *mpol = NULL;
 249         *nodemask = NULL;
 250         return 0;
 251 }
 252
 253 static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
 254 {
 255         return false;
 256 }
 257
 258 static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 259                                    const nodemask_t *to, int flags)
 260 {
 261         return 0;
 262 }
 263
 264 static inline void check_highest_zone(int k)
 265 {
 266 }
 267
 268 #ifdef CONFIG_TMPFS
 269 static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
 270 {
 271         return 1;       /* error */
 272 }
 273 #endif
 274
 275 static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
 276                                  unsigned long address)
 277 {
 278         return -1; /* no node preference */
 279 }
 280
 281 static inline void mpol_put_task_policy(struct task_struct *task)
 282 {
 283 }
 284 #endif /* CONFIG_NUMA */
 285 #endif