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 #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
  18 struct 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  */
  46 struct 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/preferred/etc */
  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
  64 extern void __mpol_put(struct mempolicy *pol);
  65 static 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  */
  75 static inline int mpol_needs_cond_ref(struct mempolicy *pol)
  76 {
  77         return (pol && (pol->flags & MPOL_F_SHARED));
  78 }
  79
  80 static inline void mpol_cond_put(struct mempolicy *pol)
  81 {
  82         if (mpol_needs_cond_ref(pol))
  83                 __mpol_put(pol);
  84 }
  85
  86 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  87 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  88 {
  89         if (pol)
  90                 pol = __mpol_dup(pol);
  91         return pol;
  92 }
  93
  94 static inline void mpol_get(struct mempolicy *pol)
  95 {
  96         if (pol)
  97                 atomic_inc(&pol->refcnt);
  98 }
  99
 100 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 101 static 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  */
 111 struct shared_policy {
 112         struct rb_root root;
 113         rwlock_t lock;
 114 };
 115 struct sp_node {
 116         struct rb_node nd;
 117         pgoff_t start, end;
 118         struct mempolicy *policy;
 119 };
 120
 121 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
 122 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
 123 int mpol_set_shared_policy(struct shared_policy *sp,
 124                            struct vm_area_struct *vma, struct mempolicy *mpol);
 125 void mpol_free_shared_policy(struct shared_policy *sp);
 126 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 127                                             pgoff_t idx);
 128
 129 struct mempolicy *get_task_policy(struct task_struct *p);
 130 struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
 131                 unsigned long addr, pgoff_t *ilx);
 132 struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
 133                 unsigned long addr, int order, pgoff_t *ilx);
 134 bool vma_policy_mof(struct vm_area_struct *vma);
 135
 136 extern void numa_default_policy(void);
 137 extern void numa_policy_init(void);
 138 extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new);
 139 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 140
 141 extern int huge_node(struct vm_area_struct *vma,
 142                                 unsigned long addr, gfp_t gfp_flags,
 143                                 struct mempolicy **mpol, nodemask_t **nodemask);
 144 extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
 145 extern bool mempolicy_in_oom_domain(struct task_struct *tsk,
 146                                 const nodemask_t *mask);
 147 extern unsigned int mempolicy_slab_node(void);
 148
 149 extern enum zone_type policy_zone;
 150
 151 static inline void check_highest_zone(enum zone_type k)
 152 {
 153         if (k > policy_zone && k != ZONE_MOVABLE)
 154                 policy_zone = k;
 155 }
 156
 157 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 158                      const nodemask_t *to, int flags);
 159
 160
 161 #ifdef CONFIG_TMPFS
 162 extern int mpol_parse_str(char *str, struct mempolicy **mpol);
 163 #endif
 164
 165 extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
 166
 167 /* Check if a vma is migratable */
 168 extern bool vma_migratable(struct vm_area_struct *vma);
 169
 170 int mpol_misplaced(struct folio *folio, struct vm_fault *vmf,
 171                                         unsigned long addr);
 172 extern void mpol_put_task_policy(struct task_struct *);
 173
 174 static inline bool mpol_is_preferred_many(struct mempolicy *pol)
 175 {
 176         return  (pol->mode == MPOL_PREFERRED_MANY);
 177 }
 178
 179 extern bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone);
 180
 181 #else
 182
 183 struct mempolicy {};
 184
 185 static inline struct mempolicy *get_task_policy(struct task_struct *p)
 186 {
 187         return NULL;
 188 }
 189
 190 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 191 {
 192         return true;
 193 }
 194
 195 static inline void mpol_put(struct mempolicy *pol)
 196 {
 197 }
 198
 199 static inline void mpol_cond_put(struct mempolicy *pol)
 200 {
 201 }
 202
 203 static inline void mpol_get(struct mempolicy *pol)
 204 {
 205 }
 206
 207 struct shared_policy {};
 208
 209 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 210                                                 struct mempolicy *mpol)
 211 {
 212 }
 213
 214 static inline void mpol_free_shared_policy(struct shared_policy *sp)
 215 {
 216 }
 217
 218 static inline struct mempolicy *
 219 mpol_shared_policy_lookup(struct shared_policy *sp, pgoff_t idx)
 220 {
 221         return NULL;
 222 }
 223
 224 static inline struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
 225                                 unsigned long addr, int order, pgoff_t *ilx)
 226 {
 227         *ilx = 0;
 228         return NULL;
 229 }
 230
 231 static inline int
 232 vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
 233 {
 234         return 0;
 235 }
 236
 237 static inline void numa_policy_init(void)
 238 {
 239 }
 240
 241 static inline void numa_default_policy(void)
 242 {
 243 }
 244
 245 static inline void mpol_rebind_task(struct task_struct *tsk,
 246                                 const nodemask_t *new)
 247 {
 248 }
 249
 250 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 251 {
 252 }
 253
 254 static inline int huge_node(struct vm_area_struct *vma,
 255                                 unsigned long addr, gfp_t gfp_flags,
 256                                 struct mempolicy **mpol, nodemask_t **nodemask)
 257 {
 258         *mpol = NULL;
 259         *nodemask = NULL;
 260         return 0;
 261 }
 262
 263 static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
 264 {
 265         return false;
 266 }
 267
 268 static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 269                                    const nodemask_t *to, int flags)
 270 {
 271         return 0;
 272 }
 273
 274 static inline void check_highest_zone(int k)
 275 {
 276 }
 277
 278 #ifdef CONFIG_TMPFS
 279 static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
 280 {
 281         return 1;       /* error */
 282 }
 283 #endif
 284
 285 static inline int mpol_misplaced(struct folio *folio,
 286                                  struct vm_fault *vmf,
 287                                  unsigned long address)
 288 {
 289         return -1; /* no node preference */
 290 }
 291
 292 static inline void mpol_put_task_policy(struct task_struct *task)
 293 {
 294 }
 295
 296 static inline bool mpol_is_preferred_many(struct mempolicy *pol)
 297 {
 298         return  false;
 299 }
 300
 301 #endif /* CONFIG_NUMA */
 302 #endif