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/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 interleave:
  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_lock.
  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         nodemask_t nodes;       /* interleave/bind/perfer */
  50
  51         union {
  52                 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
  53                 nodemask_t user_nodemask;       /* nodemask passed by user */
  54         } w;
  55 };
  56
  57 /*
  58  * Support for managing mempolicy data objects (clone, copy, destroy)
  59  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  60  */
  61
  62 extern void __mpol_put(struct mempolicy *pol);
  63 static inline void mpol_put(struct mempolicy *pol)
  64 {
  65         if (pol)
  66                 __mpol_put(pol);
  67 }
  68
  69 /*
  70  * Does mempolicy pol need explicit unref after use?
  71  * Currently only needed for shared policies.
  72  */
  73 static inline int mpol_needs_cond_ref(struct mempolicy *pol)
  74 {
  75         return (pol && (pol->flags & MPOL_F_SHARED));
  76 }
  77
  78 static inline void mpol_cond_put(struct mempolicy *pol)
  79 {
  80         if (mpol_needs_cond_ref(pol))
  81                 __mpol_put(pol);
  82 }
  83
  84 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  85 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  86 {
  87         if (pol)
  88                 pol = __mpol_dup(pol);
  89         return pol;
  90 }
  91
  92 #define vma_policy(vma) ((vma)->vm_policy)
  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  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 111  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 112  * bytes, so that we can work with shared memory segments bigger than
 113  * unsigned long.
 114  */
 115
 116 struct sp_node {
 117         struct rb_node nd;
 118         unsigned long start, end;
 119         struct mempolicy *policy;
 120 };
 121
 122 struct shared_policy {
 123         struct rb_root root;
 124         rwlock_t lock;
 125 };
 126
 127 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
 128 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
 129 int mpol_set_shared_policy(struct shared_policy *info,
 130                                 struct vm_area_struct *vma,
 131                                 struct mempolicy *new);
 132 void mpol_free_shared_policy(struct shared_policy *p);
 133 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 134                                             unsigned long idx);
 135
 136 struct mempolicy *get_task_policy(struct task_struct *p);
 137 struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
 138                 unsigned long addr);
 139 bool vma_policy_mof(struct vm_area_struct *vma);
 140
 141 extern void numa_default_policy(void);
 142 extern void numa_policy_init(void);
 143 extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new);
 144 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 145
 146 extern int huge_node(struct vm_area_struct *vma,
 147                                 unsigned long addr, gfp_t gfp_flags,
 148                                 struct mempolicy **mpol, nodemask_t **nodemask);
 149 extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
 150 extern bool mempolicy_in_oom_domain(struct task_struct *tsk,
 151                                 const nodemask_t *mask);
 152 extern nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy);
 153
 154 static inline nodemask_t *policy_nodemask_current(gfp_t gfp)
 155 {
 156         struct mempolicy *mpol = get_task_policy(current);
 157
 158         return policy_nodemask(gfp, mpol);
 159 }
 160
 161 extern unsigned int mempolicy_slab_node(void);
 162
 163 extern enum zone_type policy_zone;
 164
 165 static inline void check_highest_zone(enum zone_type k)
 166 {
 167         if (k > policy_zone && k != ZONE_MOVABLE)
 168                 policy_zone = k;
 169 }
 170
 171 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 172                      const nodemask_t *to, int flags);
 173
 174
 175 #ifdef CONFIG_TMPFS
 176 extern int mpol_parse_str(char *str, struct mempolicy **mpol);
 177 #endif
 178
 179 extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
 180
 181 /* Check if a vma is migratable */
 182 extern bool vma_migratable(struct vm_area_struct *vma);
 183
 184 extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
 185 extern void mpol_put_task_policy(struct task_struct *);
 186
 187 #else
 188
 189 struct mempolicy {};
 190
 191 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 192 {
 193         return true;
 194 }
 195
 196 static inline void mpol_put(struct mempolicy *p)
 197 {
 198 }
 199
 200 static inline void mpol_cond_put(struct mempolicy *pol)
 201 {
 202 }
 203
 204 static inline void mpol_get(struct mempolicy *pol)
 205 {
 206 }
 207
 208 struct shared_policy {};
 209
 210 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 211                                                 struct mempolicy *mpol)
 212 {
 213 }
 214
 215 static inline void mpol_free_shared_policy(struct shared_policy *p)
 216 {
 217 }
 218
 219 static inline struct mempolicy *
 220 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 221 {
 222         return NULL;
 223 }
 224
 225 #define vma_policy(vma) NULL
 226
 227 static inline int
 228 vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
 229 {
 230         return 0;
 231 }
 232
 233 static inline void numa_policy_init(void)
 234 {
 235 }
 236
 237 static inline void numa_default_policy(void)
 238 {
 239 }
 240
 241 static inline void mpol_rebind_task(struct task_struct *tsk,
 242                                 const nodemask_t *new)
 243 {
 244 }
 245
 246 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 247 {
 248 }
 249
 250 static inline int huge_node(struct vm_area_struct *vma,
 251                                 unsigned long addr, gfp_t gfp_flags,
 252                                 struct mempolicy **mpol, nodemask_t **nodemask)
 253 {
 254         *mpol = NULL;
 255         *nodemask = NULL;
 256         return 0;
 257 }
 258
 259 static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
 260 {
 261         return false;
 262 }
 263
 264 static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 265                                    const nodemask_t *to, int flags)
 266 {
 267         return 0;
 268 }
 269
 270 static inline void check_highest_zone(int k)
 271 {
 272 }
 273
 274 #ifdef CONFIG_TMPFS
 275 static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
 276 {
 277         return 1;       /* error */
 278 }
 279 #endif
 280
 281 static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
 282                                  unsigned long address)
 283 {
 284         return -1; /* no node preference */
 285 }
 286
 287 static inline void mpol_put_task_policy(struct task_struct *task)
 288 {
 289 }
 290
 291 static inline nodemask_t *policy_nodemask_current(gfp_t gfp)
 292 {
 293         return NULL;
 294 }
 295 #endif /* CONFIG_NUMA */
 296 #endif