include/linux/mempolicy.h

   1 /*
   2  * NUMA memory policies for Linux.
   3  * Copyright 2003,2004 Andi Kleen SuSE Labs
   4  */
   5 #ifndef _LINUX_MEMPOLICY_H
   6 #define _LINUX_MEMPOLICY_H 1
   7
   8
   9 #include <linux/mmzone.h>
  10 #include <linux/slab.h>
  11 #include <linux/rbtree.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/nodemask.h>
  14 #include <linux/pagemap.h>
  15 #include <uapi/linux/mempolicy.h>
  16
  17 struct mm_struct;
  18
  19 #ifdef CONFIG_NUMA
  20
  21 /*
  22  * Describe a memory policy.
  23  *
  24  * A mempolicy can be either associated with a process or with a VMA.
  25  * For VMA related allocations the VMA policy is preferred, otherwise
  26  * the process policy is used. Interrupts ignore the memory policy
  27  * of the current process.
  28  *
  29  * Locking policy for interlave:
  30  * In process context there is no locking because only the process accesses
  31  * its own state. All vma manipulation is somewhat protected by a down_read on
  32  * mmap_sem.
  33  *
  34  * Freeing policy:
  35  * Mempolicy objects are reference counted.  A mempolicy will be freed when
  36  * mpol_put() decrements the reference count to zero.
  37  *
  38  * Duplicating policy objects:
  39  * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
  40  * to the new storage.  The reference count of the new object is initialized
  41  * to 1, representing the caller of mpol_dup().
  42  */
  43 struct mempolicy {
  44         atomic_t refcnt;
  45         unsigned short mode;    /* See MPOL_* above */
  46         unsigned short flags;   /* See set_mempolicy() MPOL_F_* above */
  47         union {
  48                 short            preferred_node; /* preferred */
  49                 nodemask_t       nodes;         /* interleave/bind */
  50                 /* undefined for default */
  51         } v;
  52         union {
  53                 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
  54                 nodemask_t user_nodemask;       /* nodemask passed by user */
  55         } w;
  56 };
  57
  58 /*
  59  * Support for managing mempolicy data objects (clone, copy, destroy)
  60  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  61  */
  62
  63 extern void __mpol_put(struct mempolicy *pol);
  64 static inline void mpol_put(struct mempolicy *pol)
  65 {
  66         if (pol)
  67                 __mpol_put(pol);
  68 }
  69
  70 /*
  71  * Does mempolicy pol need explicit unref after use?
  72  * Currently only needed for shared policies.
  73  */
  74 static inline int mpol_needs_cond_ref(struct mempolicy *pol)
  75 {
  76         return (pol && (pol->flags & MPOL_F_SHARED));
  77 }
  78
  79 static inline void mpol_cond_put(struct mempolicy *pol)
  80 {
  81         if (mpol_needs_cond_ref(pol))
  82                 __mpol_put(pol);
  83 }
  84
  85 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  86 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  87 {
  88         if (pol)
  89                 pol = __mpol_dup(pol);
  90         return pol;
  91 }
  92
  93 #define vma_policy(vma) ((vma)->vm_policy)
  94
  95 static inline void mpol_get(struct mempolicy *pol)
  96 {
  97         if (pol)
  98                 atomic_inc(&pol->refcnt);
  99 }
 100
 101 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 102 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 103 {
 104         if (a == b)
 105                 return true;
 106         return __mpol_equal(a, b);
 107 }
 108
 109 /*
 110  * Tree of shared policies for a shared memory region.
 111  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 112  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 113  * bytes, so that we can work with shared memory segments bigger than
 114  * unsigned long.
 115  */
 116
 117 struct sp_node {
 118         struct rb_node nd;
 119         unsigned long start, end;
 120         struct mempolicy *policy;
 121 };
 122
 123 struct shared_policy {
 124         struct rb_root root;
 125         spinlock_t lock;
 126 };
 127
 128 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
 129 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
 130 int mpol_set_shared_policy(struct shared_policy *info,
 131                                 struct vm_area_struct *vma,
 132                                 struct mempolicy *new);
 133 void mpol_free_shared_policy(struct shared_policy *p);
 134 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 135                                             unsigned long idx);
 136
 137 struct mempolicy *get_vma_policy(struct task_struct *tsk,
 138                 struct vm_area_struct *vma, unsigned long addr);
 139 bool vma_policy_mof(struct task_struct *task, 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                                 enum mpol_rebind_step step);
 145 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 146
 147 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 148                                 unsigned long addr, gfp_t gfp_flags,
 149                                 struct mempolicy **mpol, nodemask_t **nodemask);
 150 extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
 151 extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 152                                 const nodemask_t *mask);
 153 extern unsigned int mempolicy_slab_node(void);
 154
 155 extern enum zone_type policy_zone;
 156
 157 static inline void check_highest_zone(enum zone_type k)
 158 {
 159         if (k > policy_zone && k != ZONE_MOVABLE)
 160                 policy_zone = k;
 161 }
 162
 163 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 164                      const nodemask_t *to, int flags);
 165
 166
 167 #ifdef CONFIG_TMPFS
 168 extern int mpol_parse_str(char *str, struct mempolicy **mpol);
 169 #endif
 170
 171 extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
 172
 173 /* Check if a vma is migratable */
 174 static inline int vma_migratable(struct vm_area_struct *vma)
 175 {
 176         if (vma->vm_flags & (VM_IO | VM_PFNMAP))
 177                 return 0;
 178         /*
 179          * Migration allocates pages in the highest zone. If we cannot
 180          * do so then migration (at least from node to node) is not
 181          * possible.
 182          */
 183         if (vma->vm_file &&
 184                 gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
 185                                                                 < policy_zone)
 186                         return 0;
 187         return 1;
 188 }
 189
 190 extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
 191
 192 #else
 193
 194 struct mempolicy {};
 195
 196 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 197 {
 198         return true;
 199 }
 200
 201 static inline void mpol_put(struct mempolicy *p)
 202 {
 203 }
 204
 205 static inline void mpol_cond_put(struct mempolicy *pol)
 206 {
 207 }
 208
 209 static inline void mpol_get(struct mempolicy *pol)
 210 {
 211 }
 212
 213 struct shared_policy {};
 214
 215 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 216                                                 struct mempolicy *mpol)
 217 {
 218 }
 219
 220 static inline void mpol_free_shared_policy(struct shared_policy *p)
 221 {
 222 }
 223
 224 #define vma_policy(vma) NULL
 225
 226 static inline int
 227 vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
 228 {
 229         return 0;
 230 }
 231
 232 static inline void numa_policy_init(void)
 233 {
 234 }
 235
 236 static inline void numa_default_policy(void)
 237 {
 238 }
 239
 240 static inline void mpol_rebind_task(struct task_struct *tsk,
 241                                 const nodemask_t *new,
 242                                 enum mpol_rebind_step step)
 243 {
 244 }
 245
 246 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 247 {
 248 }
 249
 250 static inline struct zonelist *huge_zonelist(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 node_zonelist(0, gfp_flags);
 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 #endif /* CONFIG_NUMA */
 288 #endif