include/linux/mempolicy.h

   1 #ifndef _LINUX_MEMPOLICY_H
   2 #define _LINUX_MEMPOLICY_H 1
   3
   4 #include <linux/errno.h>
   5
   6 /*
   7  * NUMA memory policies for Linux.
   8  * Copyright 2003,2004 Andi Kleen SuSE Labs
   9  */
  10
  11 /* Policies */
  12 #define MPOL_DEFAULT    0
  13 #define MPOL_PREFERRED  1
  14 #define MPOL_BIND       2
  15 #define MPOL_INTERLEAVE 3
  16
  17 #define MPOL_MAX MPOL_INTERLEAVE
  18
  19 /* Flags for get_mem_policy */
  20 #define MPOL_F_NODE     (1<<0)  /* return next IL mode instead of node mask */
  21 #define MPOL_F_ADDR     (1<<1)  /* look up vma using address */
  22
  23 /* Flags for mbind */
  24 #define MPOL_MF_STRICT  (1<<0)  /* Verify existing pages in the mapping */
  25
  26 #ifdef __KERNEL__
  27
  28 #include <linux/config.h>
  29 #include <linux/mmzone.h>
  30 #include <linux/slab.h>
  31 #include <linux/rbtree.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/nodemask.h>
  34
  35 struct vm_area_struct;
  36
  37 #ifdef CONFIG_NUMA
  38
  39 /*
  40  * Describe a memory policy.
  41  *
  42  * A mempolicy can be either associated with a process or with a VMA.
  43  * For VMA related allocations the VMA policy is preferred, otherwise
  44  * the process policy is used. Interrupts ignore the memory policy
  45  * of the current process.
  46  *
  47  * Locking policy for interlave:
  48  * In process context there is no locking because only the process accesses
  49  * its own state. All vma manipulation is somewhat protected by a down_read on
  50  * mmap_sem.
  51  *
  52  * Freeing policy:
  53  * When policy is MPOL_BIND v.zonelist is kmalloc'ed and must be kfree'd.
  54  * All other policies don't have any external state. mpol_free() handles this.
  55  *
  56  * Copying policy objects:
  57  * For MPOL_BIND the zonelist must be always duplicated. mpol_clone() does this.
  58  */
  59 struct mempolicy {
  60         atomic_t refcnt;
  61         short policy;   /* See MPOL_* above */
  62         union {
  63                 struct zonelist  *zonelist;     /* bind */
  64                 short            preferred_node; /* preferred */
  65                 nodemask_t       nodes;         /* interleave */
  66                 /* undefined for default */
  67         } v;
  68 };
  69
  70 /*
  71  * Support for managing mempolicy data objects (clone, copy, destroy)
  72  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  73  */
  74
  75 extern void __mpol_free(struct mempolicy *pol);
  76 static inline void mpol_free(struct mempolicy *pol)
  77 {
  78         if (pol)
  79                 __mpol_free(pol);
  80 }
  81
  82 extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
  83 static inline struct mempolicy *mpol_copy(struct mempolicy *pol)
  84 {
  85         if (pol)
  86                 pol = __mpol_copy(pol);
  87         return pol;
  88 }
  89
  90 #define vma_policy(vma) ((vma)->vm_policy)
  91 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
  92
  93 static inline void mpol_get(struct mempolicy *pol)
  94 {
  95         if (pol)
  96                 atomic_inc(&pol->refcnt);
  97 }
  98
  99 extern int __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 100 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 101 {
 102         if (a == b)
 103                 return 1;
 104         return __mpol_equal(a, b);
 105 }
 106 #define vma_mpol_equal(a,b) mpol_equal(vma_policy(a), vma_policy(b))
 107
 108 /* Could later add inheritance of the process policy here. */
 109
 110 #define mpol_set_vma_default(vma) ((vma)->vm_policy = NULL)
 111
 112 /*
 113  * Hugetlb policy. i386 hugetlb so far works with node numbers
 114  * instead of zone lists, so give it special interfaces for now.
 115  */
 116 extern int mpol_first_node(struct vm_area_struct *vma, unsigned long addr);
 117 extern int mpol_node_valid(int nid, struct vm_area_struct *vma,
 118                         unsigned long addr);
 119
 120 /*
 121  * Tree of shared policies for a shared memory region.
 122  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 123  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 124  * bytes, so that we can work with shared memory segments bigger than
 125  * unsigned long.
 126  */
 127
 128 struct sp_node {
 129         struct rb_node nd;
 130         unsigned long start, end;
 131         struct mempolicy *policy;
 132 };
 133
 134 struct shared_policy {
 135         struct rb_root root;
 136         spinlock_t lock;
 137 };
 138
 139 static inline void mpol_shared_policy_init(struct shared_policy *info)
 140 {
 141         info->root = RB_ROOT;
 142         spin_lock_init(&info->lock);
 143 }
 144
 145 int mpol_set_shared_policy(struct shared_policy *info,
 146                                 struct vm_area_struct *vma,
 147                                 struct mempolicy *new);
 148 void mpol_free_shared_policy(struct shared_policy *p);
 149 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 150                                             unsigned long idx);
 151
 152 struct mempolicy *get_vma_policy(struct task_struct *task,
 153                         struct vm_area_struct *vma, unsigned long addr);
 154
 155 extern void numa_default_policy(void);
 156 extern void numa_policy_init(void);
 157 extern void numa_policy_rebind(const nodemask_t *old, const nodemask_t *new);
 158 extern struct mempolicy default_policy;
 159
 160 #else
 161
 162 struct mempolicy {};
 163
 164 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 165 {
 166         return 1;
 167 }
 168 #define vma_mpol_equal(a,b) 1
 169
 170 #define mpol_set_vma_default(vma) do {} while(0)
 171
 172 static inline void mpol_free(struct mempolicy *p)
 173 {
 174 }
 175
 176 static inline void mpol_get(struct mempolicy *pol)
 177 {
 178 }
 179
 180 static inline struct mempolicy *mpol_copy(struct mempolicy *old)
 181 {
 182         return NULL;
 183 }
 184
 185 static inline int mpol_first_node(struct vm_area_struct *vma, unsigned long a)
 186 {
 187         return numa_node_id();
 188 }
 189
 190 static inline int
 191 mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long a)
 192 {
 193         return 1;
 194 }
 195
 196 struct shared_policy {};
 197
 198 static inline int mpol_set_shared_policy(struct shared_policy *info,
 199                                         struct vm_area_struct *vma,
 200                                         struct mempolicy *new)
 201 {
 202         return -EINVAL;
 203 }
 204
 205 static inline void mpol_shared_policy_init(struct shared_policy *info)
 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 #define vma_set_policy(vma, pol) do {} while(0)
 221
 222 static inline void numa_policy_init(void)
 223 {
 224 }
 225
 226 static inline void numa_default_policy(void)
 227 {
 228 }
 229
 230 static inline void numa_policy_rebind(const nodemask_t *old,
 231                                         const nodemask_t *new)
 232 {
 233 }
 234
 235 #endif /* CONFIG_NUMA */
 236 #endif /* __KERNEL__ */
 237
 238 #endif