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/bitmap.h>
  31 #include <linux/slab.h>
  32 #include <linux/rbtree.h>
  33 #include <linux/spinlock.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. For allocating in the interleave policy the page_table_lock
  51  * must be also aquired to protect il_next.
  52  *
  53  * Freeing policy:
  54  * When policy is MPOL_BIND v.zonelist is kmalloc'ed and must be kfree'd.
  55  * All other policies don't have any external state. mpol_free() handles this.
  56  *
  57  * Copying policy objects:
  58  * For MPOL_BIND the zonelist must be always duplicated. mpol_clone() does this.
  59  */
  60 struct mempolicy {
  61         atomic_t refcnt;
  62         short policy;   /* See MPOL_* above */
  63         union {
  64                 struct zonelist  *zonelist;     /* bind */
  65                 short            preferred_node; /* preferred */
  66                 DECLARE_BITMAP(nodes, MAX_NUMNODES); /* interleave */
  67                 /* undefined for default */
  68         } v;
  69 };
  70
  71 /*
  72  * Support for managing mempolicy data objects (clone, copy, destroy)
  73  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  74  */
  75
  76 extern void __mpol_free(struct mempolicy *pol);
  77 static inline void mpol_free(struct mempolicy *pol)
  78 {
  79         if (pol)
  80                 __mpol_free(pol);
  81 }
  82
  83 extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
  84 static inline struct mempolicy *mpol_copy(struct mempolicy *pol)
  85 {
  86         if (pol)
  87                 pol = __mpol_copy(pol);
  88         return pol;
  89 }
  90
  91 #define vma_policy(vma) ((vma)->vm_policy)
  92 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
  93
  94 static inline void mpol_get(struct mempolicy *pol)
  95 {
  96         if (pol)
  97                 atomic_inc(&pol->refcnt);
  98 }
  99
 100 extern int __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 101 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 102 {
 103         if (a == b)
 104                 return 1;
 105         return __mpol_equal(a, b);
 106 }
 107 #define vma_mpol_equal(a,b) mpol_equal(vma_policy(a), vma_policy(b))
 108
 109 /* Could later add inheritance of the process policy here. */
 110
 111 #define mpol_set_vma_default(vma) ((vma)->vm_policy = NULL)
 112
 113 /*
 114  * Hugetlb policy. i386 hugetlb so far works with node numbers
 115  * instead of zone lists, so give it special interfaces for now.
 116  */
 117 extern int mpol_first_node(struct vm_area_struct *vma, unsigned long addr);
 118 extern int mpol_node_valid(int nid, struct vm_area_struct *vma,
 119                         unsigned long addr);
 120
 121 /*
 122  * Tree of shared policies for a shared memory region.
 123  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 124  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 125  * bytes, so that we can work with shared memory segments bigger than
 126  * unsigned long.
 127  */
 128
 129 struct sp_node {
 130         struct rb_node nd;
 131         unsigned long start, end;
 132         struct mempolicy *policy;
 133 };
 134
 135 struct shared_policy {
 136         struct rb_root root;
 137         spinlock_t lock;
 138 };
 139
 140 static inline void mpol_shared_policy_init(struct shared_policy *info)
 141 {
 142         info->root = RB_ROOT;
 143         spin_lock_init(&info->lock);
 144 }
 145
 146 int mpol_set_shared_policy(struct shared_policy *info,
 147                                 struct vm_area_struct *vma,
 148                                 struct mempolicy *new);
 149 void mpol_free_shared_policy(struct shared_policy *p);
 150 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 151                                             unsigned long idx);
 152
 153 struct mempolicy *get_vma_policy(struct task_struct *task,
 154                         struct vm_area_struct *vma, unsigned long addr);
 155
 156 extern void numa_default_policy(void);
 157 extern void numa_policy_init(void);
 158
 159 #else
 160
 161 struct mempolicy {};
 162
 163 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 164 {
 165         return 1;
 166 }
 167 #define vma_mpol_equal(a,b) 1
 168
 169 #define mpol_set_vma_default(vma) do {} while(0)
 170
 171 static inline void mpol_free(struct mempolicy *p)
 172 {
 173 }
 174
 175 static inline void mpol_get(struct mempolicy *pol)
 176 {
 177 }
 178
 179 static inline struct mempolicy *mpol_copy(struct mempolicy *old)
 180 {
 181         return NULL;
 182 }
 183
 184 static inline int mpol_first_node(struct vm_area_struct *vma, unsigned long a)
 185 {
 186         return numa_node_id();
 187 }
 188
 189 static inline int
 190 mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long a)
 191 {
 192         return 1;
 193 }
 194
 195 struct shared_policy {};
 196
 197 static inline int mpol_set_shared_policy(struct shared_policy *info,
 198                                         struct vm_area_struct *vma,
 199                                         struct mempolicy *new)
 200 {
 201         return -EINVAL;
 202 }
 203
 204 static inline void mpol_shared_policy_init(struct shared_policy *info)
 205 {
 206 }
 207
 208 static inline void mpol_free_shared_policy(struct shared_policy *p)
 209 {
 210 }
 211
 212 static inline struct mempolicy *
 213 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 214 {
 215         return NULL;
 216 }
 217
 218 #define vma_policy(vma) NULL
 219 #define vma_set_policy(vma, pol) do {} while(0)
 220
 221 static inline void numa_policy_init(void)
 222 {
 223 }
 224
 225 static inline void numa_default_policy(void)
 226 {
 227 }
 228
 229 #endif /* CONFIG_NUMA */
 230 #endif /* __KERNEL__ */
 231
 232 #endif