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 /*
  12  * Both the MPOL_* mempolicy mode and the MPOL_F_* optional mode flags are
  13  * passed by the user to either set_mempolicy() or mbind() in an 'int' actual.
  14  * The MPOL_MODE_FLAGS macro determines the legal set of optional mode flags.
  15  */
  16
  17 /* Policies */
  18 enum {
  19         MPOL_DEFAULT,
  20         MPOL_PREFERRED,
  21         MPOL_BIND,
  22         MPOL_INTERLEAVE,
  23         MPOL_MAX,       /* always last member of enum */
  24 };
  25
  26 /* Flags for set_mempolicy */
  27 #define MPOL_F_STATIC_NODES     (1 << 15)
  28 #define MPOL_F_RELATIVE_NODES   (1 << 14)
  29
  30 /*
  31  * MPOL_MODE_FLAGS is the union of all possible optional mode flags passed to
  32  * either set_mempolicy() or mbind().
  33  */
  34 #define MPOL_MODE_FLAGS (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES)
  35
  36 /* Flags for get_mempolicy */
  37 #define MPOL_F_NODE     (1<<0)  /* return next IL mode instead of node mask */
  38 #define MPOL_F_ADDR     (1<<1)  /* look up vma using address */
  39 #define MPOL_F_MEMS_ALLOWED (1<<2) /* return allowed memories */
  40
  41 /* Flags for mbind */
  42 #define MPOL_MF_STRICT  (1<<0)  /* Verify existing pages in the mapping */
  43 #define MPOL_MF_MOVE    (1<<1)  /* Move pages owned by this process to conform to mapping */
  44 #define MPOL_MF_MOVE_ALL (1<<2) /* Move every page to conform to mapping */
  45 #define MPOL_MF_INTERNAL (1<<3) /* Internal flags start here */
  46
  47 /*
  48  * Internal flags that share the struct mempolicy flags word with
  49  * "mode flags".  These flags are allocated from bit 0 up, as they
  50  * are never OR'ed into the mode in mempolicy API arguments.
  51  */
  52 #define MPOL_F_SHARED  (1 << 0) /* identify shared policies */
  53
  54 #ifdef __KERNEL__
  55
  56 #include <linux/mmzone.h>
  57 #include <linux/slab.h>
  58 #include <linux/rbtree.h>
  59 #include <linux/spinlock.h>
  60 #include <linux/nodemask.h>
  61
  62 struct mm_struct;
  63
  64 #ifdef CONFIG_NUMA
  65
  66 /*
  67  * Describe a memory policy.
  68  *
  69  * A mempolicy can be either associated with a process or with a VMA.
  70  * For VMA related allocations the VMA policy is preferred, otherwise
  71  * the process policy is used. Interrupts ignore the memory policy
  72  * of the current process.
  73  *
  74  * Locking policy for interlave:
  75  * In process context there is no locking because only the process accesses
  76  * its own state. All vma manipulation is somewhat protected by a down_read on
  77  * mmap_sem.
  78  *
  79  * Freeing policy:
  80  * Mempolicy objects are reference counted.  A mempolicy will be freed when
  81  * mpol_put() decrements the reference count to zero.
  82  *
  83  * Duplicating policy objects:
  84  * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
  85  * to the new storage.  The reference count of the new object is initialized
  86  * to 1, representing the caller of mpol_dup().
  87  */
  88 struct mempolicy {
  89         atomic_t refcnt;
  90         unsigned short mode;    /* See MPOL_* above */
  91         unsigned short flags;   /* See set_mempolicy() MPOL_F_* above */
  92         union {
  93                 short            preferred_node; /* preferred */
  94                 nodemask_t       nodes;         /* interleave/bind */
  95                 /* undefined for default */
  96         } v;
  97         union {
  98                 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
  99                 nodemask_t user_nodemask;       /* nodemask passed by user */
 100         } w;
 101 };
 102
 103 /*
 104  * Support for managing mempolicy data objects (clone, copy, destroy)
 105  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
 106  */
 107
 108 extern void __mpol_put(struct mempolicy *pol);
 109 static inline void mpol_put(struct mempolicy *pol)
 110 {
 111         if (pol)
 112                 __mpol_put(pol);
 113 }
 114
 115 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
 116 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
 117 {
 118         if (pol)
 119                 pol = __mpol_dup(pol);
 120         return pol;
 121 }
 122
 123 #define vma_policy(vma) ((vma)->vm_policy)
 124 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
 125
 126 static inline void mpol_get(struct mempolicy *pol)
 127 {
 128         if (pol)
 129                 atomic_inc(&pol->refcnt);
 130 }
 131
 132 extern int __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 133 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 134 {
 135         if (a == b)
 136                 return 1;
 137         return __mpol_equal(a, b);
 138 }
 139
 140 /*
 141  * Tree of shared policies for a shared memory region.
 142  * Maintain the policies in a pseudo mm that contains vmas. The vmas
 143  * carry the policy. As a special twist the pseudo mm is indexed in pages, not
 144  * bytes, so that we can work with shared memory segments bigger than
 145  * unsigned long.
 146  */
 147
 148 struct sp_node {
 149         struct rb_node nd;
 150         unsigned long start, end;
 151         struct mempolicy *policy;
 152 };
 153
 154 struct shared_policy {
 155         struct rb_root root;
 156         spinlock_t lock;
 157 };
 158
 159 void mpol_shared_policy_init(struct shared_policy *info, unsigned short mode,
 160                                 unsigned short flags, nodemask_t *nodes);
 161 int mpol_set_shared_policy(struct shared_policy *info,
 162                                 struct vm_area_struct *vma,
 163                                 struct mempolicy *new);
 164 void mpol_free_shared_policy(struct shared_policy *p);
 165 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 166                                             unsigned long idx);
 167
 168 extern void numa_default_policy(void);
 169 extern void numa_policy_init(void);
 170 extern void mpol_rebind_task(struct task_struct *tsk,
 171                                         const nodemask_t *new);
 172 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 173 extern void mpol_fix_fork_child_flag(struct task_struct *p);
 174
 175 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 176                                 unsigned long addr, gfp_t gfp_flags,
 177                                 struct mempolicy **mpol, nodemask_t **nodemask);
 178 extern unsigned slab_node(struct mempolicy *policy);
 179
 180 extern enum zone_type policy_zone;
 181
 182 static inline void check_highest_zone(enum zone_type k)
 183 {
 184         if (k > policy_zone && k != ZONE_MOVABLE)
 185                 policy_zone = k;
 186 }
 187
 188 int do_migrate_pages(struct mm_struct *mm,
 189         const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags);
 190
 191 #else
 192
 193 struct mempolicy {};
 194
 195 static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
 196 {
 197         return 1;
 198 }
 199
 200 static inline void mpol_put(struct mempolicy *p)
 201 {
 202 }
 203
 204 static inline void mpol_get(struct mempolicy *pol)
 205 {
 206 }
 207
 208 static inline struct mempolicy *mpol_dup(struct mempolicy *old)
 209 {
 210         return NULL;
 211 }
 212
 213 struct shared_policy {};
 214
 215 static inline int mpol_set_shared_policy(struct shared_policy *info,
 216                                         struct vm_area_struct *vma,
 217                                         struct mempolicy *new)
 218 {
 219         return -EINVAL;
 220 }
 221
 222 static inline void mpol_shared_policy_init(struct shared_policy *info,
 223                 unsigned short mode, unsigned short flags, nodemask_t *nodes)
 224 {
 225 }
 226
 227 static inline void mpol_free_shared_policy(struct shared_policy *p)
 228 {
 229 }
 230
 231 static inline struct mempolicy *
 232 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 233 {
 234         return NULL;
 235 }
 236
 237 #define vma_policy(vma) NULL
 238 #define vma_set_policy(vma, pol) do {} while(0)
 239
 240 static inline void numa_policy_init(void)
 241 {
 242 }
 243
 244 static inline void numa_default_policy(void)
 245 {
 246 }
 247
 248 static inline void mpol_rebind_task(struct task_struct *tsk,
 249                                         const nodemask_t *new)
 250 {
 251 }
 252
 253 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 254 {
 255 }
 256
 257 static inline void mpol_fix_fork_child_flag(struct task_struct *p)
 258 {
 259 }
 260
 261 static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 262                                 unsigned long addr, gfp_t gfp_flags,
 263                                 struct mempolicy **mpol, nodemask_t **nodemask)
 264 {
 265         *mpol = NULL;
 266         *nodemask = NULL;
 267         return node_zonelist(0, gfp_flags);
 268 }
 269
 270 static inline int do_migrate_pages(struct mm_struct *mm,
 271                         const nodemask_t *from_nodes,
 272                         const nodemask_t *to_nodes, int flags)
 273 {
 274         return 0;
 275 }
 276
 277 static inline void check_highest_zone(int k)
 278 {
 279 }
 280 #endif /* CONFIG_NUMA */
 281 #endif /* __KERNEL__ */
 282
 283 #endif