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_cond_copy(struct mempolicy *tompol,
  86                                           struct mempolicy *frompol);
  87 static inline struct mempolicy *mpol_cond_copy(struct mempolicy *tompol,
  88                                                 struct mempolicy *frompol)
  89 {
  90         if (!frompol)
  91                 return frompol;
  92         return __mpol_cond_copy(tompol, frompol);
  93 }
  94
  95 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  96 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  97 {
  98         if (pol)
  99                 pol = __mpol_dup(pol);
 100         return pol;
 101 }
 102
 103 #define vma_policy(vma) ((vma)->vm_policy)
 104 #define vma_set_policy(vma, pol) ((vma)->vm_policy = (pol))
 105
 106 static inline void mpol_get(struct mempolicy *pol)
 107 {
 108         if (pol)
 109                 atomic_inc(&pol->refcnt);
 110 }
 111
 112 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
 113 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 114 {
 115         if (a == b)
 116                 return true;
 117         return __mpol_equal(a, b);
 118 }
 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         struct mutex mutex;
 137 };
 138
 139 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
 140 int mpol_set_shared_policy(struct shared_policy *info,
 141                                 struct vm_area_struct *vma,
 142                                 struct mempolicy *new);
 143 void mpol_free_shared_policy(struct shared_policy *p);
 144 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
 145                                             unsigned long idx);
 146
 147 struct mempolicy *get_vma_policy(struct task_struct *tsk,
 148                 struct vm_area_struct *vma, unsigned long addr);
 149
 150 extern void numa_default_policy(void);
 151 extern void numa_policy_init(void);
 152 extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
 153                                 enum mpol_rebind_step step);
 154 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 155 extern void mpol_fix_fork_child_flag(struct task_struct *p);
 156
 157 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 158                                 unsigned long addr, gfp_t gfp_flags,
 159                                 struct mempolicy **mpol, nodemask_t **nodemask);
 160 extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
 161 extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 162                                 const nodemask_t *mask);
 163 extern unsigned slab_node(void);
 164
 165 extern enum zone_type policy_zone;
 166
 167 static inline void check_highest_zone(enum zone_type k)
 168 {
 169         if (k > policy_zone && k != ZONE_MOVABLE)
 170                 policy_zone = k;
 171 }
 172
 173 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 174                      const nodemask_t *to, int flags);
 175
 176
 177 #ifdef CONFIG_TMPFS
 178 extern int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context);
 179 #endif
 180
 181 extern int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol,
 182                         int no_context);
 183
 184 /* Check if a vma is migratable */
 185 static inline int vma_migratable(struct vm_area_struct *vma)
 186 {
 187         if (vma->vm_flags & (VM_IO | VM_HUGETLB | VM_PFNMAP))
 188                 return 0;
 189         /*
 190          * Migration allocates pages in the highest zone. If we cannot
 191          * do so then migration (at least from node to node) is not
 192          * possible.
 193          */
 194         if (vma->vm_file &&
 195                 gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
 196                                                                 < policy_zone)
 197                         return 0;
 198         return 1;
 199 }
 200
 201 #else
 202
 203 struct mempolicy {};
 204
 205 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
 206 {
 207         return true;
 208 }
 209
 210 static inline void mpol_put(struct mempolicy *p)
 211 {
 212 }
 213
 214 static inline void mpol_cond_put(struct mempolicy *pol)
 215 {
 216 }
 217
 218 static inline struct mempolicy *mpol_cond_copy(struct mempolicy *to,
 219                                                 struct mempolicy *from)
 220 {
 221         return from;
 222 }
 223
 224 static inline void mpol_get(struct mempolicy *pol)
 225 {
 226 }
 227
 228 static inline struct mempolicy *mpol_dup(struct mempolicy *old)
 229 {
 230         return NULL;
 231 }
 232
 233 struct shared_policy {};
 234
 235 static inline int mpol_set_shared_policy(struct shared_policy *info,
 236                                         struct vm_area_struct *vma,
 237                                         struct mempolicy *new)
 238 {
 239         return -EINVAL;
 240 }
 241
 242 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 243                                                 struct mempolicy *mpol)
 244 {
 245 }
 246
 247 static inline void mpol_free_shared_policy(struct shared_policy *p)
 248 {
 249 }
 250
 251 static inline struct mempolicy *
 252 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 253 {
 254         return NULL;
 255 }
 256
 257 #define vma_policy(vma) NULL
 258 #define vma_set_policy(vma, pol) do {} while(0)
 259
 260 static inline void numa_policy_init(void)
 261 {
 262 }
 263
 264 static inline void numa_default_policy(void)
 265 {
 266 }
 267
 268 static inline void mpol_rebind_task(struct task_struct *tsk,
 269                                 const nodemask_t *new,
 270                                 enum mpol_rebind_step step)
 271 {
 272 }
 273
 274 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 275 {
 276 }
 277
 278 static inline void mpol_fix_fork_child_flag(struct task_struct *p)
 279 {
 280 }
 281
 282 static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 283                                 unsigned long addr, gfp_t gfp_flags,
 284                                 struct mempolicy **mpol, nodemask_t **nodemask)
 285 {
 286         *mpol = NULL;
 287         *nodemask = NULL;
 288         return node_zonelist(0, gfp_flags);
 289 }
 290
 291 static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
 292 {
 293         return false;
 294 }
 295
 296 static inline bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 297                         const nodemask_t *mask)
 298 {
 299         return false;
 300 }
 301
 302 static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 303                                    const nodemask_t *to, int flags)
 304 {
 305         return 0;
 306 }
 307
 308 static inline void check_highest_zone(int k)
 309 {
 310 }
 311
 312 #ifdef CONFIG_TMPFS
 313 static inline int mpol_parse_str(char *str, struct mempolicy **mpol,
 314                                 int no_context)
 315 {
 316         return 1;       /* error */
 317 }
 318 #endif
 319
 320 static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol,
 321                                 int no_context)
 322 {
 323         return 0;
 324 }
 325
 326 #endif /* CONFIG_NUMA */
 327 #endif