1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * NUMA memory policies for Linux. 4 * Copyright 2003,2004 Andi Kleen SuSE Labs 5 */ 6 #ifndef _LINUX_MEMPOLICY_H 7 #define _LINUX_MEMPOLICY_H 1 8 9 #include <linux/sched.h> 10 #include <linux/mmzone.h> 11 #include <linux/slab.h> 12 #include <linux/rbtree.h> 13 #include <linux/spinlock.h> 14 #include <linux/nodemask.h> 15 #include <linux/pagemap.h> 16 #include <uapi/linux/mempolicy.h> 17 18 struct mm_struct; 19 20 #define NO_INTERLEAVE_INDEX (-1UL) /* use task il_prev for interleaving */ 21 22 #ifdef CONFIG_NUMA 23 24 /* 25 * Describe a memory policy. 26 * 27 * A mempolicy can be either associated with a process or with a VMA. 28 * For VMA related allocations the VMA policy is preferred, otherwise 29 * the process policy is used. Interrupts ignore the memory policy 30 * of the current process. 31 * 32 * Locking policy for interleave: 33 * In process context there is no locking because only the process accesses 34 * its own state. All vma manipulation is somewhat protected by a down_read on 35 * mmap_lock. 36 * 37 * Freeing policy: 38 * Mempolicy objects are reference counted. A mempolicy will be freed when 39 * mpol_put() decrements the reference count to zero. 40 * 41 * Duplicating policy objects: 42 * mpol_dup() allocates a new mempolicy and copies the specified mempolicy 43 * to the new storage. The reference count of the new object is initialized 44 * to 1, representing the caller of mpol_dup(). 45 */ 46 struct mempolicy { 47 atomic_t refcnt; 48 unsigned short mode; /* See MPOL_* above */ 49 unsigned short flags; /* See set_mempolicy() MPOL_F_* above */ 50 nodemask_t nodes; /* interleave/bind/perfer */ 51 int home_node; /* Home node to use for MPOL_BIND and MPOL_PREFERRED_MANY */ 52 53 union { 54 nodemask_t cpuset_mems_allowed; /* relative to these nodes */ 55 nodemask_t user_nodemask; /* nodemask passed by user */ 56 } w; 57 }; 58 59 /* 60 * Support for managing mempolicy data objects (clone, copy, destroy) 61 * The default fast path of a NULL MPOL_DEFAULT policy is always inlined. 62 */ 63 64 extern void __mpol_put(struct mempolicy *pol); 65 static inline void mpol_put(struct mempolicy *pol) 66 { 67 if (pol) 68 __mpol_put(pol); 69 } 70 71 /* 72 * Does mempolicy pol need explicit unref after use? 73 * Currently only needed for shared policies. 74 */ 75 static inline int mpol_needs_cond_ref(struct mempolicy *pol) 76 { 77 return (pol && (pol->flags & MPOL_F_SHARED)); 78 } 79 80 static inline void mpol_cond_put(struct mempolicy *pol) 81 { 82 if (mpol_needs_cond_ref(pol)) 83 __mpol_put(pol); 84 } 85 86 extern struct mempolicy *__mpol_dup(struct mempolicy *pol); 87 static inline struct mempolicy *mpol_dup(struct mempolicy *pol) 88 { 89 if (pol) 90 pol = __mpol_dup(pol); 91 return pol; 92 } 93 94 static inline void mpol_get(struct mempolicy *pol) 95 { 96 if (pol) 97 atomic_inc(&pol->refcnt); 98 } 99 100 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b); 101 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b) 102 { 103 if (a == b) 104 return true; 105 return __mpol_equal(a, b); 106 } 107 108 /* 109 * Tree of shared policies for a shared memory region. 110 */ 111 struct shared_policy { 112 struct rb_root root; 113 rwlock_t lock; 114 }; 115 struct sp_node { 116 struct rb_node nd; 117 pgoff_t start, end; 118 struct mempolicy *policy; 119 }; 120 121 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst); 122 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol); 123 int mpol_set_shared_policy(struct shared_policy *sp, 124 struct vm_area_struct *vma, struct mempolicy *mpol); 125 void mpol_free_shared_policy(struct shared_policy *sp); 126 struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp, 127 pgoff_t idx); 128 129 struct mempolicy *get_task_policy(struct task_struct *p); 130 struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, 131 unsigned long addr, pgoff_t *ilx); 132 struct mempolicy *get_vma_policy(struct vm_area_struct *vma, 133 unsigned long addr, int order, pgoff_t *ilx); 134 bool vma_policy_mof(struct vm_area_struct *vma); 135 136 extern void numa_default_policy(void); 137 extern void numa_policy_init(void); 138 extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new); 139 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new); 140 141 extern int huge_node(struct vm_area_struct *vma, 142 unsigned long addr, gfp_t gfp_flags, 143 struct mempolicy **mpol, nodemask_t **nodemask); 144 extern bool init_nodemask_of_mempolicy(nodemask_t *mask); 145 extern bool mempolicy_in_oom_domain(struct task_struct *tsk, 146 const nodemask_t *mask); 147 extern unsigned int mempolicy_slab_node(void); 148 149 extern enum zone_type policy_zone; 150 151 static inline void check_highest_zone(enum zone_type k) 152 { 153 if (k > policy_zone && k != ZONE_MOVABLE) 154 policy_zone = k; 155 } 156 157 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, 158 const nodemask_t *to, int flags); 159 160 161 #ifdef CONFIG_TMPFS 162 extern int mpol_parse_str(char *str, struct mempolicy **mpol); 163 #endif 164 165 extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol); 166 167 /* Check if a vma is migratable */ 168 extern bool vma_migratable(struct vm_area_struct *vma); 169 170 int mpol_misplaced(struct folio *, struct vm_area_struct *, unsigned long); 171 extern void mpol_put_task_policy(struct task_struct *); 172 173 static inline bool mpol_is_preferred_many(struct mempolicy *pol) 174 { 175 return (pol->mode == MPOL_PREFERRED_MANY); 176 } 177 178 extern bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone); 179 180 #else 181 182 struct mempolicy {}; 183 184 static inline struct mempolicy *get_task_policy(struct task_struct *p) 185 { 186 return NULL; 187 } 188 189 static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b) 190 { 191 return true; 192 } 193 194 static inline void mpol_put(struct mempolicy *pol) 195 { 196 } 197 198 static inline void mpol_cond_put(struct mempolicy *pol) 199 { 200 } 201 202 static inline void mpol_get(struct mempolicy *pol) 203 { 204 } 205 206 struct shared_policy {}; 207 208 static inline void mpol_shared_policy_init(struct shared_policy *sp, 209 struct mempolicy *mpol) 210 { 211 } 212 213 static inline void mpol_free_shared_policy(struct shared_policy *sp) 214 { 215 } 216 217 static inline struct mempolicy * 218 mpol_shared_policy_lookup(struct shared_policy *sp, pgoff_t idx) 219 { 220 return NULL; 221 } 222 223 static inline struct mempolicy *get_vma_policy(struct vm_area_struct *vma, 224 unsigned long addr, int order, pgoff_t *ilx) 225 { 226 *ilx = 0; 227 return NULL; 228 } 229 230 static inline int 231 vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) 232 { 233 return 0; 234 } 235 236 static inline void numa_policy_init(void) 237 { 238 } 239 240 static inline void numa_default_policy(void) 241 { 242 } 243 244 static inline void mpol_rebind_task(struct task_struct *tsk, 245 const nodemask_t *new) 246 { 247 } 248 249 static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) 250 { 251 } 252 253 static inline int huge_node(struct vm_area_struct *vma, 254 unsigned long addr, gfp_t gfp_flags, 255 struct mempolicy **mpol, nodemask_t **nodemask) 256 { 257 *mpol = NULL; 258 *nodemask = NULL; 259 return 0; 260 } 261 262 static inline bool init_nodemask_of_mempolicy(nodemask_t *m) 263 { 264 return false; 265 } 266 267 static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, 268 const nodemask_t *to, int flags) 269 { 270 return 0; 271 } 272 273 static inline void check_highest_zone(int k) 274 { 275 } 276 277 #ifdef CONFIG_TMPFS 278 static inline int mpol_parse_str(char *str, struct mempolicy **mpol) 279 { 280 return 1; /* error */ 281 } 282 #endif 283 284 static inline int mpol_misplaced(struct folio *folio, 285 struct vm_area_struct *vma, 286 unsigned long address) 287 { 288 return -1; /* no node preference */ 289 } 290 291 static inline void mpol_put_task_policy(struct task_struct *task) 292 { 293 } 294 295 static inline bool mpol_is_preferred_many(struct mempolicy *pol) 296 { 297 return false; 298 } 299 300 #endif /* CONFIG_NUMA */ 301 #endif 302