| 1 | /* |
| 2 | * Simple NUMA memory policy for the Linux kernel. |
| 3 | * |
| 4 | * Copyright 2003,2004 Andi Kleen, SuSE Labs. |
| 5 | * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc. |
| 6 | * Subject to the GNU Public License, version 2. |
| 7 | * |
| 8 | * NUMA policy allows the user to give hints in which node(s) memory should |
| 9 | * be allocated. |
| 10 | * |
| 11 | * Support four policies per VMA and per process: |
| 12 | * |
| 13 | * The VMA policy has priority over the process policy for a page fault. |
| 14 | * |
| 15 | * interleave Allocate memory interleaved over a set of nodes, |
| 16 | * with normal fallback if it fails. |
| 17 | * For VMA based allocations this interleaves based on the |
| 18 | * offset into the backing object or offset into the mapping |
| 19 | * for anonymous memory. For process policy an process counter |
| 20 | * is used. |
| 21 | * |
| 22 | * bind Only allocate memory on a specific set of nodes, |
| 23 | * no fallback. |
| 24 | * FIXME: memory is allocated starting with the first node |
| 25 | * to the last. It would be better if bind would truly restrict |
| 26 | * the allocation to memory nodes instead |
| 27 | * |
| 28 | * preferred Try a specific node first before normal fallback. |
| 29 | * As a special case node -1 here means do the allocation |
| 30 | * on the local CPU. This is normally identical to default, |
| 31 | * but useful to set in a VMA when you have a non default |
| 32 | * process policy. |
| 33 | * |
| 34 | * default Allocate on the local node first, or when on a VMA |
| 35 | * use the process policy. This is what Linux always did |
| 36 | * in a NUMA aware kernel and still does by, ahem, default. |
| 37 | * |
| 38 | * The process policy is applied for most non interrupt memory allocations |
| 39 | * in that process' context. Interrupts ignore the policies and always |
| 40 | * try to allocate on the local CPU. The VMA policy is only applied for memory |
| 41 | * allocations for a VMA in the VM. |
| 42 | * |
| 43 | * Currently there are a few corner cases in swapping where the policy |
| 44 | * is not applied, but the majority should be handled. When process policy |
| 45 | * is used it is not remembered over swap outs/swap ins. |
| 46 | * |
| 47 | * Only the highest zone in the zone hierarchy gets policied. Allocations |
| 48 | * requesting a lower zone just use default policy. This implies that |
| 49 | * on systems with highmem kernel lowmem allocation don't get policied. |
| 50 | * Same with GFP_DMA allocations. |
| 51 | * |
| 52 | * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between |
| 53 | * all users and remembered even when nobody has memory mapped. |
| 54 | */ |
| 55 | |
| 56 | /* Notebook: |
| 57 | fix mmap readahead to honour policy and enable policy for any page cache |
| 58 | object |
| 59 | statistics for bigpages |
| 60 | global policy for page cache? currently it uses process policy. Requires |
| 61 | first item above. |
| 62 | handle mremap for shared memory (currently ignored for the policy) |
| 63 | grows down? |
| 64 | make bind policy root only? It can trigger oom much faster and the |
| 65 | kernel is not always grateful with that. |
| 66 | */ |
| 67 | |
| 68 | #include <linux/mempolicy.h> |
| 69 | #include <linux/mm.h> |
| 70 | #include <linux/highmem.h> |
| 71 | #include <linux/hugetlb.h> |
| 72 | #include <linux/kernel.h> |
| 73 | #include <linux/sched.h> |
| 74 | #include <linux/nodemask.h> |
| 75 | #include <linux/cpuset.h> |
| 76 | #include <linux/slab.h> |
| 77 | #include <linux/string.h> |
| 78 | #include <linux/export.h> |
| 79 | #include <linux/nsproxy.h> |
| 80 | #include <linux/interrupt.h> |
| 81 | #include <linux/init.h> |
| 82 | #include <linux/compat.h> |
| 83 | #include <linux/swap.h> |
| 84 | #include <linux/seq_file.h> |
| 85 | #include <linux/proc_fs.h> |
| 86 | #include <linux/migrate.h> |
| 87 | #include <linux/ksm.h> |
| 88 | #include <linux/rmap.h> |
| 89 | #include <linux/security.h> |
| 90 | #include <linux/syscalls.h> |
| 91 | #include <linux/ctype.h> |
| 92 | #include <linux/mm_inline.h> |
| 93 | |
| 94 | #include <asm/tlbflush.h> |
| 95 | #include <asm/uaccess.h> |
| 96 | #include <linux/random.h> |
| 97 | |
| 98 | #include "internal.h" |
| 99 | |
| 100 | /* Internal flags */ |
| 101 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ |
| 102 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ |
| 103 | |
| 104 | static struct kmem_cache *policy_cache; |
| 105 | static struct kmem_cache *sn_cache; |
| 106 | |
| 107 | /* Highest zone. An specific allocation for a zone below that is not |
| 108 | policied. */ |
| 109 | enum zone_type policy_zone = 0; |
| 110 | |
| 111 | /* |
| 112 | * run-time system-wide default policy => local allocation |
| 113 | */ |
| 114 | static struct mempolicy default_policy = { |
| 115 | .refcnt = ATOMIC_INIT(1), /* never free it */ |
| 116 | .mode = MPOL_PREFERRED, |
| 117 | .flags = MPOL_F_LOCAL, |
| 118 | }; |
| 119 | |
| 120 | static const struct mempolicy_operations { |
| 121 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); |
| 122 | /* |
| 123 | * If read-side task has no lock to protect task->mempolicy, write-side |
| 124 | * task will rebind the task->mempolicy by two step. The first step is |
| 125 | * setting all the newly nodes, and the second step is cleaning all the |
| 126 | * disallowed nodes. In this way, we can avoid finding no node to alloc |
| 127 | * page. |
| 128 | * If we have a lock to protect task->mempolicy in read-side, we do |
| 129 | * rebind directly. |
| 130 | * |
| 131 | * step: |
| 132 | * MPOL_REBIND_ONCE - do rebind work at once |
| 133 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 134 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 135 | */ |
| 136 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes, |
| 137 | enum mpol_rebind_step step); |
| 138 | } mpol_ops[MPOL_MAX]; |
| 139 | |
| 140 | /* Check that the nodemask contains at least one populated zone */ |
| 141 | static int is_valid_nodemask(const nodemask_t *nodemask) |
| 142 | { |
| 143 | int nd, k; |
| 144 | |
| 145 | for_each_node_mask(nd, *nodemask) { |
| 146 | struct zone *z; |
| 147 | |
| 148 | for (k = 0; k <= policy_zone; k++) { |
| 149 | z = &NODE_DATA(nd)->node_zones[k]; |
| 150 | if (z->present_pages > 0) |
| 151 | return 1; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) |
| 159 | { |
| 160 | return pol->flags & MPOL_MODE_FLAGS; |
| 161 | } |
| 162 | |
| 163 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, |
| 164 | const nodemask_t *rel) |
| 165 | { |
| 166 | nodemask_t tmp; |
| 167 | nodes_fold(tmp, *orig, nodes_weight(*rel)); |
| 168 | nodes_onto(*ret, tmp, *rel); |
| 169 | } |
| 170 | |
| 171 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) |
| 172 | { |
| 173 | if (nodes_empty(*nodes)) |
| 174 | return -EINVAL; |
| 175 | pol->v.nodes = *nodes; |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) |
| 180 | { |
| 181 | if (!nodes) |
| 182 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ |
| 183 | else if (nodes_empty(*nodes)) |
| 184 | return -EINVAL; /* no allowed nodes */ |
| 185 | else |
| 186 | pol->v.preferred_node = first_node(*nodes); |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) |
| 191 | { |
| 192 | if (!is_valid_nodemask(nodes)) |
| 193 | return -EINVAL; |
| 194 | pol->v.nodes = *nodes; |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if |
| 200 | * any, for the new policy. mpol_new() has already validated the nodes |
| 201 | * parameter with respect to the policy mode and flags. But, we need to |
| 202 | * handle an empty nodemask with MPOL_PREFERRED here. |
| 203 | * |
| 204 | * Must be called holding task's alloc_lock to protect task's mems_allowed |
| 205 | * and mempolicy. May also be called holding the mmap_semaphore for write. |
| 206 | */ |
| 207 | static int mpol_set_nodemask(struct mempolicy *pol, |
| 208 | const nodemask_t *nodes, struct nodemask_scratch *nsc) |
| 209 | { |
| 210 | int ret; |
| 211 | |
| 212 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ |
| 213 | if (pol == NULL) |
| 214 | return 0; |
| 215 | /* Check N_HIGH_MEMORY */ |
| 216 | nodes_and(nsc->mask1, |
| 217 | cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]); |
| 218 | |
| 219 | VM_BUG_ON(!nodes); |
| 220 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) |
| 221 | nodes = NULL; /* explicit local allocation */ |
| 222 | else { |
| 223 | if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 224 | mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1); |
| 225 | else |
| 226 | nodes_and(nsc->mask2, *nodes, nsc->mask1); |
| 227 | |
| 228 | if (mpol_store_user_nodemask(pol)) |
| 229 | pol->w.user_nodemask = *nodes; |
| 230 | else |
| 231 | pol->w.cpuset_mems_allowed = |
| 232 | cpuset_current_mems_allowed; |
| 233 | } |
| 234 | |
| 235 | if (nodes) |
| 236 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); |
| 237 | else |
| 238 | ret = mpol_ops[pol->mode].create(pol, NULL); |
| 239 | return ret; |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * This function just creates a new policy, does some check and simple |
| 244 | * initialization. You must invoke mpol_set_nodemask() to set nodes. |
| 245 | */ |
| 246 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, |
| 247 | nodemask_t *nodes) |
| 248 | { |
| 249 | struct mempolicy *policy; |
| 250 | |
| 251 | pr_debug("setting mode %d flags %d nodes[0] %lx\n", |
| 252 | mode, flags, nodes ? nodes_addr(*nodes)[0] : -1); |
| 253 | |
| 254 | if (mode == MPOL_DEFAULT) { |
| 255 | if (nodes && !nodes_empty(*nodes)) |
| 256 | return ERR_PTR(-EINVAL); |
| 257 | return NULL; /* simply delete any existing policy */ |
| 258 | } |
| 259 | VM_BUG_ON(!nodes); |
| 260 | |
| 261 | /* |
| 262 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or |
| 263 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). |
| 264 | * All other modes require a valid pointer to a non-empty nodemask. |
| 265 | */ |
| 266 | if (mode == MPOL_PREFERRED) { |
| 267 | if (nodes_empty(*nodes)) { |
| 268 | if (((flags & MPOL_F_STATIC_NODES) || |
| 269 | (flags & MPOL_F_RELATIVE_NODES))) |
| 270 | return ERR_PTR(-EINVAL); |
| 271 | } |
| 272 | } else if (nodes_empty(*nodes)) |
| 273 | return ERR_PTR(-EINVAL); |
| 274 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 275 | if (!policy) |
| 276 | return ERR_PTR(-ENOMEM); |
| 277 | atomic_set(&policy->refcnt, 1); |
| 278 | policy->mode = mode; |
| 279 | policy->flags = flags; |
| 280 | |
| 281 | return policy; |
| 282 | } |
| 283 | |
| 284 | /* Slow path of a mpol destructor. */ |
| 285 | void __mpol_put(struct mempolicy *p) |
| 286 | { |
| 287 | if (!atomic_dec_and_test(&p->refcnt)) |
| 288 | return; |
| 289 | kmem_cache_free(policy_cache, p); |
| 290 | } |
| 291 | |
| 292 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes, |
| 293 | enum mpol_rebind_step step) |
| 294 | { |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * step: |
| 299 | * MPOL_REBIND_ONCE - do rebind work at once |
| 300 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 301 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 302 | */ |
| 303 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, |
| 304 | enum mpol_rebind_step step) |
| 305 | { |
| 306 | nodemask_t tmp; |
| 307 | |
| 308 | if (pol->flags & MPOL_F_STATIC_NODES) |
| 309 | nodes_and(tmp, pol->w.user_nodemask, *nodes); |
| 310 | else if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 311 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
| 312 | else { |
| 313 | /* |
| 314 | * if step == 1, we use ->w.cpuset_mems_allowed to cache the |
| 315 | * result |
| 316 | */ |
| 317 | if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) { |
| 318 | nodes_remap(tmp, pol->v.nodes, |
| 319 | pol->w.cpuset_mems_allowed, *nodes); |
| 320 | pol->w.cpuset_mems_allowed = step ? tmp : *nodes; |
| 321 | } else if (step == MPOL_REBIND_STEP2) { |
| 322 | tmp = pol->w.cpuset_mems_allowed; |
| 323 | pol->w.cpuset_mems_allowed = *nodes; |
| 324 | } else |
| 325 | BUG(); |
| 326 | } |
| 327 | |
| 328 | if (nodes_empty(tmp)) |
| 329 | tmp = *nodes; |
| 330 | |
| 331 | if (step == MPOL_REBIND_STEP1) |
| 332 | nodes_or(pol->v.nodes, pol->v.nodes, tmp); |
| 333 | else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2) |
| 334 | pol->v.nodes = tmp; |
| 335 | else |
| 336 | BUG(); |
| 337 | |
| 338 | if (!node_isset(current->il_next, tmp)) { |
| 339 | current->il_next = next_node(current->il_next, tmp); |
| 340 | if (current->il_next >= MAX_NUMNODES) |
| 341 | current->il_next = first_node(tmp); |
| 342 | if (current->il_next >= MAX_NUMNODES) |
| 343 | current->il_next = numa_node_id(); |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | static void mpol_rebind_preferred(struct mempolicy *pol, |
| 348 | const nodemask_t *nodes, |
| 349 | enum mpol_rebind_step step) |
| 350 | { |
| 351 | nodemask_t tmp; |
| 352 | |
| 353 | if (pol->flags & MPOL_F_STATIC_NODES) { |
| 354 | int node = first_node(pol->w.user_nodemask); |
| 355 | |
| 356 | if (node_isset(node, *nodes)) { |
| 357 | pol->v.preferred_node = node; |
| 358 | pol->flags &= ~MPOL_F_LOCAL; |
| 359 | } else |
| 360 | pol->flags |= MPOL_F_LOCAL; |
| 361 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { |
| 362 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
| 363 | pol->v.preferred_node = first_node(tmp); |
| 364 | } else if (!(pol->flags & MPOL_F_LOCAL)) { |
| 365 | pol->v.preferred_node = node_remap(pol->v.preferred_node, |
| 366 | pol->w.cpuset_mems_allowed, |
| 367 | *nodes); |
| 368 | pol->w.cpuset_mems_allowed = *nodes; |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * mpol_rebind_policy - Migrate a policy to a different set of nodes |
| 374 | * |
| 375 | * If read-side task has no lock to protect task->mempolicy, write-side |
| 376 | * task will rebind the task->mempolicy by two step. The first step is |
| 377 | * setting all the newly nodes, and the second step is cleaning all the |
| 378 | * disallowed nodes. In this way, we can avoid finding no node to alloc |
| 379 | * page. |
| 380 | * If we have a lock to protect task->mempolicy in read-side, we do |
| 381 | * rebind directly. |
| 382 | * |
| 383 | * step: |
| 384 | * MPOL_REBIND_ONCE - do rebind work at once |
| 385 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 386 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 387 | */ |
| 388 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, |
| 389 | enum mpol_rebind_step step) |
| 390 | { |
| 391 | if (!pol) |
| 392 | return; |
| 393 | if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE && |
| 394 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) |
| 395 | return; |
| 396 | |
| 397 | if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING)) |
| 398 | return; |
| 399 | |
| 400 | if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING)) |
| 401 | BUG(); |
| 402 | |
| 403 | if (step == MPOL_REBIND_STEP1) |
| 404 | pol->flags |= MPOL_F_REBINDING; |
| 405 | else if (step == MPOL_REBIND_STEP2) |
| 406 | pol->flags &= ~MPOL_F_REBINDING; |
| 407 | else if (step >= MPOL_REBIND_NSTEP) |
| 408 | BUG(); |
| 409 | |
| 410 | mpol_ops[pol->mode].rebind(pol, newmask, step); |
| 411 | } |
| 412 | |
| 413 | /* |
| 414 | * Wrapper for mpol_rebind_policy() that just requires task |
| 415 | * pointer, and updates task mempolicy. |
| 416 | * |
| 417 | * Called with task's alloc_lock held. |
| 418 | */ |
| 419 | |
| 420 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, |
| 421 | enum mpol_rebind_step step) |
| 422 | { |
| 423 | mpol_rebind_policy(tsk->mempolicy, new, step); |
| 424 | } |
| 425 | |
| 426 | /* |
| 427 | * Rebind each vma in mm to new nodemask. |
| 428 | * |
| 429 | * Call holding a reference to mm. Takes mm->mmap_sem during call. |
| 430 | */ |
| 431 | |
| 432 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) |
| 433 | { |
| 434 | struct vm_area_struct *vma; |
| 435 | |
| 436 | down_write(&mm->mmap_sem); |
| 437 | for (vma = mm->mmap; vma; vma = vma->vm_next) |
| 438 | mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); |
| 439 | up_write(&mm->mmap_sem); |
| 440 | } |
| 441 | |
| 442 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { |
| 443 | [MPOL_DEFAULT] = { |
| 444 | .rebind = mpol_rebind_default, |
| 445 | }, |
| 446 | [MPOL_INTERLEAVE] = { |
| 447 | .create = mpol_new_interleave, |
| 448 | .rebind = mpol_rebind_nodemask, |
| 449 | }, |
| 450 | [MPOL_PREFERRED] = { |
| 451 | .create = mpol_new_preferred, |
| 452 | .rebind = mpol_rebind_preferred, |
| 453 | }, |
| 454 | [MPOL_BIND] = { |
| 455 | .create = mpol_new_bind, |
| 456 | .rebind = mpol_rebind_nodemask, |
| 457 | }, |
| 458 | }; |
| 459 | |
| 460 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 461 | unsigned long flags); |
| 462 | |
| 463 | /* Scan through pages checking if pages follow certain conditions. */ |
| 464 | static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
| 465 | unsigned long addr, unsigned long end, |
| 466 | const nodemask_t *nodes, unsigned long flags, |
| 467 | void *private) |
| 468 | { |
| 469 | pte_t *orig_pte; |
| 470 | pte_t *pte; |
| 471 | spinlock_t *ptl; |
| 472 | |
| 473 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
| 474 | do { |
| 475 | struct page *page; |
| 476 | int nid; |
| 477 | |
| 478 | if (!pte_present(*pte)) |
| 479 | continue; |
| 480 | page = vm_normal_page(vma, addr, *pte); |
| 481 | if (!page) |
| 482 | continue; |
| 483 | /* |
| 484 | * vm_normal_page() filters out zero pages, but there might |
| 485 | * still be PageReserved pages to skip, perhaps in a VDSO. |
| 486 | * And we cannot move PageKsm pages sensibly or safely yet. |
| 487 | */ |
| 488 | if (PageReserved(page) || PageKsm(page)) |
| 489 | continue; |
| 490 | nid = page_to_nid(page); |
| 491 | if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) |
| 492 | continue; |
| 493 | |
| 494 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 495 | migrate_page_add(page, private, flags); |
| 496 | else |
| 497 | break; |
| 498 | } while (pte++, addr += PAGE_SIZE, addr != end); |
| 499 | pte_unmap_unlock(orig_pte, ptl); |
| 500 | return addr != end; |
| 501 | } |
| 502 | |
| 503 | static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, |
| 504 | unsigned long addr, unsigned long end, |
| 505 | const nodemask_t *nodes, unsigned long flags, |
| 506 | void *private) |
| 507 | { |
| 508 | pmd_t *pmd; |
| 509 | unsigned long next; |
| 510 | |
| 511 | pmd = pmd_offset(pud, addr); |
| 512 | do { |
| 513 | next = pmd_addr_end(addr, end); |
| 514 | split_huge_page_pmd(vma->vm_mm, pmd); |
| 515 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) |
| 516 | continue; |
| 517 | if (check_pte_range(vma, pmd, addr, next, nodes, |
| 518 | flags, private)) |
| 519 | return -EIO; |
| 520 | } while (pmd++, addr = next, addr != end); |
| 521 | return 0; |
| 522 | } |
| 523 | |
| 524 | static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, |
| 525 | unsigned long addr, unsigned long end, |
| 526 | const nodemask_t *nodes, unsigned long flags, |
| 527 | void *private) |
| 528 | { |
| 529 | pud_t *pud; |
| 530 | unsigned long next; |
| 531 | |
| 532 | pud = pud_offset(pgd, addr); |
| 533 | do { |
| 534 | next = pud_addr_end(addr, end); |
| 535 | if (pud_none_or_clear_bad(pud)) |
| 536 | continue; |
| 537 | if (check_pmd_range(vma, pud, addr, next, nodes, |
| 538 | flags, private)) |
| 539 | return -EIO; |
| 540 | } while (pud++, addr = next, addr != end); |
| 541 | return 0; |
| 542 | } |
| 543 | |
| 544 | static inline int check_pgd_range(struct vm_area_struct *vma, |
| 545 | unsigned long addr, unsigned long end, |
| 546 | const nodemask_t *nodes, unsigned long flags, |
| 547 | void *private) |
| 548 | { |
| 549 | pgd_t *pgd; |
| 550 | unsigned long next; |
| 551 | |
| 552 | pgd = pgd_offset(vma->vm_mm, addr); |
| 553 | do { |
| 554 | next = pgd_addr_end(addr, end); |
| 555 | if (pgd_none_or_clear_bad(pgd)) |
| 556 | continue; |
| 557 | if (check_pud_range(vma, pgd, addr, next, nodes, |
| 558 | flags, private)) |
| 559 | return -EIO; |
| 560 | } while (pgd++, addr = next, addr != end); |
| 561 | return 0; |
| 562 | } |
| 563 | |
| 564 | /* |
| 565 | * Check if all pages in a range are on a set of nodes. |
| 566 | * If pagelist != NULL then isolate pages from the LRU and |
| 567 | * put them on the pagelist. |
| 568 | */ |
| 569 | static struct vm_area_struct * |
| 570 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, |
| 571 | const nodemask_t *nodes, unsigned long flags, void *private) |
| 572 | { |
| 573 | int err; |
| 574 | struct vm_area_struct *first, *vma, *prev; |
| 575 | |
| 576 | |
| 577 | first = find_vma(mm, start); |
| 578 | if (!first) |
| 579 | return ERR_PTR(-EFAULT); |
| 580 | prev = NULL; |
| 581 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { |
| 582 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { |
| 583 | if (!vma->vm_next && vma->vm_end < end) |
| 584 | return ERR_PTR(-EFAULT); |
| 585 | if (prev && prev->vm_end < vma->vm_start) |
| 586 | return ERR_PTR(-EFAULT); |
| 587 | } |
| 588 | if (!is_vm_hugetlb_page(vma) && |
| 589 | ((flags & MPOL_MF_STRICT) || |
| 590 | ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && |
| 591 | vma_migratable(vma)))) { |
| 592 | unsigned long endvma = vma->vm_end; |
| 593 | |
| 594 | if (endvma > end) |
| 595 | endvma = end; |
| 596 | if (vma->vm_start > start) |
| 597 | start = vma->vm_start; |
| 598 | err = check_pgd_range(vma, start, endvma, nodes, |
| 599 | flags, private); |
| 600 | if (err) { |
| 601 | first = ERR_PTR(err); |
| 602 | break; |
| 603 | } |
| 604 | } |
| 605 | prev = vma; |
| 606 | } |
| 607 | return first; |
| 608 | } |
| 609 | |
| 610 | /* |
| 611 | * Apply policy to a single VMA |
| 612 | * This must be called with the mmap_sem held for writing. |
| 613 | */ |
| 614 | static int vma_replace_policy(struct vm_area_struct *vma, |
| 615 | struct mempolicy *pol) |
| 616 | { |
| 617 | int err; |
| 618 | struct mempolicy *old; |
| 619 | struct mempolicy *new; |
| 620 | |
| 621 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", |
| 622 | vma->vm_start, vma->vm_end, vma->vm_pgoff, |
| 623 | vma->vm_ops, vma->vm_file, |
| 624 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); |
| 625 | |
| 626 | new = mpol_dup(pol); |
| 627 | if (IS_ERR(new)) |
| 628 | return PTR_ERR(new); |
| 629 | |
| 630 | if (vma->vm_ops && vma->vm_ops->set_policy) { |
| 631 | err = vma->vm_ops->set_policy(vma, new); |
| 632 | if (err) |
| 633 | goto err_out; |
| 634 | } |
| 635 | |
| 636 | old = vma->vm_policy; |
| 637 | vma->vm_policy = new; /* protected by mmap_sem */ |
| 638 | mpol_put(old); |
| 639 | |
| 640 | return 0; |
| 641 | err_out: |
| 642 | mpol_put(new); |
| 643 | return err; |
| 644 | } |
| 645 | |
| 646 | /* Step 2: apply policy to a range and do splits. */ |
| 647 | static int mbind_range(struct mm_struct *mm, unsigned long start, |
| 648 | unsigned long end, struct mempolicy *new_pol) |
| 649 | { |
| 650 | struct vm_area_struct *next; |
| 651 | struct vm_area_struct *prev; |
| 652 | struct vm_area_struct *vma; |
| 653 | int err = 0; |
| 654 | pgoff_t pgoff; |
| 655 | unsigned long vmstart; |
| 656 | unsigned long vmend; |
| 657 | |
| 658 | vma = find_vma(mm, start); |
| 659 | if (!vma || vma->vm_start > start) |
| 660 | return -EFAULT; |
| 661 | |
| 662 | prev = vma->vm_prev; |
| 663 | if (start > vma->vm_start) |
| 664 | prev = vma; |
| 665 | |
| 666 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { |
| 667 | next = vma->vm_next; |
| 668 | vmstart = max(start, vma->vm_start); |
| 669 | vmend = min(end, vma->vm_end); |
| 670 | |
| 671 | if (mpol_equal(vma_policy(vma), new_pol)) |
| 672 | continue; |
| 673 | |
| 674 | pgoff = vma->vm_pgoff + |
| 675 | ((vmstart - vma->vm_start) >> PAGE_SHIFT); |
| 676 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, |
| 677 | vma->anon_vma, vma->vm_file, pgoff, |
| 678 | new_pol); |
| 679 | if (prev) { |
| 680 | vma = prev; |
| 681 | next = vma->vm_next; |
| 682 | continue; |
| 683 | } |
| 684 | if (vma->vm_start != vmstart) { |
| 685 | err = split_vma(vma->vm_mm, vma, vmstart, 1); |
| 686 | if (err) |
| 687 | goto out; |
| 688 | } |
| 689 | if (vma->vm_end != vmend) { |
| 690 | err = split_vma(vma->vm_mm, vma, vmend, 0); |
| 691 | if (err) |
| 692 | goto out; |
| 693 | } |
| 694 | err = vma_replace_policy(vma, new_pol); |
| 695 | if (err) |
| 696 | goto out; |
| 697 | } |
| 698 | |
| 699 | out: |
| 700 | return err; |
| 701 | } |
| 702 | |
| 703 | /* |
| 704 | * Update task->flags PF_MEMPOLICY bit: set iff non-default |
| 705 | * mempolicy. Allows more rapid checking of this (combined perhaps |
| 706 | * with other PF_* flag bits) on memory allocation hot code paths. |
| 707 | * |
| 708 | * If called from outside this file, the task 'p' should -only- be |
| 709 | * a newly forked child not yet visible on the task list, because |
| 710 | * manipulating the task flags of a visible task is not safe. |
| 711 | * |
| 712 | * The above limitation is why this routine has the funny name |
| 713 | * mpol_fix_fork_child_flag(). |
| 714 | * |
| 715 | * It is also safe to call this with a task pointer of current, |
| 716 | * which the static wrapper mpol_set_task_struct_flag() does, |
| 717 | * for use within this file. |
| 718 | */ |
| 719 | |
| 720 | void mpol_fix_fork_child_flag(struct task_struct *p) |
| 721 | { |
| 722 | if (p->mempolicy) |
| 723 | p->flags |= PF_MEMPOLICY; |
| 724 | else |
| 725 | p->flags &= ~PF_MEMPOLICY; |
| 726 | } |
| 727 | |
| 728 | static void mpol_set_task_struct_flag(void) |
| 729 | { |
| 730 | mpol_fix_fork_child_flag(current); |
| 731 | } |
| 732 | |
| 733 | /* Set the process memory policy */ |
| 734 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, |
| 735 | nodemask_t *nodes) |
| 736 | { |
| 737 | struct mempolicy *new, *old; |
| 738 | struct mm_struct *mm = current->mm; |
| 739 | NODEMASK_SCRATCH(scratch); |
| 740 | int ret; |
| 741 | |
| 742 | if (!scratch) |
| 743 | return -ENOMEM; |
| 744 | |
| 745 | new = mpol_new(mode, flags, nodes); |
| 746 | if (IS_ERR(new)) { |
| 747 | ret = PTR_ERR(new); |
| 748 | goto out; |
| 749 | } |
| 750 | /* |
| 751 | * prevent changing our mempolicy while show_numa_maps() |
| 752 | * is using it. |
| 753 | * Note: do_set_mempolicy() can be called at init time |
| 754 | * with no 'mm'. |
| 755 | */ |
| 756 | if (mm) |
| 757 | down_write(&mm->mmap_sem); |
| 758 | task_lock(current); |
| 759 | ret = mpol_set_nodemask(new, nodes, scratch); |
| 760 | if (ret) { |
| 761 | task_unlock(current); |
| 762 | if (mm) |
| 763 | up_write(&mm->mmap_sem); |
| 764 | mpol_put(new); |
| 765 | goto out; |
| 766 | } |
| 767 | old = current->mempolicy; |
| 768 | current->mempolicy = new; |
| 769 | mpol_set_task_struct_flag(); |
| 770 | if (new && new->mode == MPOL_INTERLEAVE && |
| 771 | nodes_weight(new->v.nodes)) |
| 772 | current->il_next = first_node(new->v.nodes); |
| 773 | task_unlock(current); |
| 774 | if (mm) |
| 775 | up_write(&mm->mmap_sem); |
| 776 | |
| 777 | mpol_put(old); |
| 778 | ret = 0; |
| 779 | out: |
| 780 | NODEMASK_SCRATCH_FREE(scratch); |
| 781 | return ret; |
| 782 | } |
| 783 | |
| 784 | /* |
| 785 | * Return nodemask for policy for get_mempolicy() query |
| 786 | * |
| 787 | * Called with task's alloc_lock held |
| 788 | */ |
| 789 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) |
| 790 | { |
| 791 | nodes_clear(*nodes); |
| 792 | if (p == &default_policy) |
| 793 | return; |
| 794 | |
| 795 | switch (p->mode) { |
| 796 | case MPOL_BIND: |
| 797 | /* Fall through */ |
| 798 | case MPOL_INTERLEAVE: |
| 799 | *nodes = p->v.nodes; |
| 800 | break; |
| 801 | case MPOL_PREFERRED: |
| 802 | if (!(p->flags & MPOL_F_LOCAL)) |
| 803 | node_set(p->v.preferred_node, *nodes); |
| 804 | /* else return empty node mask for local allocation */ |
| 805 | break; |
| 806 | default: |
| 807 | BUG(); |
| 808 | } |
| 809 | } |
| 810 | |
| 811 | static int lookup_node(struct mm_struct *mm, unsigned long addr) |
| 812 | { |
| 813 | struct page *p; |
| 814 | int err; |
| 815 | |
| 816 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); |
| 817 | if (err >= 0) { |
| 818 | err = page_to_nid(p); |
| 819 | put_page(p); |
| 820 | } |
| 821 | return err; |
| 822 | } |
| 823 | |
| 824 | /* Retrieve NUMA policy */ |
| 825 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, |
| 826 | unsigned long addr, unsigned long flags) |
| 827 | { |
| 828 | int err; |
| 829 | struct mm_struct *mm = current->mm; |
| 830 | struct vm_area_struct *vma = NULL; |
| 831 | struct mempolicy *pol = current->mempolicy; |
| 832 | |
| 833 | if (flags & |
| 834 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) |
| 835 | return -EINVAL; |
| 836 | |
| 837 | if (flags & MPOL_F_MEMS_ALLOWED) { |
| 838 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) |
| 839 | return -EINVAL; |
| 840 | *policy = 0; /* just so it's initialized */ |
| 841 | task_lock(current); |
| 842 | *nmask = cpuset_current_mems_allowed; |
| 843 | task_unlock(current); |
| 844 | return 0; |
| 845 | } |
| 846 | |
| 847 | if (flags & MPOL_F_ADDR) { |
| 848 | /* |
| 849 | * Do NOT fall back to task policy if the |
| 850 | * vma/shared policy at addr is NULL. We |
| 851 | * want to return MPOL_DEFAULT in this case. |
| 852 | */ |
| 853 | down_read(&mm->mmap_sem); |
| 854 | vma = find_vma_intersection(mm, addr, addr+1); |
| 855 | if (!vma) { |
| 856 | up_read(&mm->mmap_sem); |
| 857 | return -EFAULT; |
| 858 | } |
| 859 | if (vma->vm_ops && vma->vm_ops->get_policy) |
| 860 | pol = vma->vm_ops->get_policy(vma, addr); |
| 861 | else |
| 862 | pol = vma->vm_policy; |
| 863 | } else if (addr) |
| 864 | return -EINVAL; |
| 865 | |
| 866 | if (!pol) |
| 867 | pol = &default_policy; /* indicates default behavior */ |
| 868 | |
| 869 | if (flags & MPOL_F_NODE) { |
| 870 | if (flags & MPOL_F_ADDR) { |
| 871 | err = lookup_node(mm, addr); |
| 872 | if (err < 0) |
| 873 | goto out; |
| 874 | *policy = err; |
| 875 | } else if (pol == current->mempolicy && |
| 876 | pol->mode == MPOL_INTERLEAVE) { |
| 877 | *policy = current->il_next; |
| 878 | } else { |
| 879 | err = -EINVAL; |
| 880 | goto out; |
| 881 | } |
| 882 | } else { |
| 883 | *policy = pol == &default_policy ? MPOL_DEFAULT : |
| 884 | pol->mode; |
| 885 | /* |
| 886 | * Internal mempolicy flags must be masked off before exposing |
| 887 | * the policy to userspace. |
| 888 | */ |
| 889 | *policy |= (pol->flags & MPOL_MODE_FLAGS); |
| 890 | } |
| 891 | |
| 892 | if (vma) { |
| 893 | up_read(¤t->mm->mmap_sem); |
| 894 | vma = NULL; |
| 895 | } |
| 896 | |
| 897 | err = 0; |
| 898 | if (nmask) { |
| 899 | if (mpol_store_user_nodemask(pol)) { |
| 900 | *nmask = pol->w.user_nodemask; |
| 901 | } else { |
| 902 | task_lock(current); |
| 903 | get_policy_nodemask(pol, nmask); |
| 904 | task_unlock(current); |
| 905 | } |
| 906 | } |
| 907 | |
| 908 | out: |
| 909 | mpol_cond_put(pol); |
| 910 | if (vma) |
| 911 | up_read(¤t->mm->mmap_sem); |
| 912 | return err; |
| 913 | } |
| 914 | |
| 915 | #ifdef CONFIG_MIGRATION |
| 916 | /* |
| 917 | * page migration |
| 918 | */ |
| 919 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 920 | unsigned long flags) |
| 921 | { |
| 922 | /* |
| 923 | * Avoid migrating a page that is shared with others. |
| 924 | */ |
| 925 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { |
| 926 | if (!isolate_lru_page(page)) { |
| 927 | list_add_tail(&page->lru, pagelist); |
| 928 | inc_zone_page_state(page, NR_ISOLATED_ANON + |
| 929 | page_is_file_cache(page)); |
| 930 | } |
| 931 | } |
| 932 | } |
| 933 | |
| 934 | static struct page *new_node_page(struct page *page, unsigned long node, int **x) |
| 935 | { |
| 936 | return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0); |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * Migrate pages from one node to a target node. |
| 941 | * Returns error or the number of pages not migrated. |
| 942 | */ |
| 943 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, |
| 944 | int flags) |
| 945 | { |
| 946 | nodemask_t nmask; |
| 947 | LIST_HEAD(pagelist); |
| 948 | int err = 0; |
| 949 | |
| 950 | nodes_clear(nmask); |
| 951 | node_set(source, nmask); |
| 952 | |
| 953 | /* |
| 954 | * This does not "check" the range but isolates all pages that |
| 955 | * need migration. Between passing in the full user address |
| 956 | * space range and MPOL_MF_DISCONTIG_OK, this call can not fail. |
| 957 | */ |
| 958 | VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); |
| 959 | check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, |
| 960 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); |
| 961 | |
| 962 | if (!list_empty(&pagelist)) { |
| 963 | err = migrate_pages(&pagelist, new_node_page, dest, |
| 964 | false, MIGRATE_SYNC); |
| 965 | if (err) |
| 966 | putback_lru_pages(&pagelist); |
| 967 | } |
| 968 | |
| 969 | return err; |
| 970 | } |
| 971 | |
| 972 | /* |
| 973 | * Move pages between the two nodesets so as to preserve the physical |
| 974 | * layout as much as possible. |
| 975 | * |
| 976 | * Returns the number of page that could not be moved. |
| 977 | */ |
| 978 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 979 | const nodemask_t *to, int flags) |
| 980 | { |
| 981 | int busy = 0; |
| 982 | int err; |
| 983 | nodemask_t tmp; |
| 984 | |
| 985 | err = migrate_prep(); |
| 986 | if (err) |
| 987 | return err; |
| 988 | |
| 989 | down_read(&mm->mmap_sem); |
| 990 | |
| 991 | err = migrate_vmas(mm, from, to, flags); |
| 992 | if (err) |
| 993 | goto out; |
| 994 | |
| 995 | /* |
| 996 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' |
| 997 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' |
| 998 | * bit in 'tmp', and return that <source, dest> pair for migration. |
| 999 | * The pair of nodemasks 'to' and 'from' define the map. |
| 1000 | * |
| 1001 | * If no pair of bits is found that way, fallback to picking some |
| 1002 | * pair of 'source' and 'dest' bits that are not the same. If the |
| 1003 | * 'source' and 'dest' bits are the same, this represents a node |
| 1004 | * that will be migrating to itself, so no pages need move. |
| 1005 | * |
| 1006 | * If no bits are left in 'tmp', or if all remaining bits left |
| 1007 | * in 'tmp' correspond to the same bit in 'to', return false |
| 1008 | * (nothing left to migrate). |
| 1009 | * |
| 1010 | * This lets us pick a pair of nodes to migrate between, such that |
| 1011 | * if possible the dest node is not already occupied by some other |
| 1012 | * source node, minimizing the risk of overloading the memory on a |
| 1013 | * node that would happen if we migrated incoming memory to a node |
| 1014 | * before migrating outgoing memory source that same node. |
| 1015 | * |
| 1016 | * A single scan of tmp is sufficient. As we go, we remember the |
| 1017 | * most recent <s, d> pair that moved (s != d). If we find a pair |
| 1018 | * that not only moved, but what's better, moved to an empty slot |
| 1019 | * (d is not set in tmp), then we break out then, with that pair. |
| 1020 | * Otherwise when we finish scanning from_tmp, we at least have the |
| 1021 | * most recent <s, d> pair that moved. If we get all the way through |
| 1022 | * the scan of tmp without finding any node that moved, much less |
| 1023 | * moved to an empty node, then there is nothing left worth migrating. |
| 1024 | */ |
| 1025 | |
| 1026 | tmp = *from; |
| 1027 | while (!nodes_empty(tmp)) { |
| 1028 | int s,d; |
| 1029 | int source = -1; |
| 1030 | int dest = 0; |
| 1031 | |
| 1032 | for_each_node_mask(s, tmp) { |
| 1033 | |
| 1034 | /* |
| 1035 | * do_migrate_pages() tries to maintain the relative |
| 1036 | * node relationship of the pages established between |
| 1037 | * threads and memory areas. |
| 1038 | * |
| 1039 | * However if the number of source nodes is not equal to |
| 1040 | * the number of destination nodes we can not preserve |
| 1041 | * this node relative relationship. In that case, skip |
| 1042 | * copying memory from a node that is in the destination |
| 1043 | * mask. |
| 1044 | * |
| 1045 | * Example: [2,3,4] -> [3,4,5] moves everything. |
| 1046 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. |
| 1047 | */ |
| 1048 | |
| 1049 | if ((nodes_weight(*from) != nodes_weight(*to)) && |
| 1050 | (node_isset(s, *to))) |
| 1051 | continue; |
| 1052 | |
| 1053 | d = node_remap(s, *from, *to); |
| 1054 | if (s == d) |
| 1055 | continue; |
| 1056 | |
| 1057 | source = s; /* Node moved. Memorize */ |
| 1058 | dest = d; |
| 1059 | |
| 1060 | /* dest not in remaining from nodes? */ |
| 1061 | if (!node_isset(dest, tmp)) |
| 1062 | break; |
| 1063 | } |
| 1064 | if (source == -1) |
| 1065 | break; |
| 1066 | |
| 1067 | node_clear(source, tmp); |
| 1068 | err = migrate_to_node(mm, source, dest, flags); |
| 1069 | if (err > 0) |
| 1070 | busy += err; |
| 1071 | if (err < 0) |
| 1072 | break; |
| 1073 | } |
| 1074 | out: |
| 1075 | up_read(&mm->mmap_sem); |
| 1076 | if (err < 0) |
| 1077 | return err; |
| 1078 | return busy; |
| 1079 | |
| 1080 | } |
| 1081 | |
| 1082 | /* |
| 1083 | * Allocate a new page for page migration based on vma policy. |
| 1084 | * Start assuming that page is mapped by vma pointed to by @private. |
| 1085 | * Search forward from there, if not. N.B., this assumes that the |
| 1086 | * list of pages handed to migrate_pages()--which is how we get here-- |
| 1087 | * is in virtual address order. |
| 1088 | */ |
| 1089 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) |
| 1090 | { |
| 1091 | struct vm_area_struct *vma = (struct vm_area_struct *)private; |
| 1092 | unsigned long uninitialized_var(address); |
| 1093 | |
| 1094 | while (vma) { |
| 1095 | address = page_address_in_vma(page, vma); |
| 1096 | if (address != -EFAULT) |
| 1097 | break; |
| 1098 | vma = vma->vm_next; |
| 1099 | } |
| 1100 | |
| 1101 | /* |
| 1102 | * if !vma, alloc_page_vma() will use task or system default policy |
| 1103 | */ |
| 1104 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); |
| 1105 | } |
| 1106 | #else |
| 1107 | |
| 1108 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 1109 | unsigned long flags) |
| 1110 | { |
| 1111 | } |
| 1112 | |
| 1113 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 1114 | const nodemask_t *to, int flags) |
| 1115 | { |
| 1116 | return -ENOSYS; |
| 1117 | } |
| 1118 | |
| 1119 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) |
| 1120 | { |
| 1121 | return NULL; |
| 1122 | } |
| 1123 | #endif |
| 1124 | |
| 1125 | static long do_mbind(unsigned long start, unsigned long len, |
| 1126 | unsigned short mode, unsigned short mode_flags, |
| 1127 | nodemask_t *nmask, unsigned long flags) |
| 1128 | { |
| 1129 | struct vm_area_struct *vma; |
| 1130 | struct mm_struct *mm = current->mm; |
| 1131 | struct mempolicy *new; |
| 1132 | unsigned long end; |
| 1133 | int err; |
| 1134 | LIST_HEAD(pagelist); |
| 1135 | |
| 1136 | if (flags & ~(unsigned long)(MPOL_MF_STRICT | |
| 1137 | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 1138 | return -EINVAL; |
| 1139 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) |
| 1140 | return -EPERM; |
| 1141 | |
| 1142 | if (start & ~PAGE_MASK) |
| 1143 | return -EINVAL; |
| 1144 | |
| 1145 | if (mode == MPOL_DEFAULT) |
| 1146 | flags &= ~MPOL_MF_STRICT; |
| 1147 | |
| 1148 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; |
| 1149 | end = start + len; |
| 1150 | |
| 1151 | if (end < start) |
| 1152 | return -EINVAL; |
| 1153 | if (end == start) |
| 1154 | return 0; |
| 1155 | |
| 1156 | new = mpol_new(mode, mode_flags, nmask); |
| 1157 | if (IS_ERR(new)) |
| 1158 | return PTR_ERR(new); |
| 1159 | |
| 1160 | /* |
| 1161 | * If we are using the default policy then operation |
| 1162 | * on discontinuous address spaces is okay after all |
| 1163 | */ |
| 1164 | if (!new) |
| 1165 | flags |= MPOL_MF_DISCONTIG_OK; |
| 1166 | |
| 1167 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", |
| 1168 | start, start + len, mode, mode_flags, |
| 1169 | nmask ? nodes_addr(*nmask)[0] : -1); |
| 1170 | |
| 1171 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { |
| 1172 | |
| 1173 | err = migrate_prep(); |
| 1174 | if (err) |
| 1175 | goto mpol_out; |
| 1176 | } |
| 1177 | { |
| 1178 | NODEMASK_SCRATCH(scratch); |
| 1179 | if (scratch) { |
| 1180 | down_write(&mm->mmap_sem); |
| 1181 | task_lock(current); |
| 1182 | err = mpol_set_nodemask(new, nmask, scratch); |
| 1183 | task_unlock(current); |
| 1184 | if (err) |
| 1185 | up_write(&mm->mmap_sem); |
| 1186 | } else |
| 1187 | err = -ENOMEM; |
| 1188 | NODEMASK_SCRATCH_FREE(scratch); |
| 1189 | } |
| 1190 | if (err) |
| 1191 | goto mpol_out; |
| 1192 | |
| 1193 | vma = check_range(mm, start, end, nmask, |
| 1194 | flags | MPOL_MF_INVERT, &pagelist); |
| 1195 | |
| 1196 | err = PTR_ERR(vma); |
| 1197 | if (!IS_ERR(vma)) { |
| 1198 | int nr_failed = 0; |
| 1199 | |
| 1200 | err = mbind_range(mm, start, end, new); |
| 1201 | |
| 1202 | if (!list_empty(&pagelist)) { |
| 1203 | nr_failed = migrate_pages(&pagelist, new_vma_page, |
| 1204 | (unsigned long)vma, |
| 1205 | false, MIGRATE_SYNC); |
| 1206 | if (nr_failed) |
| 1207 | putback_lru_pages(&pagelist); |
| 1208 | } |
| 1209 | |
| 1210 | if (!err && nr_failed && (flags & MPOL_MF_STRICT)) |
| 1211 | err = -EIO; |
| 1212 | } else |
| 1213 | putback_lru_pages(&pagelist); |
| 1214 | |
| 1215 | up_write(&mm->mmap_sem); |
| 1216 | mpol_out: |
| 1217 | mpol_put(new); |
| 1218 | return err; |
| 1219 | } |
| 1220 | |
| 1221 | /* |
| 1222 | * User space interface with variable sized bitmaps for nodelists. |
| 1223 | */ |
| 1224 | |
| 1225 | /* Copy a node mask from user space. */ |
| 1226 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, |
| 1227 | unsigned long maxnode) |
| 1228 | { |
| 1229 | unsigned long k; |
| 1230 | unsigned long nlongs; |
| 1231 | unsigned long endmask; |
| 1232 | |
| 1233 | --maxnode; |
| 1234 | nodes_clear(*nodes); |
| 1235 | if (maxnode == 0 || !nmask) |
| 1236 | return 0; |
| 1237 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) |
| 1238 | return -EINVAL; |
| 1239 | |
| 1240 | nlongs = BITS_TO_LONGS(maxnode); |
| 1241 | if ((maxnode % BITS_PER_LONG) == 0) |
| 1242 | endmask = ~0UL; |
| 1243 | else |
| 1244 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; |
| 1245 | |
| 1246 | /* When the user specified more nodes than supported just check |
| 1247 | if the non supported part is all zero. */ |
| 1248 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { |
| 1249 | if (nlongs > PAGE_SIZE/sizeof(long)) |
| 1250 | return -EINVAL; |
| 1251 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { |
| 1252 | unsigned long t; |
| 1253 | if (get_user(t, nmask + k)) |
| 1254 | return -EFAULT; |
| 1255 | if (k == nlongs - 1) { |
| 1256 | if (t & endmask) |
| 1257 | return -EINVAL; |
| 1258 | } else if (t) |
| 1259 | return -EINVAL; |
| 1260 | } |
| 1261 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); |
| 1262 | endmask = ~0UL; |
| 1263 | } |
| 1264 | |
| 1265 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) |
| 1266 | return -EFAULT; |
| 1267 | nodes_addr(*nodes)[nlongs-1] &= endmask; |
| 1268 | return 0; |
| 1269 | } |
| 1270 | |
| 1271 | /* Copy a kernel node mask to user space */ |
| 1272 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, |
| 1273 | nodemask_t *nodes) |
| 1274 | { |
| 1275 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; |
| 1276 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); |
| 1277 | |
| 1278 | if (copy > nbytes) { |
| 1279 | if (copy > PAGE_SIZE) |
| 1280 | return -EINVAL; |
| 1281 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) |
| 1282 | return -EFAULT; |
| 1283 | copy = nbytes; |
| 1284 | } |
| 1285 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; |
| 1286 | } |
| 1287 | |
| 1288 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, |
| 1289 | unsigned long, mode, unsigned long __user *, nmask, |
| 1290 | unsigned long, maxnode, unsigned, flags) |
| 1291 | { |
| 1292 | nodemask_t nodes; |
| 1293 | int err; |
| 1294 | unsigned short mode_flags; |
| 1295 | |
| 1296 | mode_flags = mode & MPOL_MODE_FLAGS; |
| 1297 | mode &= ~MPOL_MODE_FLAGS; |
| 1298 | if (mode >= MPOL_MAX) |
| 1299 | return -EINVAL; |
| 1300 | if ((mode_flags & MPOL_F_STATIC_NODES) && |
| 1301 | (mode_flags & MPOL_F_RELATIVE_NODES)) |
| 1302 | return -EINVAL; |
| 1303 | err = get_nodes(&nodes, nmask, maxnode); |
| 1304 | if (err) |
| 1305 | return err; |
| 1306 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); |
| 1307 | } |
| 1308 | |
| 1309 | /* Set the process memory policy */ |
| 1310 | SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask, |
| 1311 | unsigned long, maxnode) |
| 1312 | { |
| 1313 | int err; |
| 1314 | nodemask_t nodes; |
| 1315 | unsigned short flags; |
| 1316 | |
| 1317 | flags = mode & MPOL_MODE_FLAGS; |
| 1318 | mode &= ~MPOL_MODE_FLAGS; |
| 1319 | if ((unsigned int)mode >= MPOL_MAX) |
| 1320 | return -EINVAL; |
| 1321 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) |
| 1322 | return -EINVAL; |
| 1323 | err = get_nodes(&nodes, nmask, maxnode); |
| 1324 | if (err) |
| 1325 | return err; |
| 1326 | return do_set_mempolicy(mode, flags, &nodes); |
| 1327 | } |
| 1328 | |
| 1329 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, |
| 1330 | const unsigned long __user *, old_nodes, |
| 1331 | const unsigned long __user *, new_nodes) |
| 1332 | { |
| 1333 | const struct cred *cred = current_cred(), *tcred; |
| 1334 | struct mm_struct *mm = NULL; |
| 1335 | struct task_struct *task; |
| 1336 | nodemask_t task_nodes; |
| 1337 | int err; |
| 1338 | nodemask_t *old; |
| 1339 | nodemask_t *new; |
| 1340 | NODEMASK_SCRATCH(scratch); |
| 1341 | |
| 1342 | if (!scratch) |
| 1343 | return -ENOMEM; |
| 1344 | |
| 1345 | old = &scratch->mask1; |
| 1346 | new = &scratch->mask2; |
| 1347 | |
| 1348 | err = get_nodes(old, old_nodes, maxnode); |
| 1349 | if (err) |
| 1350 | goto out; |
| 1351 | |
| 1352 | err = get_nodes(new, new_nodes, maxnode); |
| 1353 | if (err) |
| 1354 | goto out; |
| 1355 | |
| 1356 | /* Find the mm_struct */ |
| 1357 | rcu_read_lock(); |
| 1358 | task = pid ? find_task_by_vpid(pid) : current; |
| 1359 | if (!task) { |
| 1360 | rcu_read_unlock(); |
| 1361 | err = -ESRCH; |
| 1362 | goto out; |
| 1363 | } |
| 1364 | get_task_struct(task); |
| 1365 | |
| 1366 | err = -EINVAL; |
| 1367 | |
| 1368 | /* |
| 1369 | * Check if this process has the right to modify the specified |
| 1370 | * process. The right exists if the process has administrative |
| 1371 | * capabilities, superuser privileges or the same |
| 1372 | * userid as the target process. |
| 1373 | */ |
| 1374 | tcred = __task_cred(task); |
| 1375 | if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) && |
| 1376 | !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) && |
| 1377 | !capable(CAP_SYS_NICE)) { |
| 1378 | rcu_read_unlock(); |
| 1379 | err = -EPERM; |
| 1380 | goto out_put; |
| 1381 | } |
| 1382 | rcu_read_unlock(); |
| 1383 | |
| 1384 | task_nodes = cpuset_mems_allowed(task); |
| 1385 | /* Is the user allowed to access the target nodes? */ |
| 1386 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { |
| 1387 | err = -EPERM; |
| 1388 | goto out_put; |
| 1389 | } |
| 1390 | |
| 1391 | if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) { |
| 1392 | err = -EINVAL; |
| 1393 | goto out_put; |
| 1394 | } |
| 1395 | |
| 1396 | err = security_task_movememory(task); |
| 1397 | if (err) |
| 1398 | goto out_put; |
| 1399 | |
| 1400 | mm = get_task_mm(task); |
| 1401 | put_task_struct(task); |
| 1402 | |
| 1403 | if (!mm) { |
| 1404 | err = -EINVAL; |
| 1405 | goto out; |
| 1406 | } |
| 1407 | |
| 1408 | err = do_migrate_pages(mm, old, new, |
| 1409 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); |
| 1410 | |
| 1411 | mmput(mm); |
| 1412 | out: |
| 1413 | NODEMASK_SCRATCH_FREE(scratch); |
| 1414 | |
| 1415 | return err; |
| 1416 | |
| 1417 | out_put: |
| 1418 | put_task_struct(task); |
| 1419 | goto out; |
| 1420 | |
| 1421 | } |
| 1422 | |
| 1423 | |
| 1424 | /* Retrieve NUMA policy */ |
| 1425 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
| 1426 | unsigned long __user *, nmask, unsigned long, maxnode, |
| 1427 | unsigned long, addr, unsigned long, flags) |
| 1428 | { |
| 1429 | int err; |
| 1430 | int uninitialized_var(pval); |
| 1431 | nodemask_t nodes; |
| 1432 | |
| 1433 | if (nmask != NULL && maxnode < MAX_NUMNODES) |
| 1434 | return -EINVAL; |
| 1435 | |
| 1436 | err = do_get_mempolicy(&pval, &nodes, addr, flags); |
| 1437 | |
| 1438 | if (err) |
| 1439 | return err; |
| 1440 | |
| 1441 | if (policy && put_user(pval, policy)) |
| 1442 | return -EFAULT; |
| 1443 | |
| 1444 | if (nmask) |
| 1445 | err = copy_nodes_to_user(nmask, maxnode, &nodes); |
| 1446 | |
| 1447 | return err; |
| 1448 | } |
| 1449 | |
| 1450 | #ifdef CONFIG_COMPAT |
| 1451 | |
| 1452 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, |
| 1453 | compat_ulong_t __user *nmask, |
| 1454 | compat_ulong_t maxnode, |
| 1455 | compat_ulong_t addr, compat_ulong_t flags) |
| 1456 | { |
| 1457 | long err; |
| 1458 | unsigned long __user *nm = NULL; |
| 1459 | unsigned long nr_bits, alloc_size; |
| 1460 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
| 1461 | |
| 1462 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1463 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1464 | |
| 1465 | if (nmask) |
| 1466 | nm = compat_alloc_user_space(alloc_size); |
| 1467 | |
| 1468 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); |
| 1469 | |
| 1470 | if (!err && nmask) { |
| 1471 | unsigned long copy_size; |
| 1472 | copy_size = min_t(unsigned long, sizeof(bm), alloc_size); |
| 1473 | err = copy_from_user(bm, nm, copy_size); |
| 1474 | /* ensure entire bitmap is zeroed */ |
| 1475 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); |
| 1476 | err |= compat_put_bitmap(nmask, bm, nr_bits); |
| 1477 | } |
| 1478 | |
| 1479 | return err; |
| 1480 | } |
| 1481 | |
| 1482 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, |
| 1483 | compat_ulong_t maxnode) |
| 1484 | { |
| 1485 | long err = 0; |
| 1486 | unsigned long __user *nm = NULL; |
| 1487 | unsigned long nr_bits, alloc_size; |
| 1488 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
| 1489 | |
| 1490 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1491 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1492 | |
| 1493 | if (nmask) { |
| 1494 | err = compat_get_bitmap(bm, nmask, nr_bits); |
| 1495 | nm = compat_alloc_user_space(alloc_size); |
| 1496 | err |= copy_to_user(nm, bm, alloc_size); |
| 1497 | } |
| 1498 | |
| 1499 | if (err) |
| 1500 | return -EFAULT; |
| 1501 | |
| 1502 | return sys_set_mempolicy(mode, nm, nr_bits+1); |
| 1503 | } |
| 1504 | |
| 1505 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, |
| 1506 | compat_ulong_t mode, compat_ulong_t __user *nmask, |
| 1507 | compat_ulong_t maxnode, compat_ulong_t flags) |
| 1508 | { |
| 1509 | long err = 0; |
| 1510 | unsigned long __user *nm = NULL; |
| 1511 | unsigned long nr_bits, alloc_size; |
| 1512 | nodemask_t bm; |
| 1513 | |
| 1514 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1515 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1516 | |
| 1517 | if (nmask) { |
| 1518 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); |
| 1519 | nm = compat_alloc_user_space(alloc_size); |
| 1520 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); |
| 1521 | } |
| 1522 | |
| 1523 | if (err) |
| 1524 | return -EFAULT; |
| 1525 | |
| 1526 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); |
| 1527 | } |
| 1528 | |
| 1529 | #endif |
| 1530 | |
| 1531 | /* |
| 1532 | * get_vma_policy(@task, @vma, @addr) |
| 1533 | * @task - task for fallback if vma policy == default |
| 1534 | * @vma - virtual memory area whose policy is sought |
| 1535 | * @addr - address in @vma for shared policy lookup |
| 1536 | * |
| 1537 | * Returns effective policy for a VMA at specified address. |
| 1538 | * Falls back to @task or system default policy, as necessary. |
| 1539 | * Current or other task's task mempolicy and non-shared vma policies |
| 1540 | * are protected by the task's mmap_sem, which must be held for read by |
| 1541 | * the caller. |
| 1542 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference |
| 1543 | * count--added by the get_policy() vm_op, as appropriate--to protect against |
| 1544 | * freeing by another task. It is the caller's responsibility to free the |
| 1545 | * extra reference for shared policies. |
| 1546 | */ |
| 1547 | struct mempolicy *get_vma_policy(struct task_struct *task, |
| 1548 | struct vm_area_struct *vma, unsigned long addr) |
| 1549 | { |
| 1550 | struct mempolicy *pol = task->mempolicy; |
| 1551 | |
| 1552 | if (vma) { |
| 1553 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
| 1554 | struct mempolicy *vpol = vma->vm_ops->get_policy(vma, |
| 1555 | addr); |
| 1556 | if (vpol) |
| 1557 | pol = vpol; |
| 1558 | } else if (vma->vm_policy) { |
| 1559 | pol = vma->vm_policy; |
| 1560 | |
| 1561 | /* |
| 1562 | * shmem_alloc_page() passes MPOL_F_SHARED policy with |
| 1563 | * a pseudo vma whose vma->vm_ops=NULL. Take a reference |
| 1564 | * count on these policies which will be dropped by |
| 1565 | * mpol_cond_put() later |
| 1566 | */ |
| 1567 | if (mpol_needs_cond_ref(pol)) |
| 1568 | mpol_get(pol); |
| 1569 | } |
| 1570 | } |
| 1571 | if (!pol) |
| 1572 | pol = &default_policy; |
| 1573 | return pol; |
| 1574 | } |
| 1575 | |
| 1576 | /* |
| 1577 | * Return a nodemask representing a mempolicy for filtering nodes for |
| 1578 | * page allocation |
| 1579 | */ |
| 1580 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) |
| 1581 | { |
| 1582 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ |
| 1583 | if (unlikely(policy->mode == MPOL_BIND) && |
| 1584 | gfp_zone(gfp) >= policy_zone && |
| 1585 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) |
| 1586 | return &policy->v.nodes; |
| 1587 | |
| 1588 | return NULL; |
| 1589 | } |
| 1590 | |
| 1591 | /* Return a zonelist indicated by gfp for node representing a mempolicy */ |
| 1592 | static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy, |
| 1593 | int nd) |
| 1594 | { |
| 1595 | switch (policy->mode) { |
| 1596 | case MPOL_PREFERRED: |
| 1597 | if (!(policy->flags & MPOL_F_LOCAL)) |
| 1598 | nd = policy->v.preferred_node; |
| 1599 | break; |
| 1600 | case MPOL_BIND: |
| 1601 | /* |
| 1602 | * Normally, MPOL_BIND allocations are node-local within the |
| 1603 | * allowed nodemask. However, if __GFP_THISNODE is set and the |
| 1604 | * current node isn't part of the mask, we use the zonelist for |
| 1605 | * the first node in the mask instead. |
| 1606 | */ |
| 1607 | if (unlikely(gfp & __GFP_THISNODE) && |
| 1608 | unlikely(!node_isset(nd, policy->v.nodes))) |
| 1609 | nd = first_node(policy->v.nodes); |
| 1610 | break; |
| 1611 | default: |
| 1612 | BUG(); |
| 1613 | } |
| 1614 | return node_zonelist(nd, gfp); |
| 1615 | } |
| 1616 | |
| 1617 | /* Do dynamic interleaving for a process */ |
| 1618 | static unsigned interleave_nodes(struct mempolicy *policy) |
| 1619 | { |
| 1620 | unsigned nid, next; |
| 1621 | struct task_struct *me = current; |
| 1622 | |
| 1623 | nid = me->il_next; |
| 1624 | next = next_node(nid, policy->v.nodes); |
| 1625 | if (next >= MAX_NUMNODES) |
| 1626 | next = first_node(policy->v.nodes); |
| 1627 | if (next < MAX_NUMNODES) |
| 1628 | me->il_next = next; |
| 1629 | return nid; |
| 1630 | } |
| 1631 | |
| 1632 | /* |
| 1633 | * Depending on the memory policy provide a node from which to allocate the |
| 1634 | * next slab entry. |
| 1635 | * @policy must be protected by freeing by the caller. If @policy is |
| 1636 | * the current task's mempolicy, this protection is implicit, as only the |
| 1637 | * task can change it's policy. The system default policy requires no |
| 1638 | * such protection. |
| 1639 | */ |
| 1640 | unsigned slab_node(void) |
| 1641 | { |
| 1642 | struct mempolicy *policy; |
| 1643 | |
| 1644 | if (in_interrupt()) |
| 1645 | return numa_node_id(); |
| 1646 | |
| 1647 | policy = current->mempolicy; |
| 1648 | if (!policy || policy->flags & MPOL_F_LOCAL) |
| 1649 | return numa_node_id(); |
| 1650 | |
| 1651 | switch (policy->mode) { |
| 1652 | case MPOL_PREFERRED: |
| 1653 | /* |
| 1654 | * handled MPOL_F_LOCAL above |
| 1655 | */ |
| 1656 | return policy->v.preferred_node; |
| 1657 | |
| 1658 | case MPOL_INTERLEAVE: |
| 1659 | return interleave_nodes(policy); |
| 1660 | |
| 1661 | case MPOL_BIND: { |
| 1662 | /* |
| 1663 | * Follow bind policy behavior and start allocation at the |
| 1664 | * first node. |
| 1665 | */ |
| 1666 | struct zonelist *zonelist; |
| 1667 | struct zone *zone; |
| 1668 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); |
| 1669 | zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0]; |
| 1670 | (void)first_zones_zonelist(zonelist, highest_zoneidx, |
| 1671 | &policy->v.nodes, |
| 1672 | &zone); |
| 1673 | return zone ? zone->node : numa_node_id(); |
| 1674 | } |
| 1675 | |
| 1676 | default: |
| 1677 | BUG(); |
| 1678 | } |
| 1679 | } |
| 1680 | |
| 1681 | /* Do static interleaving for a VMA with known offset. */ |
| 1682 | static unsigned offset_il_node(struct mempolicy *pol, |
| 1683 | struct vm_area_struct *vma, unsigned long off) |
| 1684 | { |
| 1685 | unsigned nnodes = nodes_weight(pol->v.nodes); |
| 1686 | unsigned target; |
| 1687 | int c; |
| 1688 | int nid = -1; |
| 1689 | |
| 1690 | if (!nnodes) |
| 1691 | return numa_node_id(); |
| 1692 | target = (unsigned int)off % nnodes; |
| 1693 | c = 0; |
| 1694 | do { |
| 1695 | nid = next_node(nid, pol->v.nodes); |
| 1696 | c++; |
| 1697 | } while (c <= target); |
| 1698 | return nid; |
| 1699 | } |
| 1700 | |
| 1701 | /* Determine a node number for interleave */ |
| 1702 | static inline unsigned interleave_nid(struct mempolicy *pol, |
| 1703 | struct vm_area_struct *vma, unsigned long addr, int shift) |
| 1704 | { |
| 1705 | if (vma) { |
| 1706 | unsigned long off; |
| 1707 | |
| 1708 | /* |
| 1709 | * for small pages, there is no difference between |
| 1710 | * shift and PAGE_SHIFT, so the bit-shift is safe. |
| 1711 | * for huge pages, since vm_pgoff is in units of small |
| 1712 | * pages, we need to shift off the always 0 bits to get |
| 1713 | * a useful offset. |
| 1714 | */ |
| 1715 | BUG_ON(shift < PAGE_SHIFT); |
| 1716 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); |
| 1717 | off += (addr - vma->vm_start) >> shift; |
| 1718 | return offset_il_node(pol, vma, off); |
| 1719 | } else |
| 1720 | return interleave_nodes(pol); |
| 1721 | } |
| 1722 | |
| 1723 | /* |
| 1724 | * Return the bit number of a random bit set in the nodemask. |
| 1725 | * (returns -1 if nodemask is empty) |
| 1726 | */ |
| 1727 | int node_random(const nodemask_t *maskp) |
| 1728 | { |
| 1729 | int w, bit = -1; |
| 1730 | |
| 1731 | w = nodes_weight(*maskp); |
| 1732 | if (w) |
| 1733 | bit = bitmap_ord_to_pos(maskp->bits, |
| 1734 | get_random_int() % w, MAX_NUMNODES); |
| 1735 | return bit; |
| 1736 | } |
| 1737 | |
| 1738 | #ifdef CONFIG_HUGETLBFS |
| 1739 | /* |
| 1740 | * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) |
| 1741 | * @vma = virtual memory area whose policy is sought |
| 1742 | * @addr = address in @vma for shared policy lookup and interleave policy |
| 1743 | * @gfp_flags = for requested zone |
| 1744 | * @mpol = pointer to mempolicy pointer for reference counted mempolicy |
| 1745 | * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask |
| 1746 | * |
| 1747 | * Returns a zonelist suitable for a huge page allocation and a pointer |
| 1748 | * to the struct mempolicy for conditional unref after allocation. |
| 1749 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's |
| 1750 | * @nodemask for filtering the zonelist. |
| 1751 | * |
| 1752 | * Must be protected by get_mems_allowed() |
| 1753 | */ |
| 1754 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, |
| 1755 | gfp_t gfp_flags, struct mempolicy **mpol, |
| 1756 | nodemask_t **nodemask) |
| 1757 | { |
| 1758 | struct zonelist *zl; |
| 1759 | |
| 1760 | *mpol = get_vma_policy(current, vma, addr); |
| 1761 | *nodemask = NULL; /* assume !MPOL_BIND */ |
| 1762 | |
| 1763 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { |
| 1764 | zl = node_zonelist(interleave_nid(*mpol, vma, addr, |
| 1765 | huge_page_shift(hstate_vma(vma))), gfp_flags); |
| 1766 | } else { |
| 1767 | zl = policy_zonelist(gfp_flags, *mpol, numa_node_id()); |
| 1768 | if ((*mpol)->mode == MPOL_BIND) |
| 1769 | *nodemask = &(*mpol)->v.nodes; |
| 1770 | } |
| 1771 | return zl; |
| 1772 | } |
| 1773 | |
| 1774 | /* |
| 1775 | * init_nodemask_of_mempolicy |
| 1776 | * |
| 1777 | * If the current task's mempolicy is "default" [NULL], return 'false' |
| 1778 | * to indicate default policy. Otherwise, extract the policy nodemask |
| 1779 | * for 'bind' or 'interleave' policy into the argument nodemask, or |
| 1780 | * initialize the argument nodemask to contain the single node for |
| 1781 | * 'preferred' or 'local' policy and return 'true' to indicate presence |
| 1782 | * of non-default mempolicy. |
| 1783 | * |
| 1784 | * We don't bother with reference counting the mempolicy [mpol_get/put] |
| 1785 | * because the current task is examining it's own mempolicy and a task's |
| 1786 | * mempolicy is only ever changed by the task itself. |
| 1787 | * |
| 1788 | * N.B., it is the caller's responsibility to free a returned nodemask. |
| 1789 | */ |
| 1790 | bool init_nodemask_of_mempolicy(nodemask_t *mask) |
| 1791 | { |
| 1792 | struct mempolicy *mempolicy; |
| 1793 | int nid; |
| 1794 | |
| 1795 | if (!(mask && current->mempolicy)) |
| 1796 | return false; |
| 1797 | |
| 1798 | task_lock(current); |
| 1799 | mempolicy = current->mempolicy; |
| 1800 | switch (mempolicy->mode) { |
| 1801 | case MPOL_PREFERRED: |
| 1802 | if (mempolicy->flags & MPOL_F_LOCAL) |
| 1803 | nid = numa_node_id(); |
| 1804 | else |
| 1805 | nid = mempolicy->v.preferred_node; |
| 1806 | init_nodemask_of_node(mask, nid); |
| 1807 | break; |
| 1808 | |
| 1809 | case MPOL_BIND: |
| 1810 | /* Fall through */ |
| 1811 | case MPOL_INTERLEAVE: |
| 1812 | *mask = mempolicy->v.nodes; |
| 1813 | break; |
| 1814 | |
| 1815 | default: |
| 1816 | BUG(); |
| 1817 | } |
| 1818 | task_unlock(current); |
| 1819 | |
| 1820 | return true; |
| 1821 | } |
| 1822 | #endif |
| 1823 | |
| 1824 | /* |
| 1825 | * mempolicy_nodemask_intersects |
| 1826 | * |
| 1827 | * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default |
| 1828 | * policy. Otherwise, check for intersection between mask and the policy |
| 1829 | * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' |
| 1830 | * policy, always return true since it may allocate elsewhere on fallback. |
| 1831 | * |
| 1832 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. |
| 1833 | */ |
| 1834 | bool mempolicy_nodemask_intersects(struct task_struct *tsk, |
| 1835 | const nodemask_t *mask) |
| 1836 | { |
| 1837 | struct mempolicy *mempolicy; |
| 1838 | bool ret = true; |
| 1839 | |
| 1840 | if (!mask) |
| 1841 | return ret; |
| 1842 | task_lock(tsk); |
| 1843 | mempolicy = tsk->mempolicy; |
| 1844 | if (!mempolicy) |
| 1845 | goto out; |
| 1846 | |
| 1847 | switch (mempolicy->mode) { |
| 1848 | case MPOL_PREFERRED: |
| 1849 | /* |
| 1850 | * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to |
| 1851 | * allocate from, they may fallback to other nodes when oom. |
| 1852 | * Thus, it's possible for tsk to have allocated memory from |
| 1853 | * nodes in mask. |
| 1854 | */ |
| 1855 | break; |
| 1856 | case MPOL_BIND: |
| 1857 | case MPOL_INTERLEAVE: |
| 1858 | ret = nodes_intersects(mempolicy->v.nodes, *mask); |
| 1859 | break; |
| 1860 | default: |
| 1861 | BUG(); |
| 1862 | } |
| 1863 | out: |
| 1864 | task_unlock(tsk); |
| 1865 | return ret; |
| 1866 | } |
| 1867 | |
| 1868 | /* Allocate a page in interleaved policy. |
| 1869 | Own path because it needs to do special accounting. */ |
| 1870 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, |
| 1871 | unsigned nid) |
| 1872 | { |
| 1873 | struct zonelist *zl; |
| 1874 | struct page *page; |
| 1875 | |
| 1876 | zl = node_zonelist(nid, gfp); |
| 1877 | page = __alloc_pages(gfp, order, zl); |
| 1878 | if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) |
| 1879 | inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); |
| 1880 | return page; |
| 1881 | } |
| 1882 | |
| 1883 | /** |
| 1884 | * alloc_pages_vma - Allocate a page for a VMA. |
| 1885 | * |
| 1886 | * @gfp: |
| 1887 | * %GFP_USER user allocation. |
| 1888 | * %GFP_KERNEL kernel allocations, |
| 1889 | * %GFP_HIGHMEM highmem/user allocations, |
| 1890 | * %GFP_FS allocation should not call back into a file system. |
| 1891 | * %GFP_ATOMIC don't sleep. |
| 1892 | * |
| 1893 | * @order:Order of the GFP allocation. |
| 1894 | * @vma: Pointer to VMA or NULL if not available. |
| 1895 | * @addr: Virtual Address of the allocation. Must be inside the VMA. |
| 1896 | * |
| 1897 | * This function allocates a page from the kernel page pool and applies |
| 1898 | * a NUMA policy associated with the VMA or the current process. |
| 1899 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the |
| 1900 | * mm_struct of the VMA to prevent it from going away. Should be used for |
| 1901 | * all allocations for pages that will be mapped into |
| 1902 | * user space. Returns NULL when no page can be allocated. |
| 1903 | * |
| 1904 | * Should be called with the mm_sem of the vma hold. |
| 1905 | */ |
| 1906 | struct page * |
| 1907 | alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, |
| 1908 | unsigned long addr, int node) |
| 1909 | { |
| 1910 | struct mempolicy *pol; |
| 1911 | struct zonelist *zl; |
| 1912 | struct page *page; |
| 1913 | unsigned int cpuset_mems_cookie; |
| 1914 | |
| 1915 | retry_cpuset: |
| 1916 | pol = get_vma_policy(current, vma, addr); |
| 1917 | cpuset_mems_cookie = get_mems_allowed(); |
| 1918 | |
| 1919 | if (unlikely(pol->mode == MPOL_INTERLEAVE)) { |
| 1920 | unsigned nid; |
| 1921 | |
| 1922 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order); |
| 1923 | mpol_cond_put(pol); |
| 1924 | page = alloc_page_interleave(gfp, order, nid); |
| 1925 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) |
| 1926 | goto retry_cpuset; |
| 1927 | |
| 1928 | return page; |
| 1929 | } |
| 1930 | zl = policy_zonelist(gfp, pol, node); |
| 1931 | if (unlikely(mpol_needs_cond_ref(pol))) { |
| 1932 | /* |
| 1933 | * slow path: ref counted shared policy |
| 1934 | */ |
| 1935 | struct page *page = __alloc_pages_nodemask(gfp, order, |
| 1936 | zl, policy_nodemask(gfp, pol)); |
| 1937 | __mpol_put(pol); |
| 1938 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) |
| 1939 | goto retry_cpuset; |
| 1940 | return page; |
| 1941 | } |
| 1942 | /* |
| 1943 | * fast path: default or task policy |
| 1944 | */ |
| 1945 | page = __alloc_pages_nodemask(gfp, order, zl, |
| 1946 | policy_nodemask(gfp, pol)); |
| 1947 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) |
| 1948 | goto retry_cpuset; |
| 1949 | return page; |
| 1950 | } |
| 1951 | |
| 1952 | /** |
| 1953 | * alloc_pages_current - Allocate pages. |
| 1954 | * |
| 1955 | * @gfp: |
| 1956 | * %GFP_USER user allocation, |
| 1957 | * %GFP_KERNEL kernel allocation, |
| 1958 | * %GFP_HIGHMEM highmem allocation, |
| 1959 | * %GFP_FS don't call back into a file system. |
| 1960 | * %GFP_ATOMIC don't sleep. |
| 1961 | * @order: Power of two of allocation size in pages. 0 is a single page. |
| 1962 | * |
| 1963 | * Allocate a page from the kernel page pool. When not in |
| 1964 | * interrupt context and apply the current process NUMA policy. |
| 1965 | * Returns NULL when no page can be allocated. |
| 1966 | * |
| 1967 | * Don't call cpuset_update_task_memory_state() unless |
| 1968 | * 1) it's ok to take cpuset_sem (can WAIT), and |
| 1969 | * 2) allocating for current task (not interrupt). |
| 1970 | */ |
| 1971 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) |
| 1972 | { |
| 1973 | struct mempolicy *pol = current->mempolicy; |
| 1974 | struct page *page; |
| 1975 | unsigned int cpuset_mems_cookie; |
| 1976 | |
| 1977 | if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) |
| 1978 | pol = &default_policy; |
| 1979 | |
| 1980 | retry_cpuset: |
| 1981 | cpuset_mems_cookie = get_mems_allowed(); |
| 1982 | |
| 1983 | /* |
| 1984 | * No reference counting needed for current->mempolicy |
| 1985 | * nor system default_policy |
| 1986 | */ |
| 1987 | if (pol->mode == MPOL_INTERLEAVE) |
| 1988 | page = alloc_page_interleave(gfp, order, interleave_nodes(pol)); |
| 1989 | else |
| 1990 | page = __alloc_pages_nodemask(gfp, order, |
| 1991 | policy_zonelist(gfp, pol, numa_node_id()), |
| 1992 | policy_nodemask(gfp, pol)); |
| 1993 | |
| 1994 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) |
| 1995 | goto retry_cpuset; |
| 1996 | |
| 1997 | return page; |
| 1998 | } |
| 1999 | EXPORT_SYMBOL(alloc_pages_current); |
| 2000 | |
| 2001 | /* |
| 2002 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it |
| 2003 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() |
| 2004 | * with the mems_allowed returned by cpuset_mems_allowed(). This |
| 2005 | * keeps mempolicies cpuset relative after its cpuset moves. See |
| 2006 | * further kernel/cpuset.c update_nodemask(). |
| 2007 | * |
| 2008 | * current's mempolicy may be rebinded by the other task(the task that changes |
| 2009 | * cpuset's mems), so we needn't do rebind work for current task. |
| 2010 | */ |
| 2011 | |
| 2012 | /* Slow path of a mempolicy duplicate */ |
| 2013 | struct mempolicy *__mpol_dup(struct mempolicy *old) |
| 2014 | { |
| 2015 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 2016 | |
| 2017 | if (!new) |
| 2018 | return ERR_PTR(-ENOMEM); |
| 2019 | |
| 2020 | /* task's mempolicy is protected by alloc_lock */ |
| 2021 | if (old == current->mempolicy) { |
| 2022 | task_lock(current); |
| 2023 | *new = *old; |
| 2024 | task_unlock(current); |
| 2025 | } else |
| 2026 | *new = *old; |
| 2027 | |
| 2028 | rcu_read_lock(); |
| 2029 | if (current_cpuset_is_being_rebound()) { |
| 2030 | nodemask_t mems = cpuset_mems_allowed(current); |
| 2031 | if (new->flags & MPOL_F_REBINDING) |
| 2032 | mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2); |
| 2033 | else |
| 2034 | mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); |
| 2035 | } |
| 2036 | rcu_read_unlock(); |
| 2037 | atomic_set(&new->refcnt, 1); |
| 2038 | return new; |
| 2039 | } |
| 2040 | |
| 2041 | /* |
| 2042 | * If *frompol needs [has] an extra ref, copy *frompol to *tompol , |
| 2043 | * eliminate the * MPOL_F_* flags that require conditional ref and |
| 2044 | * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly |
| 2045 | * after return. Use the returned value. |
| 2046 | * |
| 2047 | * Allows use of a mempolicy for, e.g., multiple allocations with a single |
| 2048 | * policy lookup, even if the policy needs/has extra ref on lookup. |
| 2049 | * shmem_readahead needs this. |
| 2050 | */ |
| 2051 | struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol, |
| 2052 | struct mempolicy *frompol) |
| 2053 | { |
| 2054 | if (!mpol_needs_cond_ref(frompol)) |
| 2055 | return frompol; |
| 2056 | |
| 2057 | *tompol = *frompol; |
| 2058 | tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */ |
| 2059 | __mpol_put(frompol); |
| 2060 | return tompol; |
| 2061 | } |
| 2062 | |
| 2063 | /* Slow path of a mempolicy comparison */ |
| 2064 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) |
| 2065 | { |
| 2066 | if (!a || !b) |
| 2067 | return false; |
| 2068 | if (a->mode != b->mode) |
| 2069 | return false; |
| 2070 | if (a->flags != b->flags) |
| 2071 | return false; |
| 2072 | if (mpol_store_user_nodemask(a)) |
| 2073 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) |
| 2074 | return false; |
| 2075 | |
| 2076 | switch (a->mode) { |
| 2077 | case MPOL_BIND: |
| 2078 | /* Fall through */ |
| 2079 | case MPOL_INTERLEAVE: |
| 2080 | return !!nodes_equal(a->v.nodes, b->v.nodes); |
| 2081 | case MPOL_PREFERRED: |
| 2082 | return a->v.preferred_node == b->v.preferred_node; |
| 2083 | default: |
| 2084 | BUG(); |
| 2085 | return false; |
| 2086 | } |
| 2087 | } |
| 2088 | |
| 2089 | /* |
| 2090 | * Shared memory backing store policy support. |
| 2091 | * |
| 2092 | * Remember policies even when nobody has shared memory mapped. |
| 2093 | * The policies are kept in Red-Black tree linked from the inode. |
| 2094 | * They are protected by the sp->lock spinlock, which should be held |
| 2095 | * for any accesses to the tree. |
| 2096 | */ |
| 2097 | |
| 2098 | /* lookup first element intersecting start-end */ |
| 2099 | /* Caller holds sp->mutex */ |
| 2100 | static struct sp_node * |
| 2101 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) |
| 2102 | { |
| 2103 | struct rb_node *n = sp->root.rb_node; |
| 2104 | |
| 2105 | while (n) { |
| 2106 | struct sp_node *p = rb_entry(n, struct sp_node, nd); |
| 2107 | |
| 2108 | if (start >= p->end) |
| 2109 | n = n->rb_right; |
| 2110 | else if (end <= p->start) |
| 2111 | n = n->rb_left; |
| 2112 | else |
| 2113 | break; |
| 2114 | } |
| 2115 | if (!n) |
| 2116 | return NULL; |
| 2117 | for (;;) { |
| 2118 | struct sp_node *w = NULL; |
| 2119 | struct rb_node *prev = rb_prev(n); |
| 2120 | if (!prev) |
| 2121 | break; |
| 2122 | w = rb_entry(prev, struct sp_node, nd); |
| 2123 | if (w->end <= start) |
| 2124 | break; |
| 2125 | n = prev; |
| 2126 | } |
| 2127 | return rb_entry(n, struct sp_node, nd); |
| 2128 | } |
| 2129 | |
| 2130 | /* Insert a new shared policy into the list. */ |
| 2131 | /* Caller holds sp->lock */ |
| 2132 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) |
| 2133 | { |
| 2134 | struct rb_node **p = &sp->root.rb_node; |
| 2135 | struct rb_node *parent = NULL; |
| 2136 | struct sp_node *nd; |
| 2137 | |
| 2138 | while (*p) { |
| 2139 | parent = *p; |
| 2140 | nd = rb_entry(parent, struct sp_node, nd); |
| 2141 | if (new->start < nd->start) |
| 2142 | p = &(*p)->rb_left; |
| 2143 | else if (new->end > nd->end) |
| 2144 | p = &(*p)->rb_right; |
| 2145 | else |
| 2146 | BUG(); |
| 2147 | } |
| 2148 | rb_link_node(&new->nd, parent, p); |
| 2149 | rb_insert_color(&new->nd, &sp->root); |
| 2150 | pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, |
| 2151 | new->policy ? new->policy->mode : 0); |
| 2152 | } |
| 2153 | |
| 2154 | /* Find shared policy intersecting idx */ |
| 2155 | struct mempolicy * |
| 2156 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) |
| 2157 | { |
| 2158 | struct mempolicy *pol = NULL; |
| 2159 | struct sp_node *sn; |
| 2160 | |
| 2161 | if (!sp->root.rb_node) |
| 2162 | return NULL; |
| 2163 | mutex_lock(&sp->mutex); |
| 2164 | sn = sp_lookup(sp, idx, idx+1); |
| 2165 | if (sn) { |
| 2166 | mpol_get(sn->policy); |
| 2167 | pol = sn->policy; |
| 2168 | } |
| 2169 | mutex_unlock(&sp->mutex); |
| 2170 | return pol; |
| 2171 | } |
| 2172 | |
| 2173 | static void sp_free(struct sp_node *n) |
| 2174 | { |
| 2175 | mpol_put(n->policy); |
| 2176 | kmem_cache_free(sn_cache, n); |
| 2177 | } |
| 2178 | |
| 2179 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) |
| 2180 | { |
| 2181 | pr_debug("deleting %lx-l%lx\n", n->start, n->end); |
| 2182 | rb_erase(&n->nd, &sp->root); |
| 2183 | sp_free(n); |
| 2184 | } |
| 2185 | |
| 2186 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, |
| 2187 | struct mempolicy *pol) |
| 2188 | { |
| 2189 | struct sp_node *n; |
| 2190 | struct mempolicy *newpol; |
| 2191 | |
| 2192 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
| 2193 | if (!n) |
| 2194 | return NULL; |
| 2195 | |
| 2196 | newpol = mpol_dup(pol); |
| 2197 | if (IS_ERR(newpol)) { |
| 2198 | kmem_cache_free(sn_cache, n); |
| 2199 | return NULL; |
| 2200 | } |
| 2201 | newpol->flags |= MPOL_F_SHARED; |
| 2202 | |
| 2203 | n->start = start; |
| 2204 | n->end = end; |
| 2205 | n->policy = newpol; |
| 2206 | |
| 2207 | return n; |
| 2208 | } |
| 2209 | |
| 2210 | /* Replace a policy range. */ |
| 2211 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, |
| 2212 | unsigned long end, struct sp_node *new) |
| 2213 | { |
| 2214 | struct sp_node *n; |
| 2215 | int ret = 0; |
| 2216 | |
| 2217 | mutex_lock(&sp->mutex); |
| 2218 | n = sp_lookup(sp, start, end); |
| 2219 | /* Take care of old policies in the same range. */ |
| 2220 | while (n && n->start < end) { |
| 2221 | struct rb_node *next = rb_next(&n->nd); |
| 2222 | if (n->start >= start) { |
| 2223 | if (n->end <= end) |
| 2224 | sp_delete(sp, n); |
| 2225 | else |
| 2226 | n->start = end; |
| 2227 | } else { |
| 2228 | /* Old policy spanning whole new range. */ |
| 2229 | if (n->end > end) { |
| 2230 | struct sp_node *new2; |
| 2231 | new2 = sp_alloc(end, n->end, n->policy); |
| 2232 | if (!new2) { |
| 2233 | ret = -ENOMEM; |
| 2234 | goto out; |
| 2235 | } |
| 2236 | n->end = start; |
| 2237 | sp_insert(sp, new2); |
| 2238 | break; |
| 2239 | } else |
| 2240 | n->end = start; |
| 2241 | } |
| 2242 | if (!next) |
| 2243 | break; |
| 2244 | n = rb_entry(next, struct sp_node, nd); |
| 2245 | } |
| 2246 | if (new) |
| 2247 | sp_insert(sp, new); |
| 2248 | out: |
| 2249 | mutex_unlock(&sp->mutex); |
| 2250 | return ret; |
| 2251 | } |
| 2252 | |
| 2253 | /** |
| 2254 | * mpol_shared_policy_init - initialize shared policy for inode |
| 2255 | * @sp: pointer to inode shared policy |
| 2256 | * @mpol: struct mempolicy to install |
| 2257 | * |
| 2258 | * Install non-NULL @mpol in inode's shared policy rb-tree. |
| 2259 | * On entry, the current task has a reference on a non-NULL @mpol. |
| 2260 | * This must be released on exit. |
| 2261 | * This is called at get_inode() calls and we can use GFP_KERNEL. |
| 2262 | */ |
| 2263 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) |
| 2264 | { |
| 2265 | int ret; |
| 2266 | |
| 2267 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ |
| 2268 | mutex_init(&sp->mutex); |
| 2269 | |
| 2270 | if (mpol) { |
| 2271 | struct vm_area_struct pvma; |
| 2272 | struct mempolicy *new; |
| 2273 | NODEMASK_SCRATCH(scratch); |
| 2274 | |
| 2275 | if (!scratch) |
| 2276 | goto put_mpol; |
| 2277 | /* contextualize the tmpfs mount point mempolicy */ |
| 2278 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); |
| 2279 | if (IS_ERR(new)) |
| 2280 | goto free_scratch; /* no valid nodemask intersection */ |
| 2281 | |
| 2282 | task_lock(current); |
| 2283 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); |
| 2284 | task_unlock(current); |
| 2285 | if (ret) |
| 2286 | goto put_new; |
| 2287 | |
| 2288 | /* Create pseudo-vma that contains just the policy */ |
| 2289 | memset(&pvma, 0, sizeof(struct vm_area_struct)); |
| 2290 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ |
| 2291 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ |
| 2292 | |
| 2293 | put_new: |
| 2294 | mpol_put(new); /* drop initial ref */ |
| 2295 | free_scratch: |
| 2296 | NODEMASK_SCRATCH_FREE(scratch); |
| 2297 | put_mpol: |
| 2298 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ |
| 2299 | } |
| 2300 | } |
| 2301 | |
| 2302 | int mpol_set_shared_policy(struct shared_policy *info, |
| 2303 | struct vm_area_struct *vma, struct mempolicy *npol) |
| 2304 | { |
| 2305 | int err; |
| 2306 | struct sp_node *new = NULL; |
| 2307 | unsigned long sz = vma_pages(vma); |
| 2308 | |
| 2309 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", |
| 2310 | vma->vm_pgoff, |
| 2311 | sz, npol ? npol->mode : -1, |
| 2312 | npol ? npol->flags : -1, |
| 2313 | npol ? nodes_addr(npol->v.nodes)[0] : -1); |
| 2314 | |
| 2315 | if (npol) { |
| 2316 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); |
| 2317 | if (!new) |
| 2318 | return -ENOMEM; |
| 2319 | } |
| 2320 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); |
| 2321 | if (err && new) |
| 2322 | sp_free(new); |
| 2323 | return err; |
| 2324 | } |
| 2325 | |
| 2326 | /* Free a backing policy store on inode delete. */ |
| 2327 | void mpol_free_shared_policy(struct shared_policy *p) |
| 2328 | { |
| 2329 | struct sp_node *n; |
| 2330 | struct rb_node *next; |
| 2331 | |
| 2332 | if (!p->root.rb_node) |
| 2333 | return; |
| 2334 | mutex_lock(&p->mutex); |
| 2335 | next = rb_first(&p->root); |
| 2336 | while (next) { |
| 2337 | n = rb_entry(next, struct sp_node, nd); |
| 2338 | next = rb_next(&n->nd); |
| 2339 | sp_delete(p, n); |
| 2340 | } |
| 2341 | mutex_unlock(&p->mutex); |
| 2342 | } |
| 2343 | |
| 2344 | /* assumes fs == KERNEL_DS */ |
| 2345 | void __init numa_policy_init(void) |
| 2346 | { |
| 2347 | nodemask_t interleave_nodes; |
| 2348 | unsigned long largest = 0; |
| 2349 | int nid, prefer = 0; |
| 2350 | |
| 2351 | policy_cache = kmem_cache_create("numa_policy", |
| 2352 | sizeof(struct mempolicy), |
| 2353 | 0, SLAB_PANIC, NULL); |
| 2354 | |
| 2355 | sn_cache = kmem_cache_create("shared_policy_node", |
| 2356 | sizeof(struct sp_node), |
| 2357 | 0, SLAB_PANIC, NULL); |
| 2358 | |
| 2359 | /* |
| 2360 | * Set interleaving policy for system init. Interleaving is only |
| 2361 | * enabled across suitably sized nodes (default is >= 16MB), or |
| 2362 | * fall back to the largest node if they're all smaller. |
| 2363 | */ |
| 2364 | nodes_clear(interleave_nodes); |
| 2365 | for_each_node_state(nid, N_HIGH_MEMORY) { |
| 2366 | unsigned long total_pages = node_present_pages(nid); |
| 2367 | |
| 2368 | /* Preserve the largest node */ |
| 2369 | if (largest < total_pages) { |
| 2370 | largest = total_pages; |
| 2371 | prefer = nid; |
| 2372 | } |
| 2373 | |
| 2374 | /* Interleave this node? */ |
| 2375 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) |
| 2376 | node_set(nid, interleave_nodes); |
| 2377 | } |
| 2378 | |
| 2379 | /* All too small, use the largest */ |
| 2380 | if (unlikely(nodes_empty(interleave_nodes))) |
| 2381 | node_set(prefer, interleave_nodes); |
| 2382 | |
| 2383 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) |
| 2384 | printk("numa_policy_init: interleaving failed\n"); |
| 2385 | } |
| 2386 | |
| 2387 | /* Reset policy of current process to default */ |
| 2388 | void numa_default_policy(void) |
| 2389 | { |
| 2390 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); |
| 2391 | } |
| 2392 | |
| 2393 | /* |
| 2394 | * Parse and format mempolicy from/to strings |
| 2395 | */ |
| 2396 | |
| 2397 | /* |
| 2398 | * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag |
| 2399 | * Used only for mpol_parse_str() and mpol_to_str() |
| 2400 | */ |
| 2401 | #define MPOL_LOCAL MPOL_MAX |
| 2402 | static const char * const policy_modes[] = |
| 2403 | { |
| 2404 | [MPOL_DEFAULT] = "default", |
| 2405 | [MPOL_PREFERRED] = "prefer", |
| 2406 | [MPOL_BIND] = "bind", |
| 2407 | [MPOL_INTERLEAVE] = "interleave", |
| 2408 | [MPOL_LOCAL] = "local" |
| 2409 | }; |
| 2410 | |
| 2411 | |
| 2412 | #ifdef CONFIG_TMPFS |
| 2413 | /** |
| 2414 | * mpol_parse_str - parse string to mempolicy |
| 2415 | * @str: string containing mempolicy to parse |
| 2416 | * @mpol: pointer to struct mempolicy pointer, returned on success. |
| 2417 | * @no_context: flag whether to "contextualize" the mempolicy |
| 2418 | * |
| 2419 | * Format of input: |
| 2420 | * <mode>[=<flags>][:<nodelist>] |
| 2421 | * |
| 2422 | * if @no_context is true, save the input nodemask in w.user_nodemask in |
| 2423 | * the returned mempolicy. This will be used to "clone" the mempolicy in |
| 2424 | * a specific context [cpuset] at a later time. Used to parse tmpfs mpol |
| 2425 | * mount option. Note that if 'static' or 'relative' mode flags were |
| 2426 | * specified, the input nodemask will already have been saved. Saving |
| 2427 | * it again is redundant, but safe. |
| 2428 | * |
| 2429 | * On success, returns 0, else 1 |
| 2430 | */ |
| 2431 | int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) |
| 2432 | { |
| 2433 | struct mempolicy *new = NULL; |
| 2434 | unsigned short mode; |
| 2435 | unsigned short uninitialized_var(mode_flags); |
| 2436 | nodemask_t nodes; |
| 2437 | char *nodelist = strchr(str, ':'); |
| 2438 | char *flags = strchr(str, '='); |
| 2439 | int err = 1; |
| 2440 | |
| 2441 | if (nodelist) { |
| 2442 | /* NUL-terminate mode or flags string */ |
| 2443 | *nodelist++ = '\0'; |
| 2444 | if (nodelist_parse(nodelist, nodes)) |
| 2445 | goto out; |
| 2446 | if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY])) |
| 2447 | goto out; |
| 2448 | } else |
| 2449 | nodes_clear(nodes); |
| 2450 | |
| 2451 | if (flags) |
| 2452 | *flags++ = '\0'; /* terminate mode string */ |
| 2453 | |
| 2454 | for (mode = 0; mode <= MPOL_LOCAL; mode++) { |
| 2455 | if (!strcmp(str, policy_modes[mode])) { |
| 2456 | break; |
| 2457 | } |
| 2458 | } |
| 2459 | if (mode > MPOL_LOCAL) |
| 2460 | goto out; |
| 2461 | |
| 2462 | switch (mode) { |
| 2463 | case MPOL_PREFERRED: |
| 2464 | /* |
| 2465 | * Insist on a nodelist of one node only |
| 2466 | */ |
| 2467 | if (nodelist) { |
| 2468 | char *rest = nodelist; |
| 2469 | while (isdigit(*rest)) |
| 2470 | rest++; |
| 2471 | if (*rest) |
| 2472 | goto out; |
| 2473 | } |
| 2474 | break; |
| 2475 | case MPOL_INTERLEAVE: |
| 2476 | /* |
| 2477 | * Default to online nodes with memory if no nodelist |
| 2478 | */ |
| 2479 | if (!nodelist) |
| 2480 | nodes = node_states[N_HIGH_MEMORY]; |
| 2481 | break; |
| 2482 | case MPOL_LOCAL: |
| 2483 | /* |
| 2484 | * Don't allow a nodelist; mpol_new() checks flags |
| 2485 | */ |
| 2486 | if (nodelist) |
| 2487 | goto out; |
| 2488 | mode = MPOL_PREFERRED; |
| 2489 | break; |
| 2490 | case MPOL_DEFAULT: |
| 2491 | /* |
| 2492 | * Insist on a empty nodelist |
| 2493 | */ |
| 2494 | if (!nodelist) |
| 2495 | err = 0; |
| 2496 | goto out; |
| 2497 | case MPOL_BIND: |
| 2498 | /* |
| 2499 | * Insist on a nodelist |
| 2500 | */ |
| 2501 | if (!nodelist) |
| 2502 | goto out; |
| 2503 | } |
| 2504 | |
| 2505 | mode_flags = 0; |
| 2506 | if (flags) { |
| 2507 | /* |
| 2508 | * Currently, we only support two mutually exclusive |
| 2509 | * mode flags. |
| 2510 | */ |
| 2511 | if (!strcmp(flags, "static")) |
| 2512 | mode_flags |= MPOL_F_STATIC_NODES; |
| 2513 | else if (!strcmp(flags, "relative")) |
| 2514 | mode_flags |= MPOL_F_RELATIVE_NODES; |
| 2515 | else |
| 2516 | goto out; |
| 2517 | } |
| 2518 | |
| 2519 | new = mpol_new(mode, mode_flags, &nodes); |
| 2520 | if (IS_ERR(new)) |
| 2521 | goto out; |
| 2522 | |
| 2523 | if (no_context) { |
| 2524 | /* save for contextualization */ |
| 2525 | new->w.user_nodemask = nodes; |
| 2526 | } else { |
| 2527 | int ret; |
| 2528 | NODEMASK_SCRATCH(scratch); |
| 2529 | if (scratch) { |
| 2530 | task_lock(current); |
| 2531 | ret = mpol_set_nodemask(new, &nodes, scratch); |
| 2532 | task_unlock(current); |
| 2533 | } else |
| 2534 | ret = -ENOMEM; |
| 2535 | NODEMASK_SCRATCH_FREE(scratch); |
| 2536 | if (ret) { |
| 2537 | mpol_put(new); |
| 2538 | goto out; |
| 2539 | } |
| 2540 | } |
| 2541 | err = 0; |
| 2542 | |
| 2543 | out: |
| 2544 | /* Restore string for error message */ |
| 2545 | if (nodelist) |
| 2546 | *--nodelist = ':'; |
| 2547 | if (flags) |
| 2548 | *--flags = '='; |
| 2549 | if (!err) |
| 2550 | *mpol = new; |
| 2551 | return err; |
| 2552 | } |
| 2553 | #endif /* CONFIG_TMPFS */ |
| 2554 | |
| 2555 | /** |
| 2556 | * mpol_to_str - format a mempolicy structure for printing |
| 2557 | * @buffer: to contain formatted mempolicy string |
| 2558 | * @maxlen: length of @buffer |
| 2559 | * @pol: pointer to mempolicy to be formatted |
| 2560 | * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask |
| 2561 | * |
| 2562 | * Convert a mempolicy into a string. |
| 2563 | * Returns the number of characters in buffer (if positive) |
| 2564 | * or an error (negative) |
| 2565 | */ |
| 2566 | int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) |
| 2567 | { |
| 2568 | char *p = buffer; |
| 2569 | int l; |
| 2570 | nodemask_t nodes; |
| 2571 | unsigned short mode; |
| 2572 | unsigned short flags = pol ? pol->flags : 0; |
| 2573 | |
| 2574 | /* |
| 2575 | * Sanity check: room for longest mode, flag and some nodes |
| 2576 | */ |
| 2577 | VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); |
| 2578 | |
| 2579 | if (!pol || pol == &default_policy) |
| 2580 | mode = MPOL_DEFAULT; |
| 2581 | else |
| 2582 | mode = pol->mode; |
| 2583 | |
| 2584 | switch (mode) { |
| 2585 | case MPOL_DEFAULT: |
| 2586 | nodes_clear(nodes); |
| 2587 | break; |
| 2588 | |
| 2589 | case MPOL_PREFERRED: |
| 2590 | nodes_clear(nodes); |
| 2591 | if (flags & MPOL_F_LOCAL) |
| 2592 | mode = MPOL_LOCAL; /* pseudo-policy */ |
| 2593 | else |
| 2594 | node_set(pol->v.preferred_node, nodes); |
| 2595 | break; |
| 2596 | |
| 2597 | case MPOL_BIND: |
| 2598 | /* Fall through */ |
| 2599 | case MPOL_INTERLEAVE: |
| 2600 | if (no_context) |
| 2601 | nodes = pol->w.user_nodemask; |
| 2602 | else |
| 2603 | nodes = pol->v.nodes; |
| 2604 | break; |
| 2605 | |
| 2606 | default: |
| 2607 | return -EINVAL; |
| 2608 | } |
| 2609 | |
| 2610 | l = strlen(policy_modes[mode]); |
| 2611 | if (buffer + maxlen < p + l + 1) |
| 2612 | return -ENOSPC; |
| 2613 | |
| 2614 | strcpy(p, policy_modes[mode]); |
| 2615 | p += l; |
| 2616 | |
| 2617 | if (flags & MPOL_MODE_FLAGS) { |
| 2618 | if (buffer + maxlen < p + 2) |
| 2619 | return -ENOSPC; |
| 2620 | *p++ = '='; |
| 2621 | |
| 2622 | /* |
| 2623 | * Currently, the only defined flags are mutually exclusive |
| 2624 | */ |
| 2625 | if (flags & MPOL_F_STATIC_NODES) |
| 2626 | p += snprintf(p, buffer + maxlen - p, "static"); |
| 2627 | else if (flags & MPOL_F_RELATIVE_NODES) |
| 2628 | p += snprintf(p, buffer + maxlen - p, "relative"); |
| 2629 | } |
| 2630 | |
| 2631 | if (!nodes_empty(nodes)) { |
| 2632 | if (buffer + maxlen < p + 2) |
| 2633 | return -ENOSPC; |
| 2634 | *p++ = ':'; |
| 2635 | p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); |
| 2636 | } |
| 2637 | return p - buffer; |
| 2638 | } |