| 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 NUMA_NO_NODE 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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 69 | |
| 70 | #include <linux/mempolicy.h> |
| 71 | #include <linux/mm.h> |
| 72 | #include <linux/highmem.h> |
| 73 | #include <linux/hugetlb.h> |
| 74 | #include <linux/kernel.h> |
| 75 | #include <linux/sched.h> |
| 76 | #include <linux/nodemask.h> |
| 77 | #include <linux/cpuset.h> |
| 78 | #include <linux/slab.h> |
| 79 | #include <linux/string.h> |
| 80 | #include <linux/export.h> |
| 81 | #include <linux/nsproxy.h> |
| 82 | #include <linux/interrupt.h> |
| 83 | #include <linux/init.h> |
| 84 | #include <linux/compat.h> |
| 85 | #include <linux/swap.h> |
| 86 | #include <linux/seq_file.h> |
| 87 | #include <linux/proc_fs.h> |
| 88 | #include <linux/migrate.h> |
| 89 | #include <linux/ksm.h> |
| 90 | #include <linux/rmap.h> |
| 91 | #include <linux/security.h> |
| 92 | #include <linux/syscalls.h> |
| 93 | #include <linux/ctype.h> |
| 94 | #include <linux/mm_inline.h> |
| 95 | #include <linux/mmu_notifier.h> |
| 96 | #include <linux/printk.h> |
| 97 | |
| 98 | #include <asm/tlbflush.h> |
| 99 | #include <asm/uaccess.h> |
| 100 | |
| 101 | #include "internal.h" |
| 102 | |
| 103 | /* Internal flags */ |
| 104 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ |
| 105 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ |
| 106 | |
| 107 | static struct kmem_cache *policy_cache; |
| 108 | static struct kmem_cache *sn_cache; |
| 109 | |
| 110 | /* Highest zone. An specific allocation for a zone below that is not |
| 111 | policied. */ |
| 112 | enum zone_type policy_zone = 0; |
| 113 | |
| 114 | /* |
| 115 | * run-time system-wide default policy => local allocation |
| 116 | */ |
| 117 | static struct mempolicy default_policy = { |
| 118 | .refcnt = ATOMIC_INIT(1), /* never free it */ |
| 119 | .mode = MPOL_PREFERRED, |
| 120 | .flags = MPOL_F_LOCAL, |
| 121 | }; |
| 122 | |
| 123 | static struct mempolicy preferred_node_policy[MAX_NUMNODES]; |
| 124 | |
| 125 | struct mempolicy *get_task_policy(struct task_struct *p) |
| 126 | { |
| 127 | struct mempolicy *pol = p->mempolicy; |
| 128 | int node; |
| 129 | |
| 130 | if (pol) |
| 131 | return pol; |
| 132 | |
| 133 | node = numa_node_id(); |
| 134 | if (node != NUMA_NO_NODE) { |
| 135 | pol = &preferred_node_policy[node]; |
| 136 | /* preferred_node_policy is not initialised early in boot */ |
| 137 | if (pol->mode) |
| 138 | return pol; |
| 139 | } |
| 140 | |
| 141 | return &default_policy; |
| 142 | } |
| 143 | |
| 144 | static const struct mempolicy_operations { |
| 145 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); |
| 146 | /* |
| 147 | * If read-side task has no lock to protect task->mempolicy, write-side |
| 148 | * task will rebind the task->mempolicy by two step. The first step is |
| 149 | * setting all the newly nodes, and the second step is cleaning all the |
| 150 | * disallowed nodes. In this way, we can avoid finding no node to alloc |
| 151 | * page. |
| 152 | * If we have a lock to protect task->mempolicy in read-side, we do |
| 153 | * rebind directly. |
| 154 | * |
| 155 | * step: |
| 156 | * MPOL_REBIND_ONCE - do rebind work at once |
| 157 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 158 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 159 | */ |
| 160 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes, |
| 161 | enum mpol_rebind_step step); |
| 162 | } mpol_ops[MPOL_MAX]; |
| 163 | |
| 164 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) |
| 165 | { |
| 166 | return pol->flags & MPOL_MODE_FLAGS; |
| 167 | } |
| 168 | |
| 169 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, |
| 170 | const nodemask_t *rel) |
| 171 | { |
| 172 | nodemask_t tmp; |
| 173 | nodes_fold(tmp, *orig, nodes_weight(*rel)); |
| 174 | nodes_onto(*ret, tmp, *rel); |
| 175 | } |
| 176 | |
| 177 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) |
| 178 | { |
| 179 | if (nodes_empty(*nodes)) |
| 180 | return -EINVAL; |
| 181 | pol->v.nodes = *nodes; |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) |
| 186 | { |
| 187 | if (!nodes) |
| 188 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ |
| 189 | else if (nodes_empty(*nodes)) |
| 190 | return -EINVAL; /* no allowed nodes */ |
| 191 | else |
| 192 | pol->v.preferred_node = first_node(*nodes); |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) |
| 197 | { |
| 198 | if (nodes_empty(*nodes)) |
| 199 | return -EINVAL; |
| 200 | pol->v.nodes = *nodes; |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if |
| 206 | * any, for the new policy. mpol_new() has already validated the nodes |
| 207 | * parameter with respect to the policy mode and flags. But, we need to |
| 208 | * handle an empty nodemask with MPOL_PREFERRED here. |
| 209 | * |
| 210 | * Must be called holding task's alloc_lock to protect task's mems_allowed |
| 211 | * and mempolicy. May also be called holding the mmap_semaphore for write. |
| 212 | */ |
| 213 | static int mpol_set_nodemask(struct mempolicy *pol, |
| 214 | const nodemask_t *nodes, struct nodemask_scratch *nsc) |
| 215 | { |
| 216 | int ret; |
| 217 | |
| 218 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ |
| 219 | if (pol == NULL) |
| 220 | return 0; |
| 221 | /* Check N_MEMORY */ |
| 222 | nodes_and(nsc->mask1, |
| 223 | cpuset_current_mems_allowed, node_states[N_MEMORY]); |
| 224 | |
| 225 | VM_BUG_ON(!nodes); |
| 226 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) |
| 227 | nodes = NULL; /* explicit local allocation */ |
| 228 | else { |
| 229 | if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 230 | mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1); |
| 231 | else |
| 232 | nodes_and(nsc->mask2, *nodes, nsc->mask1); |
| 233 | |
| 234 | if (mpol_store_user_nodemask(pol)) |
| 235 | pol->w.user_nodemask = *nodes; |
| 236 | else |
| 237 | pol->w.cpuset_mems_allowed = |
| 238 | cpuset_current_mems_allowed; |
| 239 | } |
| 240 | |
| 241 | if (nodes) |
| 242 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); |
| 243 | else |
| 244 | ret = mpol_ops[pol->mode].create(pol, NULL); |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * This function just creates a new policy, does some check and simple |
| 250 | * initialization. You must invoke mpol_set_nodemask() to set nodes. |
| 251 | */ |
| 252 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, |
| 253 | nodemask_t *nodes) |
| 254 | { |
| 255 | struct mempolicy *policy; |
| 256 | |
| 257 | pr_debug("setting mode %d flags %d nodes[0] %lx\n", |
| 258 | mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE); |
| 259 | |
| 260 | if (mode == MPOL_DEFAULT) { |
| 261 | if (nodes && !nodes_empty(*nodes)) |
| 262 | return ERR_PTR(-EINVAL); |
| 263 | return NULL; |
| 264 | } |
| 265 | VM_BUG_ON(!nodes); |
| 266 | |
| 267 | /* |
| 268 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or |
| 269 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). |
| 270 | * All other modes require a valid pointer to a non-empty nodemask. |
| 271 | */ |
| 272 | if (mode == MPOL_PREFERRED) { |
| 273 | if (nodes_empty(*nodes)) { |
| 274 | if (((flags & MPOL_F_STATIC_NODES) || |
| 275 | (flags & MPOL_F_RELATIVE_NODES))) |
| 276 | return ERR_PTR(-EINVAL); |
| 277 | } |
| 278 | } else if (mode == MPOL_LOCAL) { |
| 279 | if (!nodes_empty(*nodes)) |
| 280 | return ERR_PTR(-EINVAL); |
| 281 | mode = MPOL_PREFERRED; |
| 282 | } else if (nodes_empty(*nodes)) |
| 283 | return ERR_PTR(-EINVAL); |
| 284 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 285 | if (!policy) |
| 286 | return ERR_PTR(-ENOMEM); |
| 287 | atomic_set(&policy->refcnt, 1); |
| 288 | policy->mode = mode; |
| 289 | policy->flags = flags; |
| 290 | |
| 291 | return policy; |
| 292 | } |
| 293 | |
| 294 | /* Slow path of a mpol destructor. */ |
| 295 | void __mpol_put(struct mempolicy *p) |
| 296 | { |
| 297 | if (!atomic_dec_and_test(&p->refcnt)) |
| 298 | return; |
| 299 | kmem_cache_free(policy_cache, p); |
| 300 | } |
| 301 | |
| 302 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes, |
| 303 | enum mpol_rebind_step step) |
| 304 | { |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * step: |
| 309 | * MPOL_REBIND_ONCE - do rebind work at once |
| 310 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 311 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 312 | */ |
| 313 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, |
| 314 | enum mpol_rebind_step step) |
| 315 | { |
| 316 | nodemask_t tmp; |
| 317 | |
| 318 | if (pol->flags & MPOL_F_STATIC_NODES) |
| 319 | nodes_and(tmp, pol->w.user_nodemask, *nodes); |
| 320 | else if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 321 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
| 322 | else { |
| 323 | /* |
| 324 | * if step == 1, we use ->w.cpuset_mems_allowed to cache the |
| 325 | * result |
| 326 | */ |
| 327 | if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) { |
| 328 | nodes_remap(tmp, pol->v.nodes, |
| 329 | pol->w.cpuset_mems_allowed, *nodes); |
| 330 | pol->w.cpuset_mems_allowed = step ? tmp : *nodes; |
| 331 | } else if (step == MPOL_REBIND_STEP2) { |
| 332 | tmp = pol->w.cpuset_mems_allowed; |
| 333 | pol->w.cpuset_mems_allowed = *nodes; |
| 334 | } else |
| 335 | BUG(); |
| 336 | } |
| 337 | |
| 338 | if (nodes_empty(tmp)) |
| 339 | tmp = *nodes; |
| 340 | |
| 341 | if (step == MPOL_REBIND_STEP1) |
| 342 | nodes_or(pol->v.nodes, pol->v.nodes, tmp); |
| 343 | else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2) |
| 344 | pol->v.nodes = tmp; |
| 345 | else |
| 346 | BUG(); |
| 347 | |
| 348 | if (!node_isset(current->il_next, tmp)) { |
| 349 | current->il_next = next_node_in(current->il_next, tmp); |
| 350 | if (current->il_next >= MAX_NUMNODES) |
| 351 | current->il_next = numa_node_id(); |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | static void mpol_rebind_preferred(struct mempolicy *pol, |
| 356 | const nodemask_t *nodes, |
| 357 | enum mpol_rebind_step step) |
| 358 | { |
| 359 | nodemask_t tmp; |
| 360 | |
| 361 | if (pol->flags & MPOL_F_STATIC_NODES) { |
| 362 | int node = first_node(pol->w.user_nodemask); |
| 363 | |
| 364 | if (node_isset(node, *nodes)) { |
| 365 | pol->v.preferred_node = node; |
| 366 | pol->flags &= ~MPOL_F_LOCAL; |
| 367 | } else |
| 368 | pol->flags |= MPOL_F_LOCAL; |
| 369 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { |
| 370 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
| 371 | pol->v.preferred_node = first_node(tmp); |
| 372 | } else if (!(pol->flags & MPOL_F_LOCAL)) { |
| 373 | pol->v.preferred_node = node_remap(pol->v.preferred_node, |
| 374 | pol->w.cpuset_mems_allowed, |
| 375 | *nodes); |
| 376 | pol->w.cpuset_mems_allowed = *nodes; |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * mpol_rebind_policy - Migrate a policy to a different set of nodes |
| 382 | * |
| 383 | * If read-side task has no lock to protect task->mempolicy, write-side |
| 384 | * task will rebind the task->mempolicy by two step. The first step is |
| 385 | * setting all the newly nodes, and the second step is cleaning all the |
| 386 | * disallowed nodes. In this way, we can avoid finding no node to alloc |
| 387 | * page. |
| 388 | * If we have a lock to protect task->mempolicy in read-side, we do |
| 389 | * rebind directly. |
| 390 | * |
| 391 | * step: |
| 392 | * MPOL_REBIND_ONCE - do rebind work at once |
| 393 | * MPOL_REBIND_STEP1 - set all the newly nodes |
| 394 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes |
| 395 | */ |
| 396 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, |
| 397 | enum mpol_rebind_step step) |
| 398 | { |
| 399 | if (!pol) |
| 400 | return; |
| 401 | if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE && |
| 402 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) |
| 403 | return; |
| 404 | |
| 405 | if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING)) |
| 406 | return; |
| 407 | |
| 408 | if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING)) |
| 409 | BUG(); |
| 410 | |
| 411 | if (step == MPOL_REBIND_STEP1) |
| 412 | pol->flags |= MPOL_F_REBINDING; |
| 413 | else if (step == MPOL_REBIND_STEP2) |
| 414 | pol->flags &= ~MPOL_F_REBINDING; |
| 415 | else if (step >= MPOL_REBIND_NSTEP) |
| 416 | BUG(); |
| 417 | |
| 418 | mpol_ops[pol->mode].rebind(pol, newmask, step); |
| 419 | } |
| 420 | |
| 421 | /* |
| 422 | * Wrapper for mpol_rebind_policy() that just requires task |
| 423 | * pointer, and updates task mempolicy. |
| 424 | * |
| 425 | * Called with task's alloc_lock held. |
| 426 | */ |
| 427 | |
| 428 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, |
| 429 | enum mpol_rebind_step step) |
| 430 | { |
| 431 | mpol_rebind_policy(tsk->mempolicy, new, step); |
| 432 | } |
| 433 | |
| 434 | /* |
| 435 | * Rebind each vma in mm to new nodemask. |
| 436 | * |
| 437 | * Call holding a reference to mm. Takes mm->mmap_sem during call. |
| 438 | */ |
| 439 | |
| 440 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) |
| 441 | { |
| 442 | struct vm_area_struct *vma; |
| 443 | |
| 444 | down_write(&mm->mmap_sem); |
| 445 | for (vma = mm->mmap; vma; vma = vma->vm_next) |
| 446 | mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); |
| 447 | up_write(&mm->mmap_sem); |
| 448 | } |
| 449 | |
| 450 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { |
| 451 | [MPOL_DEFAULT] = { |
| 452 | .rebind = mpol_rebind_default, |
| 453 | }, |
| 454 | [MPOL_INTERLEAVE] = { |
| 455 | .create = mpol_new_interleave, |
| 456 | .rebind = mpol_rebind_nodemask, |
| 457 | }, |
| 458 | [MPOL_PREFERRED] = { |
| 459 | .create = mpol_new_preferred, |
| 460 | .rebind = mpol_rebind_preferred, |
| 461 | }, |
| 462 | [MPOL_BIND] = { |
| 463 | .create = mpol_new_bind, |
| 464 | .rebind = mpol_rebind_nodemask, |
| 465 | }, |
| 466 | }; |
| 467 | |
| 468 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 469 | unsigned long flags); |
| 470 | |
| 471 | struct queue_pages { |
| 472 | struct list_head *pagelist; |
| 473 | unsigned long flags; |
| 474 | nodemask_t *nmask; |
| 475 | struct vm_area_struct *prev; |
| 476 | }; |
| 477 | |
| 478 | /* |
| 479 | * Scan through pages checking if pages follow certain conditions, |
| 480 | * and move them to the pagelist if they do. |
| 481 | */ |
| 482 | static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, |
| 483 | unsigned long end, struct mm_walk *walk) |
| 484 | { |
| 485 | struct vm_area_struct *vma = walk->vma; |
| 486 | struct page *page; |
| 487 | struct queue_pages *qp = walk->private; |
| 488 | unsigned long flags = qp->flags; |
| 489 | int nid, ret; |
| 490 | pte_t *pte; |
| 491 | spinlock_t *ptl; |
| 492 | |
| 493 | if (pmd_trans_huge(*pmd)) { |
| 494 | ptl = pmd_lock(walk->mm, pmd); |
| 495 | if (pmd_trans_huge(*pmd)) { |
| 496 | page = pmd_page(*pmd); |
| 497 | if (is_huge_zero_page(page)) { |
| 498 | spin_unlock(ptl); |
| 499 | split_huge_pmd(vma, pmd, addr); |
| 500 | } else { |
| 501 | get_page(page); |
| 502 | spin_unlock(ptl); |
| 503 | lock_page(page); |
| 504 | ret = split_huge_page(page); |
| 505 | unlock_page(page); |
| 506 | put_page(page); |
| 507 | if (ret) |
| 508 | return 0; |
| 509 | } |
| 510 | } else { |
| 511 | spin_unlock(ptl); |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | if (pmd_trans_unstable(pmd)) |
| 516 | return 0; |
| 517 | retry: |
| 518 | pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); |
| 519 | for (; addr != end; pte++, addr += PAGE_SIZE) { |
| 520 | if (!pte_present(*pte)) |
| 521 | continue; |
| 522 | page = vm_normal_page(vma, addr, *pte); |
| 523 | if (!page) |
| 524 | continue; |
| 525 | /* |
| 526 | * vm_normal_page() filters out zero pages, but there might |
| 527 | * still be PageReserved pages to skip, perhaps in a VDSO. |
| 528 | */ |
| 529 | if (PageReserved(page)) |
| 530 | continue; |
| 531 | nid = page_to_nid(page); |
| 532 | if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT)) |
| 533 | continue; |
| 534 | if (PageTransCompound(page)) { |
| 535 | get_page(page); |
| 536 | pte_unmap_unlock(pte, ptl); |
| 537 | lock_page(page); |
| 538 | ret = split_huge_page(page); |
| 539 | unlock_page(page); |
| 540 | put_page(page); |
| 541 | /* Failed to split -- skip. */ |
| 542 | if (ret) { |
| 543 | pte = pte_offset_map_lock(walk->mm, pmd, |
| 544 | addr, &ptl); |
| 545 | continue; |
| 546 | } |
| 547 | goto retry; |
| 548 | } |
| 549 | |
| 550 | migrate_page_add(page, qp->pagelist, flags); |
| 551 | } |
| 552 | pte_unmap_unlock(pte - 1, ptl); |
| 553 | cond_resched(); |
| 554 | return 0; |
| 555 | } |
| 556 | |
| 557 | static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, |
| 558 | unsigned long addr, unsigned long end, |
| 559 | struct mm_walk *walk) |
| 560 | { |
| 561 | #ifdef CONFIG_HUGETLB_PAGE |
| 562 | struct queue_pages *qp = walk->private; |
| 563 | unsigned long flags = qp->flags; |
| 564 | int nid; |
| 565 | struct page *page; |
| 566 | spinlock_t *ptl; |
| 567 | pte_t entry; |
| 568 | |
| 569 | ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); |
| 570 | entry = huge_ptep_get(pte); |
| 571 | if (!pte_present(entry)) |
| 572 | goto unlock; |
| 573 | page = pte_page(entry); |
| 574 | nid = page_to_nid(page); |
| 575 | if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT)) |
| 576 | goto unlock; |
| 577 | /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */ |
| 578 | if (flags & (MPOL_MF_MOVE_ALL) || |
| 579 | (flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) |
| 580 | isolate_huge_page(page, qp->pagelist); |
| 581 | unlock: |
| 582 | spin_unlock(ptl); |
| 583 | #else |
| 584 | BUG(); |
| 585 | #endif |
| 586 | return 0; |
| 587 | } |
| 588 | |
| 589 | #ifdef CONFIG_NUMA_BALANCING |
| 590 | /* |
| 591 | * This is used to mark a range of virtual addresses to be inaccessible. |
| 592 | * These are later cleared by a NUMA hinting fault. Depending on these |
| 593 | * faults, pages may be migrated for better NUMA placement. |
| 594 | * |
| 595 | * This is assuming that NUMA faults are handled using PROT_NONE. If |
| 596 | * an architecture makes a different choice, it will need further |
| 597 | * changes to the core. |
| 598 | */ |
| 599 | unsigned long change_prot_numa(struct vm_area_struct *vma, |
| 600 | unsigned long addr, unsigned long end) |
| 601 | { |
| 602 | int nr_updated; |
| 603 | |
| 604 | nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1); |
| 605 | if (nr_updated) |
| 606 | count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); |
| 607 | |
| 608 | return nr_updated; |
| 609 | } |
| 610 | #else |
| 611 | static unsigned long change_prot_numa(struct vm_area_struct *vma, |
| 612 | unsigned long addr, unsigned long end) |
| 613 | { |
| 614 | return 0; |
| 615 | } |
| 616 | #endif /* CONFIG_NUMA_BALANCING */ |
| 617 | |
| 618 | static int queue_pages_test_walk(unsigned long start, unsigned long end, |
| 619 | struct mm_walk *walk) |
| 620 | { |
| 621 | struct vm_area_struct *vma = walk->vma; |
| 622 | struct queue_pages *qp = walk->private; |
| 623 | unsigned long endvma = vma->vm_end; |
| 624 | unsigned long flags = qp->flags; |
| 625 | |
| 626 | if (!vma_migratable(vma)) |
| 627 | return 1; |
| 628 | |
| 629 | if (endvma > end) |
| 630 | endvma = end; |
| 631 | if (vma->vm_start > start) |
| 632 | start = vma->vm_start; |
| 633 | |
| 634 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { |
| 635 | if (!vma->vm_next && vma->vm_end < end) |
| 636 | return -EFAULT; |
| 637 | if (qp->prev && qp->prev->vm_end < vma->vm_start) |
| 638 | return -EFAULT; |
| 639 | } |
| 640 | |
| 641 | qp->prev = vma; |
| 642 | |
| 643 | if (flags & MPOL_MF_LAZY) { |
| 644 | /* Similar to task_numa_work, skip inaccessible VMAs */ |
| 645 | if (!is_vm_hugetlb_page(vma) && |
| 646 | (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) && |
| 647 | !(vma->vm_flags & VM_MIXEDMAP)) |
| 648 | change_prot_numa(vma, start, endvma); |
| 649 | return 1; |
| 650 | } |
| 651 | |
| 652 | /* queue pages from current vma */ |
| 653 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 654 | return 0; |
| 655 | return 1; |
| 656 | } |
| 657 | |
| 658 | /* |
| 659 | * Walk through page tables and collect pages to be migrated. |
| 660 | * |
| 661 | * If pages found in a given range are on a set of nodes (determined by |
| 662 | * @nodes and @flags,) it's isolated and queued to the pagelist which is |
| 663 | * passed via @private.) |
| 664 | */ |
| 665 | static int |
| 666 | queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end, |
| 667 | nodemask_t *nodes, unsigned long flags, |
| 668 | struct list_head *pagelist) |
| 669 | { |
| 670 | struct queue_pages qp = { |
| 671 | .pagelist = pagelist, |
| 672 | .flags = flags, |
| 673 | .nmask = nodes, |
| 674 | .prev = NULL, |
| 675 | }; |
| 676 | struct mm_walk queue_pages_walk = { |
| 677 | .hugetlb_entry = queue_pages_hugetlb, |
| 678 | .pmd_entry = queue_pages_pte_range, |
| 679 | .test_walk = queue_pages_test_walk, |
| 680 | .mm = mm, |
| 681 | .private = &qp, |
| 682 | }; |
| 683 | |
| 684 | return walk_page_range(start, end, &queue_pages_walk); |
| 685 | } |
| 686 | |
| 687 | /* |
| 688 | * Apply policy to a single VMA |
| 689 | * This must be called with the mmap_sem held for writing. |
| 690 | */ |
| 691 | static int vma_replace_policy(struct vm_area_struct *vma, |
| 692 | struct mempolicy *pol) |
| 693 | { |
| 694 | int err; |
| 695 | struct mempolicy *old; |
| 696 | struct mempolicy *new; |
| 697 | |
| 698 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", |
| 699 | vma->vm_start, vma->vm_end, vma->vm_pgoff, |
| 700 | vma->vm_ops, vma->vm_file, |
| 701 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); |
| 702 | |
| 703 | new = mpol_dup(pol); |
| 704 | if (IS_ERR(new)) |
| 705 | return PTR_ERR(new); |
| 706 | |
| 707 | if (vma->vm_ops && vma->vm_ops->set_policy) { |
| 708 | err = vma->vm_ops->set_policy(vma, new); |
| 709 | if (err) |
| 710 | goto err_out; |
| 711 | } |
| 712 | |
| 713 | old = vma->vm_policy; |
| 714 | vma->vm_policy = new; /* protected by mmap_sem */ |
| 715 | mpol_put(old); |
| 716 | |
| 717 | return 0; |
| 718 | err_out: |
| 719 | mpol_put(new); |
| 720 | return err; |
| 721 | } |
| 722 | |
| 723 | /* Step 2: apply policy to a range and do splits. */ |
| 724 | static int mbind_range(struct mm_struct *mm, unsigned long start, |
| 725 | unsigned long end, struct mempolicy *new_pol) |
| 726 | { |
| 727 | struct vm_area_struct *next; |
| 728 | struct vm_area_struct *prev; |
| 729 | struct vm_area_struct *vma; |
| 730 | int err = 0; |
| 731 | pgoff_t pgoff; |
| 732 | unsigned long vmstart; |
| 733 | unsigned long vmend; |
| 734 | |
| 735 | vma = find_vma(mm, start); |
| 736 | if (!vma || vma->vm_start > start) |
| 737 | return -EFAULT; |
| 738 | |
| 739 | prev = vma->vm_prev; |
| 740 | if (start > vma->vm_start) |
| 741 | prev = vma; |
| 742 | |
| 743 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { |
| 744 | next = vma->vm_next; |
| 745 | vmstart = max(start, vma->vm_start); |
| 746 | vmend = min(end, vma->vm_end); |
| 747 | |
| 748 | if (mpol_equal(vma_policy(vma), new_pol)) |
| 749 | continue; |
| 750 | |
| 751 | pgoff = vma->vm_pgoff + |
| 752 | ((vmstart - vma->vm_start) >> PAGE_SHIFT); |
| 753 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, |
| 754 | vma->anon_vma, vma->vm_file, pgoff, |
| 755 | new_pol, vma->vm_userfaultfd_ctx); |
| 756 | if (prev) { |
| 757 | vma = prev; |
| 758 | next = vma->vm_next; |
| 759 | if (mpol_equal(vma_policy(vma), new_pol)) |
| 760 | continue; |
| 761 | /* vma_merge() joined vma && vma->next, case 8 */ |
| 762 | goto replace; |
| 763 | } |
| 764 | if (vma->vm_start != vmstart) { |
| 765 | err = split_vma(vma->vm_mm, vma, vmstart, 1); |
| 766 | if (err) |
| 767 | goto out; |
| 768 | } |
| 769 | if (vma->vm_end != vmend) { |
| 770 | err = split_vma(vma->vm_mm, vma, vmend, 0); |
| 771 | if (err) |
| 772 | goto out; |
| 773 | } |
| 774 | replace: |
| 775 | err = vma_replace_policy(vma, new_pol); |
| 776 | if (err) |
| 777 | goto out; |
| 778 | } |
| 779 | |
| 780 | out: |
| 781 | return err; |
| 782 | } |
| 783 | |
| 784 | /* Set the process memory policy */ |
| 785 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, |
| 786 | nodemask_t *nodes) |
| 787 | { |
| 788 | struct mempolicy *new, *old; |
| 789 | NODEMASK_SCRATCH(scratch); |
| 790 | int ret; |
| 791 | |
| 792 | if (!scratch) |
| 793 | return -ENOMEM; |
| 794 | |
| 795 | new = mpol_new(mode, flags, nodes); |
| 796 | if (IS_ERR(new)) { |
| 797 | ret = PTR_ERR(new); |
| 798 | goto out; |
| 799 | } |
| 800 | |
| 801 | task_lock(current); |
| 802 | ret = mpol_set_nodemask(new, nodes, scratch); |
| 803 | if (ret) { |
| 804 | task_unlock(current); |
| 805 | mpol_put(new); |
| 806 | goto out; |
| 807 | } |
| 808 | old = current->mempolicy; |
| 809 | current->mempolicy = new; |
| 810 | if (new && new->mode == MPOL_INTERLEAVE && |
| 811 | nodes_weight(new->v.nodes)) |
| 812 | current->il_next = first_node(new->v.nodes); |
| 813 | task_unlock(current); |
| 814 | mpol_put(old); |
| 815 | ret = 0; |
| 816 | out: |
| 817 | NODEMASK_SCRATCH_FREE(scratch); |
| 818 | return ret; |
| 819 | } |
| 820 | |
| 821 | /* |
| 822 | * Return nodemask for policy for get_mempolicy() query |
| 823 | * |
| 824 | * Called with task's alloc_lock held |
| 825 | */ |
| 826 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) |
| 827 | { |
| 828 | nodes_clear(*nodes); |
| 829 | if (p == &default_policy) |
| 830 | return; |
| 831 | |
| 832 | switch (p->mode) { |
| 833 | case MPOL_BIND: |
| 834 | /* Fall through */ |
| 835 | case MPOL_INTERLEAVE: |
| 836 | *nodes = p->v.nodes; |
| 837 | break; |
| 838 | case MPOL_PREFERRED: |
| 839 | if (!(p->flags & MPOL_F_LOCAL)) |
| 840 | node_set(p->v.preferred_node, *nodes); |
| 841 | /* else return empty node mask for local allocation */ |
| 842 | break; |
| 843 | default: |
| 844 | BUG(); |
| 845 | } |
| 846 | } |
| 847 | |
| 848 | static int lookup_node(unsigned long addr) |
| 849 | { |
| 850 | struct page *p; |
| 851 | int err; |
| 852 | |
| 853 | err = get_user_pages(addr & PAGE_MASK, 1, 0, &p, NULL); |
| 854 | if (err >= 0) { |
| 855 | err = page_to_nid(p); |
| 856 | put_page(p); |
| 857 | } |
| 858 | return err; |
| 859 | } |
| 860 | |
| 861 | /* Retrieve NUMA policy */ |
| 862 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, |
| 863 | unsigned long addr, unsigned long flags) |
| 864 | { |
| 865 | int err; |
| 866 | struct mm_struct *mm = current->mm; |
| 867 | struct vm_area_struct *vma = NULL; |
| 868 | struct mempolicy *pol = current->mempolicy; |
| 869 | |
| 870 | if (flags & |
| 871 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) |
| 872 | return -EINVAL; |
| 873 | |
| 874 | if (flags & MPOL_F_MEMS_ALLOWED) { |
| 875 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) |
| 876 | return -EINVAL; |
| 877 | *policy = 0; /* just so it's initialized */ |
| 878 | task_lock(current); |
| 879 | *nmask = cpuset_current_mems_allowed; |
| 880 | task_unlock(current); |
| 881 | return 0; |
| 882 | } |
| 883 | |
| 884 | if (flags & MPOL_F_ADDR) { |
| 885 | /* |
| 886 | * Do NOT fall back to task policy if the |
| 887 | * vma/shared policy at addr is NULL. We |
| 888 | * want to return MPOL_DEFAULT in this case. |
| 889 | */ |
| 890 | down_read(&mm->mmap_sem); |
| 891 | vma = find_vma_intersection(mm, addr, addr+1); |
| 892 | if (!vma) { |
| 893 | up_read(&mm->mmap_sem); |
| 894 | return -EFAULT; |
| 895 | } |
| 896 | if (vma->vm_ops && vma->vm_ops->get_policy) |
| 897 | pol = vma->vm_ops->get_policy(vma, addr); |
| 898 | else |
| 899 | pol = vma->vm_policy; |
| 900 | } else if (addr) |
| 901 | return -EINVAL; |
| 902 | |
| 903 | if (!pol) |
| 904 | pol = &default_policy; /* indicates default behavior */ |
| 905 | |
| 906 | if (flags & MPOL_F_NODE) { |
| 907 | if (flags & MPOL_F_ADDR) { |
| 908 | err = lookup_node(addr); |
| 909 | if (err < 0) |
| 910 | goto out; |
| 911 | *policy = err; |
| 912 | } else if (pol == current->mempolicy && |
| 913 | pol->mode == MPOL_INTERLEAVE) { |
| 914 | *policy = current->il_next; |
| 915 | } else { |
| 916 | err = -EINVAL; |
| 917 | goto out; |
| 918 | } |
| 919 | } else { |
| 920 | *policy = pol == &default_policy ? MPOL_DEFAULT : |
| 921 | pol->mode; |
| 922 | /* |
| 923 | * Internal mempolicy flags must be masked off before exposing |
| 924 | * the policy to userspace. |
| 925 | */ |
| 926 | *policy |= (pol->flags & MPOL_MODE_FLAGS); |
| 927 | } |
| 928 | |
| 929 | if (vma) { |
| 930 | up_read(¤t->mm->mmap_sem); |
| 931 | vma = NULL; |
| 932 | } |
| 933 | |
| 934 | err = 0; |
| 935 | if (nmask) { |
| 936 | if (mpol_store_user_nodemask(pol)) { |
| 937 | *nmask = pol->w.user_nodemask; |
| 938 | } else { |
| 939 | task_lock(current); |
| 940 | get_policy_nodemask(pol, nmask); |
| 941 | task_unlock(current); |
| 942 | } |
| 943 | } |
| 944 | |
| 945 | out: |
| 946 | mpol_cond_put(pol); |
| 947 | if (vma) |
| 948 | up_read(¤t->mm->mmap_sem); |
| 949 | return err; |
| 950 | } |
| 951 | |
| 952 | #ifdef CONFIG_MIGRATION |
| 953 | /* |
| 954 | * page migration |
| 955 | */ |
| 956 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 957 | unsigned long flags) |
| 958 | { |
| 959 | /* |
| 960 | * Avoid migrating a page that is shared with others. |
| 961 | */ |
| 962 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { |
| 963 | if (!isolate_lru_page(page)) { |
| 964 | list_add_tail(&page->lru, pagelist); |
| 965 | inc_node_page_state(page, NR_ISOLATED_ANON + |
| 966 | page_is_file_cache(page)); |
| 967 | } |
| 968 | } |
| 969 | } |
| 970 | |
| 971 | static struct page *new_node_page(struct page *page, unsigned long node, int **x) |
| 972 | { |
| 973 | if (PageHuge(page)) |
| 974 | return alloc_huge_page_node(page_hstate(compound_head(page)), |
| 975 | node); |
| 976 | else |
| 977 | return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE | |
| 978 | __GFP_THISNODE, 0); |
| 979 | } |
| 980 | |
| 981 | /* |
| 982 | * Migrate pages from one node to a target node. |
| 983 | * Returns error or the number of pages not migrated. |
| 984 | */ |
| 985 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, |
| 986 | int flags) |
| 987 | { |
| 988 | nodemask_t nmask; |
| 989 | LIST_HEAD(pagelist); |
| 990 | int err = 0; |
| 991 | |
| 992 | nodes_clear(nmask); |
| 993 | node_set(source, nmask); |
| 994 | |
| 995 | /* |
| 996 | * This does not "check" the range but isolates all pages that |
| 997 | * need migration. Between passing in the full user address |
| 998 | * space range and MPOL_MF_DISCONTIG_OK, this call can not fail. |
| 999 | */ |
| 1000 | VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); |
| 1001 | queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, |
| 1002 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); |
| 1003 | |
| 1004 | if (!list_empty(&pagelist)) { |
| 1005 | err = migrate_pages(&pagelist, new_node_page, NULL, dest, |
| 1006 | MIGRATE_SYNC, MR_SYSCALL); |
| 1007 | if (err) |
| 1008 | putback_movable_pages(&pagelist); |
| 1009 | } |
| 1010 | |
| 1011 | return err; |
| 1012 | } |
| 1013 | |
| 1014 | /* |
| 1015 | * Move pages between the two nodesets so as to preserve the physical |
| 1016 | * layout as much as possible. |
| 1017 | * |
| 1018 | * Returns the number of page that could not be moved. |
| 1019 | */ |
| 1020 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 1021 | const nodemask_t *to, int flags) |
| 1022 | { |
| 1023 | int busy = 0; |
| 1024 | int err; |
| 1025 | nodemask_t tmp; |
| 1026 | |
| 1027 | err = migrate_prep(); |
| 1028 | if (err) |
| 1029 | return err; |
| 1030 | |
| 1031 | down_read(&mm->mmap_sem); |
| 1032 | |
| 1033 | /* |
| 1034 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' |
| 1035 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' |
| 1036 | * bit in 'tmp', and return that <source, dest> pair for migration. |
| 1037 | * The pair of nodemasks 'to' and 'from' define the map. |
| 1038 | * |
| 1039 | * If no pair of bits is found that way, fallback to picking some |
| 1040 | * pair of 'source' and 'dest' bits that are not the same. If the |
| 1041 | * 'source' and 'dest' bits are the same, this represents a node |
| 1042 | * that will be migrating to itself, so no pages need move. |
| 1043 | * |
| 1044 | * If no bits are left in 'tmp', or if all remaining bits left |
| 1045 | * in 'tmp' correspond to the same bit in 'to', return false |
| 1046 | * (nothing left to migrate). |
| 1047 | * |
| 1048 | * This lets us pick a pair of nodes to migrate between, such that |
| 1049 | * if possible the dest node is not already occupied by some other |
| 1050 | * source node, minimizing the risk of overloading the memory on a |
| 1051 | * node that would happen if we migrated incoming memory to a node |
| 1052 | * before migrating outgoing memory source that same node. |
| 1053 | * |
| 1054 | * A single scan of tmp is sufficient. As we go, we remember the |
| 1055 | * most recent <s, d> pair that moved (s != d). If we find a pair |
| 1056 | * that not only moved, but what's better, moved to an empty slot |
| 1057 | * (d is not set in tmp), then we break out then, with that pair. |
| 1058 | * Otherwise when we finish scanning from_tmp, we at least have the |
| 1059 | * most recent <s, d> pair that moved. If we get all the way through |
| 1060 | * the scan of tmp without finding any node that moved, much less |
| 1061 | * moved to an empty node, then there is nothing left worth migrating. |
| 1062 | */ |
| 1063 | |
| 1064 | tmp = *from; |
| 1065 | while (!nodes_empty(tmp)) { |
| 1066 | int s,d; |
| 1067 | int source = NUMA_NO_NODE; |
| 1068 | int dest = 0; |
| 1069 | |
| 1070 | for_each_node_mask(s, tmp) { |
| 1071 | |
| 1072 | /* |
| 1073 | * do_migrate_pages() tries to maintain the relative |
| 1074 | * node relationship of the pages established between |
| 1075 | * threads and memory areas. |
| 1076 | * |
| 1077 | * However if the number of source nodes is not equal to |
| 1078 | * the number of destination nodes we can not preserve |
| 1079 | * this node relative relationship. In that case, skip |
| 1080 | * copying memory from a node that is in the destination |
| 1081 | * mask. |
| 1082 | * |
| 1083 | * Example: [2,3,4] -> [3,4,5] moves everything. |
| 1084 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. |
| 1085 | */ |
| 1086 | |
| 1087 | if ((nodes_weight(*from) != nodes_weight(*to)) && |
| 1088 | (node_isset(s, *to))) |
| 1089 | continue; |
| 1090 | |
| 1091 | d = node_remap(s, *from, *to); |
| 1092 | if (s == d) |
| 1093 | continue; |
| 1094 | |
| 1095 | source = s; /* Node moved. Memorize */ |
| 1096 | dest = d; |
| 1097 | |
| 1098 | /* dest not in remaining from nodes? */ |
| 1099 | if (!node_isset(dest, tmp)) |
| 1100 | break; |
| 1101 | } |
| 1102 | if (source == NUMA_NO_NODE) |
| 1103 | break; |
| 1104 | |
| 1105 | node_clear(source, tmp); |
| 1106 | err = migrate_to_node(mm, source, dest, flags); |
| 1107 | if (err > 0) |
| 1108 | busy += err; |
| 1109 | if (err < 0) |
| 1110 | break; |
| 1111 | } |
| 1112 | up_read(&mm->mmap_sem); |
| 1113 | if (err < 0) |
| 1114 | return err; |
| 1115 | return busy; |
| 1116 | |
| 1117 | } |
| 1118 | |
| 1119 | /* |
| 1120 | * Allocate a new page for page migration based on vma policy. |
| 1121 | * Start by assuming the page is mapped by the same vma as contains @start. |
| 1122 | * Search forward from there, if not. N.B., this assumes that the |
| 1123 | * list of pages handed to migrate_pages()--which is how we get here-- |
| 1124 | * is in virtual address order. |
| 1125 | */ |
| 1126 | static struct page *new_page(struct page *page, unsigned long start, int **x) |
| 1127 | { |
| 1128 | struct vm_area_struct *vma; |
| 1129 | unsigned long uninitialized_var(address); |
| 1130 | |
| 1131 | vma = find_vma(current->mm, start); |
| 1132 | while (vma) { |
| 1133 | address = page_address_in_vma(page, vma); |
| 1134 | if (address != -EFAULT) |
| 1135 | break; |
| 1136 | vma = vma->vm_next; |
| 1137 | } |
| 1138 | |
| 1139 | if (PageHuge(page)) { |
| 1140 | BUG_ON(!vma); |
| 1141 | return alloc_huge_page_noerr(vma, address, 1); |
| 1142 | } |
| 1143 | /* |
| 1144 | * if !vma, alloc_page_vma() will use task or system default policy |
| 1145 | */ |
| 1146 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); |
| 1147 | } |
| 1148 | #else |
| 1149 | |
| 1150 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
| 1151 | unsigned long flags) |
| 1152 | { |
| 1153 | } |
| 1154 | |
| 1155 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 1156 | const nodemask_t *to, int flags) |
| 1157 | { |
| 1158 | return -ENOSYS; |
| 1159 | } |
| 1160 | |
| 1161 | static struct page *new_page(struct page *page, unsigned long start, int **x) |
| 1162 | { |
| 1163 | return NULL; |
| 1164 | } |
| 1165 | #endif |
| 1166 | |
| 1167 | static long do_mbind(unsigned long start, unsigned long len, |
| 1168 | unsigned short mode, unsigned short mode_flags, |
| 1169 | nodemask_t *nmask, unsigned long flags) |
| 1170 | { |
| 1171 | struct mm_struct *mm = current->mm; |
| 1172 | struct mempolicy *new; |
| 1173 | unsigned long end; |
| 1174 | int err; |
| 1175 | LIST_HEAD(pagelist); |
| 1176 | |
| 1177 | if (flags & ~(unsigned long)MPOL_MF_VALID) |
| 1178 | return -EINVAL; |
| 1179 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) |
| 1180 | return -EPERM; |
| 1181 | |
| 1182 | if (start & ~PAGE_MASK) |
| 1183 | return -EINVAL; |
| 1184 | |
| 1185 | if (mode == MPOL_DEFAULT) |
| 1186 | flags &= ~MPOL_MF_STRICT; |
| 1187 | |
| 1188 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; |
| 1189 | end = start + len; |
| 1190 | |
| 1191 | if (end < start) |
| 1192 | return -EINVAL; |
| 1193 | if (end == start) |
| 1194 | return 0; |
| 1195 | |
| 1196 | new = mpol_new(mode, mode_flags, nmask); |
| 1197 | if (IS_ERR(new)) |
| 1198 | return PTR_ERR(new); |
| 1199 | |
| 1200 | if (flags & MPOL_MF_LAZY) |
| 1201 | new->flags |= MPOL_F_MOF; |
| 1202 | |
| 1203 | /* |
| 1204 | * If we are using the default policy then operation |
| 1205 | * on discontinuous address spaces is okay after all |
| 1206 | */ |
| 1207 | if (!new) |
| 1208 | flags |= MPOL_MF_DISCONTIG_OK; |
| 1209 | |
| 1210 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", |
| 1211 | start, start + len, mode, mode_flags, |
| 1212 | nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE); |
| 1213 | |
| 1214 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { |
| 1215 | |
| 1216 | err = migrate_prep(); |
| 1217 | if (err) |
| 1218 | goto mpol_out; |
| 1219 | } |
| 1220 | { |
| 1221 | NODEMASK_SCRATCH(scratch); |
| 1222 | if (scratch) { |
| 1223 | down_write(&mm->mmap_sem); |
| 1224 | task_lock(current); |
| 1225 | err = mpol_set_nodemask(new, nmask, scratch); |
| 1226 | task_unlock(current); |
| 1227 | if (err) |
| 1228 | up_write(&mm->mmap_sem); |
| 1229 | } else |
| 1230 | err = -ENOMEM; |
| 1231 | NODEMASK_SCRATCH_FREE(scratch); |
| 1232 | } |
| 1233 | if (err) |
| 1234 | goto mpol_out; |
| 1235 | |
| 1236 | err = queue_pages_range(mm, start, end, nmask, |
| 1237 | flags | MPOL_MF_INVERT, &pagelist); |
| 1238 | if (!err) |
| 1239 | err = mbind_range(mm, start, end, new); |
| 1240 | |
| 1241 | if (!err) { |
| 1242 | int nr_failed = 0; |
| 1243 | |
| 1244 | if (!list_empty(&pagelist)) { |
| 1245 | WARN_ON_ONCE(flags & MPOL_MF_LAZY); |
| 1246 | nr_failed = migrate_pages(&pagelist, new_page, NULL, |
| 1247 | start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND); |
| 1248 | if (nr_failed) |
| 1249 | putback_movable_pages(&pagelist); |
| 1250 | } |
| 1251 | |
| 1252 | if (nr_failed && (flags & MPOL_MF_STRICT)) |
| 1253 | err = -EIO; |
| 1254 | } else |
| 1255 | putback_movable_pages(&pagelist); |
| 1256 | |
| 1257 | up_write(&mm->mmap_sem); |
| 1258 | mpol_out: |
| 1259 | mpol_put(new); |
| 1260 | return err; |
| 1261 | } |
| 1262 | |
| 1263 | /* |
| 1264 | * User space interface with variable sized bitmaps for nodelists. |
| 1265 | */ |
| 1266 | |
| 1267 | /* Copy a node mask from user space. */ |
| 1268 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, |
| 1269 | unsigned long maxnode) |
| 1270 | { |
| 1271 | unsigned long k; |
| 1272 | unsigned long nlongs; |
| 1273 | unsigned long endmask; |
| 1274 | |
| 1275 | --maxnode; |
| 1276 | nodes_clear(*nodes); |
| 1277 | if (maxnode == 0 || !nmask) |
| 1278 | return 0; |
| 1279 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) |
| 1280 | return -EINVAL; |
| 1281 | |
| 1282 | nlongs = BITS_TO_LONGS(maxnode); |
| 1283 | if ((maxnode % BITS_PER_LONG) == 0) |
| 1284 | endmask = ~0UL; |
| 1285 | else |
| 1286 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; |
| 1287 | |
| 1288 | /* When the user specified more nodes than supported just check |
| 1289 | if the non supported part is all zero. */ |
| 1290 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { |
| 1291 | if (nlongs > PAGE_SIZE/sizeof(long)) |
| 1292 | return -EINVAL; |
| 1293 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { |
| 1294 | unsigned long t; |
| 1295 | if (get_user(t, nmask + k)) |
| 1296 | return -EFAULT; |
| 1297 | if (k == nlongs - 1) { |
| 1298 | if (t & endmask) |
| 1299 | return -EINVAL; |
| 1300 | } else if (t) |
| 1301 | return -EINVAL; |
| 1302 | } |
| 1303 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); |
| 1304 | endmask = ~0UL; |
| 1305 | } |
| 1306 | |
| 1307 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) |
| 1308 | return -EFAULT; |
| 1309 | nodes_addr(*nodes)[nlongs-1] &= endmask; |
| 1310 | return 0; |
| 1311 | } |
| 1312 | |
| 1313 | /* Copy a kernel node mask to user space */ |
| 1314 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, |
| 1315 | nodemask_t *nodes) |
| 1316 | { |
| 1317 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; |
| 1318 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); |
| 1319 | |
| 1320 | if (copy > nbytes) { |
| 1321 | if (copy > PAGE_SIZE) |
| 1322 | return -EINVAL; |
| 1323 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) |
| 1324 | return -EFAULT; |
| 1325 | copy = nbytes; |
| 1326 | } |
| 1327 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; |
| 1328 | } |
| 1329 | |
| 1330 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, |
| 1331 | unsigned long, mode, const unsigned long __user *, nmask, |
| 1332 | unsigned long, maxnode, unsigned, flags) |
| 1333 | { |
| 1334 | nodemask_t nodes; |
| 1335 | int err; |
| 1336 | unsigned short mode_flags; |
| 1337 | |
| 1338 | mode_flags = mode & MPOL_MODE_FLAGS; |
| 1339 | mode &= ~MPOL_MODE_FLAGS; |
| 1340 | if (mode >= MPOL_MAX) |
| 1341 | return -EINVAL; |
| 1342 | if ((mode_flags & MPOL_F_STATIC_NODES) && |
| 1343 | (mode_flags & MPOL_F_RELATIVE_NODES)) |
| 1344 | return -EINVAL; |
| 1345 | err = get_nodes(&nodes, nmask, maxnode); |
| 1346 | if (err) |
| 1347 | return err; |
| 1348 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); |
| 1349 | } |
| 1350 | |
| 1351 | /* Set the process memory policy */ |
| 1352 | SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask, |
| 1353 | unsigned long, maxnode) |
| 1354 | { |
| 1355 | int err; |
| 1356 | nodemask_t nodes; |
| 1357 | unsigned short flags; |
| 1358 | |
| 1359 | flags = mode & MPOL_MODE_FLAGS; |
| 1360 | mode &= ~MPOL_MODE_FLAGS; |
| 1361 | if ((unsigned int)mode >= MPOL_MAX) |
| 1362 | return -EINVAL; |
| 1363 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) |
| 1364 | return -EINVAL; |
| 1365 | err = get_nodes(&nodes, nmask, maxnode); |
| 1366 | if (err) |
| 1367 | return err; |
| 1368 | return do_set_mempolicy(mode, flags, &nodes); |
| 1369 | } |
| 1370 | |
| 1371 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, |
| 1372 | const unsigned long __user *, old_nodes, |
| 1373 | const unsigned long __user *, new_nodes) |
| 1374 | { |
| 1375 | const struct cred *cred = current_cred(), *tcred; |
| 1376 | struct mm_struct *mm = NULL; |
| 1377 | struct task_struct *task; |
| 1378 | nodemask_t task_nodes; |
| 1379 | int err; |
| 1380 | nodemask_t *old; |
| 1381 | nodemask_t *new; |
| 1382 | NODEMASK_SCRATCH(scratch); |
| 1383 | |
| 1384 | if (!scratch) |
| 1385 | return -ENOMEM; |
| 1386 | |
| 1387 | old = &scratch->mask1; |
| 1388 | new = &scratch->mask2; |
| 1389 | |
| 1390 | err = get_nodes(old, old_nodes, maxnode); |
| 1391 | if (err) |
| 1392 | goto out; |
| 1393 | |
| 1394 | err = get_nodes(new, new_nodes, maxnode); |
| 1395 | if (err) |
| 1396 | goto out; |
| 1397 | |
| 1398 | /* Find the mm_struct */ |
| 1399 | rcu_read_lock(); |
| 1400 | task = pid ? find_task_by_vpid(pid) : current; |
| 1401 | if (!task) { |
| 1402 | rcu_read_unlock(); |
| 1403 | err = -ESRCH; |
| 1404 | goto out; |
| 1405 | } |
| 1406 | get_task_struct(task); |
| 1407 | |
| 1408 | err = -EINVAL; |
| 1409 | |
| 1410 | /* |
| 1411 | * Check if this process has the right to modify the specified |
| 1412 | * process. The right exists if the process has administrative |
| 1413 | * capabilities, superuser privileges or the same |
| 1414 | * userid as the target process. |
| 1415 | */ |
| 1416 | tcred = __task_cred(task); |
| 1417 | if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) && |
| 1418 | !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) && |
| 1419 | !capable(CAP_SYS_NICE)) { |
| 1420 | rcu_read_unlock(); |
| 1421 | err = -EPERM; |
| 1422 | goto out_put; |
| 1423 | } |
| 1424 | rcu_read_unlock(); |
| 1425 | |
| 1426 | task_nodes = cpuset_mems_allowed(task); |
| 1427 | /* Is the user allowed to access the target nodes? */ |
| 1428 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { |
| 1429 | err = -EPERM; |
| 1430 | goto out_put; |
| 1431 | } |
| 1432 | |
| 1433 | if (!nodes_subset(*new, node_states[N_MEMORY])) { |
| 1434 | err = -EINVAL; |
| 1435 | goto out_put; |
| 1436 | } |
| 1437 | |
| 1438 | err = security_task_movememory(task); |
| 1439 | if (err) |
| 1440 | goto out_put; |
| 1441 | |
| 1442 | mm = get_task_mm(task); |
| 1443 | put_task_struct(task); |
| 1444 | |
| 1445 | if (!mm) { |
| 1446 | err = -EINVAL; |
| 1447 | goto out; |
| 1448 | } |
| 1449 | |
| 1450 | err = do_migrate_pages(mm, old, new, |
| 1451 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); |
| 1452 | |
| 1453 | mmput(mm); |
| 1454 | out: |
| 1455 | NODEMASK_SCRATCH_FREE(scratch); |
| 1456 | |
| 1457 | return err; |
| 1458 | |
| 1459 | out_put: |
| 1460 | put_task_struct(task); |
| 1461 | goto out; |
| 1462 | |
| 1463 | } |
| 1464 | |
| 1465 | |
| 1466 | /* Retrieve NUMA policy */ |
| 1467 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
| 1468 | unsigned long __user *, nmask, unsigned long, maxnode, |
| 1469 | unsigned long, addr, unsigned long, flags) |
| 1470 | { |
| 1471 | int err; |
| 1472 | int uninitialized_var(pval); |
| 1473 | nodemask_t nodes; |
| 1474 | |
| 1475 | if (nmask != NULL && maxnode < MAX_NUMNODES) |
| 1476 | return -EINVAL; |
| 1477 | |
| 1478 | err = do_get_mempolicy(&pval, &nodes, addr, flags); |
| 1479 | |
| 1480 | if (err) |
| 1481 | return err; |
| 1482 | |
| 1483 | if (policy && put_user(pval, policy)) |
| 1484 | return -EFAULT; |
| 1485 | |
| 1486 | if (nmask) |
| 1487 | err = copy_nodes_to_user(nmask, maxnode, &nodes); |
| 1488 | |
| 1489 | return err; |
| 1490 | } |
| 1491 | |
| 1492 | #ifdef CONFIG_COMPAT |
| 1493 | |
| 1494 | COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
| 1495 | compat_ulong_t __user *, nmask, |
| 1496 | compat_ulong_t, maxnode, |
| 1497 | compat_ulong_t, addr, compat_ulong_t, flags) |
| 1498 | { |
| 1499 | long err; |
| 1500 | unsigned long __user *nm = NULL; |
| 1501 | unsigned long nr_bits, alloc_size; |
| 1502 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
| 1503 | |
| 1504 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1505 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1506 | |
| 1507 | if (nmask) |
| 1508 | nm = compat_alloc_user_space(alloc_size); |
| 1509 | |
| 1510 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); |
| 1511 | |
| 1512 | if (!err && nmask) { |
| 1513 | unsigned long copy_size; |
| 1514 | copy_size = min_t(unsigned long, sizeof(bm), alloc_size); |
| 1515 | err = copy_from_user(bm, nm, copy_size); |
| 1516 | /* ensure entire bitmap is zeroed */ |
| 1517 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); |
| 1518 | err |= compat_put_bitmap(nmask, bm, nr_bits); |
| 1519 | } |
| 1520 | |
| 1521 | return err; |
| 1522 | } |
| 1523 | |
| 1524 | COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask, |
| 1525 | compat_ulong_t, maxnode) |
| 1526 | { |
| 1527 | long err = 0; |
| 1528 | unsigned long __user *nm = NULL; |
| 1529 | unsigned long nr_bits, alloc_size; |
| 1530 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
| 1531 | |
| 1532 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1533 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1534 | |
| 1535 | if (nmask) { |
| 1536 | err = compat_get_bitmap(bm, nmask, nr_bits); |
| 1537 | nm = compat_alloc_user_space(alloc_size); |
| 1538 | err |= copy_to_user(nm, bm, alloc_size); |
| 1539 | } |
| 1540 | |
| 1541 | if (err) |
| 1542 | return -EFAULT; |
| 1543 | |
| 1544 | return sys_set_mempolicy(mode, nm, nr_bits+1); |
| 1545 | } |
| 1546 | |
| 1547 | COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len, |
| 1548 | compat_ulong_t, mode, compat_ulong_t __user *, nmask, |
| 1549 | compat_ulong_t, maxnode, compat_ulong_t, flags) |
| 1550 | { |
| 1551 | long err = 0; |
| 1552 | unsigned long __user *nm = NULL; |
| 1553 | unsigned long nr_bits, alloc_size; |
| 1554 | nodemask_t bm; |
| 1555 | |
| 1556 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
| 1557 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
| 1558 | |
| 1559 | if (nmask) { |
| 1560 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); |
| 1561 | nm = compat_alloc_user_space(alloc_size); |
| 1562 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); |
| 1563 | } |
| 1564 | |
| 1565 | if (err) |
| 1566 | return -EFAULT; |
| 1567 | |
| 1568 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); |
| 1569 | } |
| 1570 | |
| 1571 | #endif |
| 1572 | |
| 1573 | struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, |
| 1574 | unsigned long addr) |
| 1575 | { |
| 1576 | struct mempolicy *pol = NULL; |
| 1577 | |
| 1578 | if (vma) { |
| 1579 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
| 1580 | pol = vma->vm_ops->get_policy(vma, addr); |
| 1581 | } else if (vma->vm_policy) { |
| 1582 | pol = vma->vm_policy; |
| 1583 | |
| 1584 | /* |
| 1585 | * shmem_alloc_page() passes MPOL_F_SHARED policy with |
| 1586 | * a pseudo vma whose vma->vm_ops=NULL. Take a reference |
| 1587 | * count on these policies which will be dropped by |
| 1588 | * mpol_cond_put() later |
| 1589 | */ |
| 1590 | if (mpol_needs_cond_ref(pol)) |
| 1591 | mpol_get(pol); |
| 1592 | } |
| 1593 | } |
| 1594 | |
| 1595 | return pol; |
| 1596 | } |
| 1597 | |
| 1598 | /* |
| 1599 | * get_vma_policy(@vma, @addr) |
| 1600 | * @vma: virtual memory area whose policy is sought |
| 1601 | * @addr: address in @vma for shared policy lookup |
| 1602 | * |
| 1603 | * Returns effective policy for a VMA at specified address. |
| 1604 | * Falls back to current->mempolicy or system default policy, as necessary. |
| 1605 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference |
| 1606 | * count--added by the get_policy() vm_op, as appropriate--to protect against |
| 1607 | * freeing by another task. It is the caller's responsibility to free the |
| 1608 | * extra reference for shared policies. |
| 1609 | */ |
| 1610 | static struct mempolicy *get_vma_policy(struct vm_area_struct *vma, |
| 1611 | unsigned long addr) |
| 1612 | { |
| 1613 | struct mempolicy *pol = __get_vma_policy(vma, addr); |
| 1614 | |
| 1615 | if (!pol) |
| 1616 | pol = get_task_policy(current); |
| 1617 | |
| 1618 | return pol; |
| 1619 | } |
| 1620 | |
| 1621 | bool vma_policy_mof(struct vm_area_struct *vma) |
| 1622 | { |
| 1623 | struct mempolicy *pol; |
| 1624 | |
| 1625 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
| 1626 | bool ret = false; |
| 1627 | |
| 1628 | pol = vma->vm_ops->get_policy(vma, vma->vm_start); |
| 1629 | if (pol && (pol->flags & MPOL_F_MOF)) |
| 1630 | ret = true; |
| 1631 | mpol_cond_put(pol); |
| 1632 | |
| 1633 | return ret; |
| 1634 | } |
| 1635 | |
| 1636 | pol = vma->vm_policy; |
| 1637 | if (!pol) |
| 1638 | pol = get_task_policy(current); |
| 1639 | |
| 1640 | return pol->flags & MPOL_F_MOF; |
| 1641 | } |
| 1642 | |
| 1643 | static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) |
| 1644 | { |
| 1645 | enum zone_type dynamic_policy_zone = policy_zone; |
| 1646 | |
| 1647 | BUG_ON(dynamic_policy_zone == ZONE_MOVABLE); |
| 1648 | |
| 1649 | /* |
| 1650 | * if policy->v.nodes has movable memory only, |
| 1651 | * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only. |
| 1652 | * |
| 1653 | * policy->v.nodes is intersect with node_states[N_MEMORY]. |
| 1654 | * so if the following test faile, it implies |
| 1655 | * policy->v.nodes has movable memory only. |
| 1656 | */ |
| 1657 | if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY])) |
| 1658 | dynamic_policy_zone = ZONE_MOVABLE; |
| 1659 | |
| 1660 | return zone >= dynamic_policy_zone; |
| 1661 | } |
| 1662 | |
| 1663 | /* |
| 1664 | * Return a nodemask representing a mempolicy for filtering nodes for |
| 1665 | * page allocation |
| 1666 | */ |
| 1667 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) |
| 1668 | { |
| 1669 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ |
| 1670 | if (unlikely(policy->mode == MPOL_BIND) && |
| 1671 | apply_policy_zone(policy, gfp_zone(gfp)) && |
| 1672 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) |
| 1673 | return &policy->v.nodes; |
| 1674 | |
| 1675 | return NULL; |
| 1676 | } |
| 1677 | |
| 1678 | /* Return a zonelist indicated by gfp for node representing a mempolicy */ |
| 1679 | static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy, |
| 1680 | int nd) |
| 1681 | { |
| 1682 | switch (policy->mode) { |
| 1683 | case MPOL_PREFERRED: |
| 1684 | if (!(policy->flags & MPOL_F_LOCAL)) |
| 1685 | nd = policy->v.preferred_node; |
| 1686 | break; |
| 1687 | case MPOL_BIND: |
| 1688 | /* |
| 1689 | * Normally, MPOL_BIND allocations are node-local within the |
| 1690 | * allowed nodemask. However, if __GFP_THISNODE is set and the |
| 1691 | * current node isn't part of the mask, we use the zonelist for |
| 1692 | * the first node in the mask instead. |
| 1693 | */ |
| 1694 | if (unlikely(gfp & __GFP_THISNODE) && |
| 1695 | unlikely(!node_isset(nd, policy->v.nodes))) |
| 1696 | nd = first_node(policy->v.nodes); |
| 1697 | break; |
| 1698 | default: |
| 1699 | BUG(); |
| 1700 | } |
| 1701 | return node_zonelist(nd, gfp); |
| 1702 | } |
| 1703 | |
| 1704 | /* Do dynamic interleaving for a process */ |
| 1705 | static unsigned interleave_nodes(struct mempolicy *policy) |
| 1706 | { |
| 1707 | unsigned nid, next; |
| 1708 | struct task_struct *me = current; |
| 1709 | |
| 1710 | nid = me->il_next; |
| 1711 | next = next_node_in(nid, policy->v.nodes); |
| 1712 | if (next < MAX_NUMNODES) |
| 1713 | me->il_next = next; |
| 1714 | return nid; |
| 1715 | } |
| 1716 | |
| 1717 | /* |
| 1718 | * Depending on the memory policy provide a node from which to allocate the |
| 1719 | * next slab entry. |
| 1720 | */ |
| 1721 | unsigned int mempolicy_slab_node(void) |
| 1722 | { |
| 1723 | struct mempolicy *policy; |
| 1724 | int node = numa_mem_id(); |
| 1725 | |
| 1726 | if (in_interrupt()) |
| 1727 | return node; |
| 1728 | |
| 1729 | policy = current->mempolicy; |
| 1730 | if (!policy || policy->flags & MPOL_F_LOCAL) |
| 1731 | return node; |
| 1732 | |
| 1733 | switch (policy->mode) { |
| 1734 | case MPOL_PREFERRED: |
| 1735 | /* |
| 1736 | * handled MPOL_F_LOCAL above |
| 1737 | */ |
| 1738 | return policy->v.preferred_node; |
| 1739 | |
| 1740 | case MPOL_INTERLEAVE: |
| 1741 | return interleave_nodes(policy); |
| 1742 | |
| 1743 | case MPOL_BIND: { |
| 1744 | struct zoneref *z; |
| 1745 | |
| 1746 | /* |
| 1747 | * Follow bind policy behavior and start allocation at the |
| 1748 | * first node. |
| 1749 | */ |
| 1750 | struct zonelist *zonelist; |
| 1751 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); |
| 1752 | zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK]; |
| 1753 | z = first_zones_zonelist(zonelist, highest_zoneidx, |
| 1754 | &policy->v.nodes); |
| 1755 | return z->zone ? z->zone->node : node; |
| 1756 | } |
| 1757 | |
| 1758 | default: |
| 1759 | BUG(); |
| 1760 | } |
| 1761 | } |
| 1762 | |
| 1763 | /* |
| 1764 | * Do static interleaving for a VMA with known offset @n. Returns the n'th |
| 1765 | * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the |
| 1766 | * number of present nodes. |
| 1767 | */ |
| 1768 | static unsigned offset_il_node(struct mempolicy *pol, |
| 1769 | struct vm_area_struct *vma, unsigned long n) |
| 1770 | { |
| 1771 | unsigned nnodes = nodes_weight(pol->v.nodes); |
| 1772 | unsigned target; |
| 1773 | int i; |
| 1774 | int nid; |
| 1775 | |
| 1776 | if (!nnodes) |
| 1777 | return numa_node_id(); |
| 1778 | target = (unsigned int)n % nnodes; |
| 1779 | nid = first_node(pol->v.nodes); |
| 1780 | for (i = 0; i < target; i++) |
| 1781 | nid = next_node(nid, pol->v.nodes); |
| 1782 | return nid; |
| 1783 | } |
| 1784 | |
| 1785 | /* Determine a node number for interleave */ |
| 1786 | static inline unsigned interleave_nid(struct mempolicy *pol, |
| 1787 | struct vm_area_struct *vma, unsigned long addr, int shift) |
| 1788 | { |
| 1789 | if (vma) { |
| 1790 | unsigned long off; |
| 1791 | |
| 1792 | /* |
| 1793 | * for small pages, there is no difference between |
| 1794 | * shift and PAGE_SHIFT, so the bit-shift is safe. |
| 1795 | * for huge pages, since vm_pgoff is in units of small |
| 1796 | * pages, we need to shift off the always 0 bits to get |
| 1797 | * a useful offset. |
| 1798 | */ |
| 1799 | BUG_ON(shift < PAGE_SHIFT); |
| 1800 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); |
| 1801 | off += (addr - vma->vm_start) >> shift; |
| 1802 | return offset_il_node(pol, vma, off); |
| 1803 | } else |
| 1804 | return interleave_nodes(pol); |
| 1805 | } |
| 1806 | |
| 1807 | #ifdef CONFIG_HUGETLBFS |
| 1808 | /* |
| 1809 | * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) |
| 1810 | * @vma: virtual memory area whose policy is sought |
| 1811 | * @addr: address in @vma for shared policy lookup and interleave policy |
| 1812 | * @gfp_flags: for requested zone |
| 1813 | * @mpol: pointer to mempolicy pointer for reference counted mempolicy |
| 1814 | * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask |
| 1815 | * |
| 1816 | * Returns a zonelist suitable for a huge page allocation and a pointer |
| 1817 | * to the struct mempolicy for conditional unref after allocation. |
| 1818 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's |
| 1819 | * @nodemask for filtering the zonelist. |
| 1820 | * |
| 1821 | * Must be protected by read_mems_allowed_begin() |
| 1822 | */ |
| 1823 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, |
| 1824 | gfp_t gfp_flags, struct mempolicy **mpol, |
| 1825 | nodemask_t **nodemask) |
| 1826 | { |
| 1827 | struct zonelist *zl; |
| 1828 | |
| 1829 | *mpol = get_vma_policy(vma, addr); |
| 1830 | *nodemask = NULL; /* assume !MPOL_BIND */ |
| 1831 | |
| 1832 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { |
| 1833 | zl = node_zonelist(interleave_nid(*mpol, vma, addr, |
| 1834 | huge_page_shift(hstate_vma(vma))), gfp_flags); |
| 1835 | } else { |
| 1836 | zl = policy_zonelist(gfp_flags, *mpol, numa_node_id()); |
| 1837 | if ((*mpol)->mode == MPOL_BIND) |
| 1838 | *nodemask = &(*mpol)->v.nodes; |
| 1839 | } |
| 1840 | return zl; |
| 1841 | } |
| 1842 | |
| 1843 | /* |
| 1844 | * init_nodemask_of_mempolicy |
| 1845 | * |
| 1846 | * If the current task's mempolicy is "default" [NULL], return 'false' |
| 1847 | * to indicate default policy. Otherwise, extract the policy nodemask |
| 1848 | * for 'bind' or 'interleave' policy into the argument nodemask, or |
| 1849 | * initialize the argument nodemask to contain the single node for |
| 1850 | * 'preferred' or 'local' policy and return 'true' to indicate presence |
| 1851 | * of non-default mempolicy. |
| 1852 | * |
| 1853 | * We don't bother with reference counting the mempolicy [mpol_get/put] |
| 1854 | * because the current task is examining it's own mempolicy and a task's |
| 1855 | * mempolicy is only ever changed by the task itself. |
| 1856 | * |
| 1857 | * N.B., it is the caller's responsibility to free a returned nodemask. |
| 1858 | */ |
| 1859 | bool init_nodemask_of_mempolicy(nodemask_t *mask) |
| 1860 | { |
| 1861 | struct mempolicy *mempolicy; |
| 1862 | int nid; |
| 1863 | |
| 1864 | if (!(mask && current->mempolicy)) |
| 1865 | return false; |
| 1866 | |
| 1867 | task_lock(current); |
| 1868 | mempolicy = current->mempolicy; |
| 1869 | switch (mempolicy->mode) { |
| 1870 | case MPOL_PREFERRED: |
| 1871 | if (mempolicy->flags & MPOL_F_LOCAL) |
| 1872 | nid = numa_node_id(); |
| 1873 | else |
| 1874 | nid = mempolicy->v.preferred_node; |
| 1875 | init_nodemask_of_node(mask, nid); |
| 1876 | break; |
| 1877 | |
| 1878 | case MPOL_BIND: |
| 1879 | /* Fall through */ |
| 1880 | case MPOL_INTERLEAVE: |
| 1881 | *mask = mempolicy->v.nodes; |
| 1882 | break; |
| 1883 | |
| 1884 | default: |
| 1885 | BUG(); |
| 1886 | } |
| 1887 | task_unlock(current); |
| 1888 | |
| 1889 | return true; |
| 1890 | } |
| 1891 | #endif |
| 1892 | |
| 1893 | /* |
| 1894 | * mempolicy_nodemask_intersects |
| 1895 | * |
| 1896 | * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default |
| 1897 | * policy. Otherwise, check for intersection between mask and the policy |
| 1898 | * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' |
| 1899 | * policy, always return true since it may allocate elsewhere on fallback. |
| 1900 | * |
| 1901 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. |
| 1902 | */ |
| 1903 | bool mempolicy_nodemask_intersects(struct task_struct *tsk, |
| 1904 | const nodemask_t *mask) |
| 1905 | { |
| 1906 | struct mempolicy *mempolicy; |
| 1907 | bool ret = true; |
| 1908 | |
| 1909 | if (!mask) |
| 1910 | return ret; |
| 1911 | task_lock(tsk); |
| 1912 | mempolicy = tsk->mempolicy; |
| 1913 | if (!mempolicy) |
| 1914 | goto out; |
| 1915 | |
| 1916 | switch (mempolicy->mode) { |
| 1917 | case MPOL_PREFERRED: |
| 1918 | /* |
| 1919 | * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to |
| 1920 | * allocate from, they may fallback to other nodes when oom. |
| 1921 | * Thus, it's possible for tsk to have allocated memory from |
| 1922 | * nodes in mask. |
| 1923 | */ |
| 1924 | break; |
| 1925 | case MPOL_BIND: |
| 1926 | case MPOL_INTERLEAVE: |
| 1927 | ret = nodes_intersects(mempolicy->v.nodes, *mask); |
| 1928 | break; |
| 1929 | default: |
| 1930 | BUG(); |
| 1931 | } |
| 1932 | out: |
| 1933 | task_unlock(tsk); |
| 1934 | return ret; |
| 1935 | } |
| 1936 | |
| 1937 | /* Allocate a page in interleaved policy. |
| 1938 | Own path because it needs to do special accounting. */ |
| 1939 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, |
| 1940 | unsigned nid) |
| 1941 | { |
| 1942 | struct zonelist *zl; |
| 1943 | struct page *page; |
| 1944 | |
| 1945 | zl = node_zonelist(nid, gfp); |
| 1946 | page = __alloc_pages(gfp, order, zl); |
| 1947 | if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) |
| 1948 | inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); |
| 1949 | return page; |
| 1950 | } |
| 1951 | |
| 1952 | /** |
| 1953 | * alloc_pages_vma - Allocate a page for a VMA. |
| 1954 | * |
| 1955 | * @gfp: |
| 1956 | * %GFP_USER user allocation. |
| 1957 | * %GFP_KERNEL kernel allocations, |
| 1958 | * %GFP_HIGHMEM highmem/user allocations, |
| 1959 | * %GFP_FS allocation should not call back into a file system. |
| 1960 | * %GFP_ATOMIC don't sleep. |
| 1961 | * |
| 1962 | * @order:Order of the GFP allocation. |
| 1963 | * @vma: Pointer to VMA or NULL if not available. |
| 1964 | * @addr: Virtual Address of the allocation. Must be inside the VMA. |
| 1965 | * @node: Which node to prefer for allocation (modulo policy). |
| 1966 | * @hugepage: for hugepages try only the preferred node if possible |
| 1967 | * |
| 1968 | * This function allocates a page from the kernel page pool and applies |
| 1969 | * a NUMA policy associated with the VMA or the current process. |
| 1970 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the |
| 1971 | * mm_struct of the VMA to prevent it from going away. Should be used for |
| 1972 | * all allocations for pages that will be mapped into user space. Returns |
| 1973 | * NULL when no page can be allocated. |
| 1974 | */ |
| 1975 | struct page * |
| 1976 | alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, |
| 1977 | unsigned long addr, int node, bool hugepage) |
| 1978 | { |
| 1979 | struct mempolicy *pol; |
| 1980 | struct page *page; |
| 1981 | unsigned int cpuset_mems_cookie; |
| 1982 | struct zonelist *zl; |
| 1983 | nodemask_t *nmask; |
| 1984 | |
| 1985 | retry_cpuset: |
| 1986 | pol = get_vma_policy(vma, addr); |
| 1987 | cpuset_mems_cookie = read_mems_allowed_begin(); |
| 1988 | |
| 1989 | if (pol->mode == MPOL_INTERLEAVE) { |
| 1990 | unsigned nid; |
| 1991 | |
| 1992 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order); |
| 1993 | mpol_cond_put(pol); |
| 1994 | page = alloc_page_interleave(gfp, order, nid); |
| 1995 | goto out; |
| 1996 | } |
| 1997 | |
| 1998 | if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) { |
| 1999 | int hpage_node = node; |
| 2000 | |
| 2001 | /* |
| 2002 | * For hugepage allocation and non-interleave policy which |
| 2003 | * allows the current node (or other explicitly preferred |
| 2004 | * node) we only try to allocate from the current/preferred |
| 2005 | * node and don't fall back to other nodes, as the cost of |
| 2006 | * remote accesses would likely offset THP benefits. |
| 2007 | * |
| 2008 | * If the policy is interleave, or does not allow the current |
| 2009 | * node in its nodemask, we allocate the standard way. |
| 2010 | */ |
| 2011 | if (pol->mode == MPOL_PREFERRED && |
| 2012 | !(pol->flags & MPOL_F_LOCAL)) |
| 2013 | hpage_node = pol->v.preferred_node; |
| 2014 | |
| 2015 | nmask = policy_nodemask(gfp, pol); |
| 2016 | if (!nmask || node_isset(hpage_node, *nmask)) { |
| 2017 | mpol_cond_put(pol); |
| 2018 | page = __alloc_pages_node(hpage_node, |
| 2019 | gfp | __GFP_THISNODE, order); |
| 2020 | goto out; |
| 2021 | } |
| 2022 | } |
| 2023 | |
| 2024 | nmask = policy_nodemask(gfp, pol); |
| 2025 | zl = policy_zonelist(gfp, pol, node); |
| 2026 | mpol_cond_put(pol); |
| 2027 | page = __alloc_pages_nodemask(gfp, order, zl, nmask); |
| 2028 | out: |
| 2029 | if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) |
| 2030 | goto retry_cpuset; |
| 2031 | return page; |
| 2032 | } |
| 2033 | |
| 2034 | /** |
| 2035 | * alloc_pages_current - Allocate pages. |
| 2036 | * |
| 2037 | * @gfp: |
| 2038 | * %GFP_USER user allocation, |
| 2039 | * %GFP_KERNEL kernel allocation, |
| 2040 | * %GFP_HIGHMEM highmem allocation, |
| 2041 | * %GFP_FS don't call back into a file system. |
| 2042 | * %GFP_ATOMIC don't sleep. |
| 2043 | * @order: Power of two of allocation size in pages. 0 is a single page. |
| 2044 | * |
| 2045 | * Allocate a page from the kernel page pool. When not in |
| 2046 | * interrupt context and apply the current process NUMA policy. |
| 2047 | * Returns NULL when no page can be allocated. |
| 2048 | * |
| 2049 | * Don't call cpuset_update_task_memory_state() unless |
| 2050 | * 1) it's ok to take cpuset_sem (can WAIT), and |
| 2051 | * 2) allocating for current task (not interrupt). |
| 2052 | */ |
| 2053 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) |
| 2054 | { |
| 2055 | struct mempolicy *pol = &default_policy; |
| 2056 | struct page *page; |
| 2057 | unsigned int cpuset_mems_cookie; |
| 2058 | |
| 2059 | if (!in_interrupt() && !(gfp & __GFP_THISNODE)) |
| 2060 | pol = get_task_policy(current); |
| 2061 | |
| 2062 | retry_cpuset: |
| 2063 | cpuset_mems_cookie = read_mems_allowed_begin(); |
| 2064 | |
| 2065 | /* |
| 2066 | * No reference counting needed for current->mempolicy |
| 2067 | * nor system default_policy |
| 2068 | */ |
| 2069 | if (pol->mode == MPOL_INTERLEAVE) |
| 2070 | page = alloc_page_interleave(gfp, order, interleave_nodes(pol)); |
| 2071 | else |
| 2072 | page = __alloc_pages_nodemask(gfp, order, |
| 2073 | policy_zonelist(gfp, pol, numa_node_id()), |
| 2074 | policy_nodemask(gfp, pol)); |
| 2075 | |
| 2076 | if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) |
| 2077 | goto retry_cpuset; |
| 2078 | |
| 2079 | return page; |
| 2080 | } |
| 2081 | EXPORT_SYMBOL(alloc_pages_current); |
| 2082 | |
| 2083 | int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) |
| 2084 | { |
| 2085 | struct mempolicy *pol = mpol_dup(vma_policy(src)); |
| 2086 | |
| 2087 | if (IS_ERR(pol)) |
| 2088 | return PTR_ERR(pol); |
| 2089 | dst->vm_policy = pol; |
| 2090 | return 0; |
| 2091 | } |
| 2092 | |
| 2093 | /* |
| 2094 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it |
| 2095 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() |
| 2096 | * with the mems_allowed returned by cpuset_mems_allowed(). This |
| 2097 | * keeps mempolicies cpuset relative after its cpuset moves. See |
| 2098 | * further kernel/cpuset.c update_nodemask(). |
| 2099 | * |
| 2100 | * current's mempolicy may be rebinded by the other task(the task that changes |
| 2101 | * cpuset's mems), so we needn't do rebind work for current task. |
| 2102 | */ |
| 2103 | |
| 2104 | /* Slow path of a mempolicy duplicate */ |
| 2105 | struct mempolicy *__mpol_dup(struct mempolicy *old) |
| 2106 | { |
| 2107 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 2108 | |
| 2109 | if (!new) |
| 2110 | return ERR_PTR(-ENOMEM); |
| 2111 | |
| 2112 | /* task's mempolicy is protected by alloc_lock */ |
| 2113 | if (old == current->mempolicy) { |
| 2114 | task_lock(current); |
| 2115 | *new = *old; |
| 2116 | task_unlock(current); |
| 2117 | } else |
| 2118 | *new = *old; |
| 2119 | |
| 2120 | if (current_cpuset_is_being_rebound()) { |
| 2121 | nodemask_t mems = cpuset_mems_allowed(current); |
| 2122 | if (new->flags & MPOL_F_REBINDING) |
| 2123 | mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2); |
| 2124 | else |
| 2125 | mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); |
| 2126 | } |
| 2127 | atomic_set(&new->refcnt, 1); |
| 2128 | return new; |
| 2129 | } |
| 2130 | |
| 2131 | /* Slow path of a mempolicy comparison */ |
| 2132 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) |
| 2133 | { |
| 2134 | if (!a || !b) |
| 2135 | return false; |
| 2136 | if (a->mode != b->mode) |
| 2137 | return false; |
| 2138 | if (a->flags != b->flags) |
| 2139 | return false; |
| 2140 | if (mpol_store_user_nodemask(a)) |
| 2141 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) |
| 2142 | return false; |
| 2143 | |
| 2144 | switch (a->mode) { |
| 2145 | case MPOL_BIND: |
| 2146 | /* Fall through */ |
| 2147 | case MPOL_INTERLEAVE: |
| 2148 | return !!nodes_equal(a->v.nodes, b->v.nodes); |
| 2149 | case MPOL_PREFERRED: |
| 2150 | return a->v.preferred_node == b->v.preferred_node; |
| 2151 | default: |
| 2152 | BUG(); |
| 2153 | return false; |
| 2154 | } |
| 2155 | } |
| 2156 | |
| 2157 | /* |
| 2158 | * Shared memory backing store policy support. |
| 2159 | * |
| 2160 | * Remember policies even when nobody has shared memory mapped. |
| 2161 | * The policies are kept in Red-Black tree linked from the inode. |
| 2162 | * They are protected by the sp->lock rwlock, which should be held |
| 2163 | * for any accesses to the tree. |
| 2164 | */ |
| 2165 | |
| 2166 | /* |
| 2167 | * lookup first element intersecting start-end. Caller holds sp->lock for |
| 2168 | * reading or for writing |
| 2169 | */ |
| 2170 | static struct sp_node * |
| 2171 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) |
| 2172 | { |
| 2173 | struct rb_node *n = sp->root.rb_node; |
| 2174 | |
| 2175 | while (n) { |
| 2176 | struct sp_node *p = rb_entry(n, struct sp_node, nd); |
| 2177 | |
| 2178 | if (start >= p->end) |
| 2179 | n = n->rb_right; |
| 2180 | else if (end <= p->start) |
| 2181 | n = n->rb_left; |
| 2182 | else |
| 2183 | break; |
| 2184 | } |
| 2185 | if (!n) |
| 2186 | return NULL; |
| 2187 | for (;;) { |
| 2188 | struct sp_node *w = NULL; |
| 2189 | struct rb_node *prev = rb_prev(n); |
| 2190 | if (!prev) |
| 2191 | break; |
| 2192 | w = rb_entry(prev, struct sp_node, nd); |
| 2193 | if (w->end <= start) |
| 2194 | break; |
| 2195 | n = prev; |
| 2196 | } |
| 2197 | return rb_entry(n, struct sp_node, nd); |
| 2198 | } |
| 2199 | |
| 2200 | /* |
| 2201 | * Insert a new shared policy into the list. Caller holds sp->lock for |
| 2202 | * writing. |
| 2203 | */ |
| 2204 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) |
| 2205 | { |
| 2206 | struct rb_node **p = &sp->root.rb_node; |
| 2207 | struct rb_node *parent = NULL; |
| 2208 | struct sp_node *nd; |
| 2209 | |
| 2210 | while (*p) { |
| 2211 | parent = *p; |
| 2212 | nd = rb_entry(parent, struct sp_node, nd); |
| 2213 | if (new->start < nd->start) |
| 2214 | p = &(*p)->rb_left; |
| 2215 | else if (new->end > nd->end) |
| 2216 | p = &(*p)->rb_right; |
| 2217 | else |
| 2218 | BUG(); |
| 2219 | } |
| 2220 | rb_link_node(&new->nd, parent, p); |
| 2221 | rb_insert_color(&new->nd, &sp->root); |
| 2222 | pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, |
| 2223 | new->policy ? new->policy->mode : 0); |
| 2224 | } |
| 2225 | |
| 2226 | /* Find shared policy intersecting idx */ |
| 2227 | struct mempolicy * |
| 2228 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) |
| 2229 | { |
| 2230 | struct mempolicy *pol = NULL; |
| 2231 | struct sp_node *sn; |
| 2232 | |
| 2233 | if (!sp->root.rb_node) |
| 2234 | return NULL; |
| 2235 | read_lock(&sp->lock); |
| 2236 | sn = sp_lookup(sp, idx, idx+1); |
| 2237 | if (sn) { |
| 2238 | mpol_get(sn->policy); |
| 2239 | pol = sn->policy; |
| 2240 | } |
| 2241 | read_unlock(&sp->lock); |
| 2242 | return pol; |
| 2243 | } |
| 2244 | |
| 2245 | static void sp_free(struct sp_node *n) |
| 2246 | { |
| 2247 | mpol_put(n->policy); |
| 2248 | kmem_cache_free(sn_cache, n); |
| 2249 | } |
| 2250 | |
| 2251 | /** |
| 2252 | * mpol_misplaced - check whether current page node is valid in policy |
| 2253 | * |
| 2254 | * @page: page to be checked |
| 2255 | * @vma: vm area where page mapped |
| 2256 | * @addr: virtual address where page mapped |
| 2257 | * |
| 2258 | * Lookup current policy node id for vma,addr and "compare to" page's |
| 2259 | * node id. |
| 2260 | * |
| 2261 | * Returns: |
| 2262 | * -1 - not misplaced, page is in the right node |
| 2263 | * node - node id where the page should be |
| 2264 | * |
| 2265 | * Policy determination "mimics" alloc_page_vma(). |
| 2266 | * Called from fault path where we know the vma and faulting address. |
| 2267 | */ |
| 2268 | int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr) |
| 2269 | { |
| 2270 | struct mempolicy *pol; |
| 2271 | struct zoneref *z; |
| 2272 | int curnid = page_to_nid(page); |
| 2273 | unsigned long pgoff; |
| 2274 | int thiscpu = raw_smp_processor_id(); |
| 2275 | int thisnid = cpu_to_node(thiscpu); |
| 2276 | int polnid = -1; |
| 2277 | int ret = -1; |
| 2278 | |
| 2279 | BUG_ON(!vma); |
| 2280 | |
| 2281 | pol = get_vma_policy(vma, addr); |
| 2282 | if (!(pol->flags & MPOL_F_MOF)) |
| 2283 | goto out; |
| 2284 | |
| 2285 | switch (pol->mode) { |
| 2286 | case MPOL_INTERLEAVE: |
| 2287 | BUG_ON(addr >= vma->vm_end); |
| 2288 | BUG_ON(addr < vma->vm_start); |
| 2289 | |
| 2290 | pgoff = vma->vm_pgoff; |
| 2291 | pgoff += (addr - vma->vm_start) >> PAGE_SHIFT; |
| 2292 | polnid = offset_il_node(pol, vma, pgoff); |
| 2293 | break; |
| 2294 | |
| 2295 | case MPOL_PREFERRED: |
| 2296 | if (pol->flags & MPOL_F_LOCAL) |
| 2297 | polnid = numa_node_id(); |
| 2298 | else |
| 2299 | polnid = pol->v.preferred_node; |
| 2300 | break; |
| 2301 | |
| 2302 | case MPOL_BIND: |
| 2303 | |
| 2304 | /* |
| 2305 | * allows binding to multiple nodes. |
| 2306 | * use current page if in policy nodemask, |
| 2307 | * else select nearest allowed node, if any. |
| 2308 | * If no allowed nodes, use current [!misplaced]. |
| 2309 | */ |
| 2310 | if (node_isset(curnid, pol->v.nodes)) |
| 2311 | goto out; |
| 2312 | z = first_zones_zonelist( |
| 2313 | node_zonelist(numa_node_id(), GFP_HIGHUSER), |
| 2314 | gfp_zone(GFP_HIGHUSER), |
| 2315 | &pol->v.nodes); |
| 2316 | polnid = z->zone->node; |
| 2317 | break; |
| 2318 | |
| 2319 | default: |
| 2320 | BUG(); |
| 2321 | } |
| 2322 | |
| 2323 | /* Migrate the page towards the node whose CPU is referencing it */ |
| 2324 | if (pol->flags & MPOL_F_MORON) { |
| 2325 | polnid = thisnid; |
| 2326 | |
| 2327 | if (!should_numa_migrate_memory(current, page, curnid, thiscpu)) |
| 2328 | goto out; |
| 2329 | } |
| 2330 | |
| 2331 | if (curnid != polnid) |
| 2332 | ret = polnid; |
| 2333 | out: |
| 2334 | mpol_cond_put(pol); |
| 2335 | |
| 2336 | return ret; |
| 2337 | } |
| 2338 | |
| 2339 | /* |
| 2340 | * Drop the (possibly final) reference to task->mempolicy. It needs to be |
| 2341 | * dropped after task->mempolicy is set to NULL so that any allocation done as |
| 2342 | * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed |
| 2343 | * policy. |
| 2344 | */ |
| 2345 | void mpol_put_task_policy(struct task_struct *task) |
| 2346 | { |
| 2347 | struct mempolicy *pol; |
| 2348 | |
| 2349 | task_lock(task); |
| 2350 | pol = task->mempolicy; |
| 2351 | task->mempolicy = NULL; |
| 2352 | task_unlock(task); |
| 2353 | mpol_put(pol); |
| 2354 | } |
| 2355 | |
| 2356 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) |
| 2357 | { |
| 2358 | pr_debug("deleting %lx-l%lx\n", n->start, n->end); |
| 2359 | rb_erase(&n->nd, &sp->root); |
| 2360 | sp_free(n); |
| 2361 | } |
| 2362 | |
| 2363 | static void sp_node_init(struct sp_node *node, unsigned long start, |
| 2364 | unsigned long end, struct mempolicy *pol) |
| 2365 | { |
| 2366 | node->start = start; |
| 2367 | node->end = end; |
| 2368 | node->policy = pol; |
| 2369 | } |
| 2370 | |
| 2371 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, |
| 2372 | struct mempolicy *pol) |
| 2373 | { |
| 2374 | struct sp_node *n; |
| 2375 | struct mempolicy *newpol; |
| 2376 | |
| 2377 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
| 2378 | if (!n) |
| 2379 | return NULL; |
| 2380 | |
| 2381 | newpol = mpol_dup(pol); |
| 2382 | if (IS_ERR(newpol)) { |
| 2383 | kmem_cache_free(sn_cache, n); |
| 2384 | return NULL; |
| 2385 | } |
| 2386 | newpol->flags |= MPOL_F_SHARED; |
| 2387 | sp_node_init(n, start, end, newpol); |
| 2388 | |
| 2389 | return n; |
| 2390 | } |
| 2391 | |
| 2392 | /* Replace a policy range. */ |
| 2393 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, |
| 2394 | unsigned long end, struct sp_node *new) |
| 2395 | { |
| 2396 | struct sp_node *n; |
| 2397 | struct sp_node *n_new = NULL; |
| 2398 | struct mempolicy *mpol_new = NULL; |
| 2399 | int ret = 0; |
| 2400 | |
| 2401 | restart: |
| 2402 | write_lock(&sp->lock); |
| 2403 | n = sp_lookup(sp, start, end); |
| 2404 | /* Take care of old policies in the same range. */ |
| 2405 | while (n && n->start < end) { |
| 2406 | struct rb_node *next = rb_next(&n->nd); |
| 2407 | if (n->start >= start) { |
| 2408 | if (n->end <= end) |
| 2409 | sp_delete(sp, n); |
| 2410 | else |
| 2411 | n->start = end; |
| 2412 | } else { |
| 2413 | /* Old policy spanning whole new range. */ |
| 2414 | if (n->end > end) { |
| 2415 | if (!n_new) |
| 2416 | goto alloc_new; |
| 2417 | |
| 2418 | *mpol_new = *n->policy; |
| 2419 | atomic_set(&mpol_new->refcnt, 1); |
| 2420 | sp_node_init(n_new, end, n->end, mpol_new); |
| 2421 | n->end = start; |
| 2422 | sp_insert(sp, n_new); |
| 2423 | n_new = NULL; |
| 2424 | mpol_new = NULL; |
| 2425 | break; |
| 2426 | } else |
| 2427 | n->end = start; |
| 2428 | } |
| 2429 | if (!next) |
| 2430 | break; |
| 2431 | n = rb_entry(next, struct sp_node, nd); |
| 2432 | } |
| 2433 | if (new) |
| 2434 | sp_insert(sp, new); |
| 2435 | write_unlock(&sp->lock); |
| 2436 | ret = 0; |
| 2437 | |
| 2438 | err_out: |
| 2439 | if (mpol_new) |
| 2440 | mpol_put(mpol_new); |
| 2441 | if (n_new) |
| 2442 | kmem_cache_free(sn_cache, n_new); |
| 2443 | |
| 2444 | return ret; |
| 2445 | |
| 2446 | alloc_new: |
| 2447 | write_unlock(&sp->lock); |
| 2448 | ret = -ENOMEM; |
| 2449 | n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
| 2450 | if (!n_new) |
| 2451 | goto err_out; |
| 2452 | mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 2453 | if (!mpol_new) |
| 2454 | goto err_out; |
| 2455 | goto restart; |
| 2456 | } |
| 2457 | |
| 2458 | /** |
| 2459 | * mpol_shared_policy_init - initialize shared policy for inode |
| 2460 | * @sp: pointer to inode shared policy |
| 2461 | * @mpol: struct mempolicy to install |
| 2462 | * |
| 2463 | * Install non-NULL @mpol in inode's shared policy rb-tree. |
| 2464 | * On entry, the current task has a reference on a non-NULL @mpol. |
| 2465 | * This must be released on exit. |
| 2466 | * This is called at get_inode() calls and we can use GFP_KERNEL. |
| 2467 | */ |
| 2468 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) |
| 2469 | { |
| 2470 | int ret; |
| 2471 | |
| 2472 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ |
| 2473 | rwlock_init(&sp->lock); |
| 2474 | |
| 2475 | if (mpol) { |
| 2476 | struct vm_area_struct pvma; |
| 2477 | struct mempolicy *new; |
| 2478 | NODEMASK_SCRATCH(scratch); |
| 2479 | |
| 2480 | if (!scratch) |
| 2481 | goto put_mpol; |
| 2482 | /* contextualize the tmpfs mount point mempolicy */ |
| 2483 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); |
| 2484 | if (IS_ERR(new)) |
| 2485 | goto free_scratch; /* no valid nodemask intersection */ |
| 2486 | |
| 2487 | task_lock(current); |
| 2488 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); |
| 2489 | task_unlock(current); |
| 2490 | if (ret) |
| 2491 | goto put_new; |
| 2492 | |
| 2493 | /* Create pseudo-vma that contains just the policy */ |
| 2494 | memset(&pvma, 0, sizeof(struct vm_area_struct)); |
| 2495 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ |
| 2496 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ |
| 2497 | |
| 2498 | put_new: |
| 2499 | mpol_put(new); /* drop initial ref */ |
| 2500 | free_scratch: |
| 2501 | NODEMASK_SCRATCH_FREE(scratch); |
| 2502 | put_mpol: |
| 2503 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ |
| 2504 | } |
| 2505 | } |
| 2506 | |
| 2507 | int mpol_set_shared_policy(struct shared_policy *info, |
| 2508 | struct vm_area_struct *vma, struct mempolicy *npol) |
| 2509 | { |
| 2510 | int err; |
| 2511 | struct sp_node *new = NULL; |
| 2512 | unsigned long sz = vma_pages(vma); |
| 2513 | |
| 2514 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", |
| 2515 | vma->vm_pgoff, |
| 2516 | sz, npol ? npol->mode : -1, |
| 2517 | npol ? npol->flags : -1, |
| 2518 | npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE); |
| 2519 | |
| 2520 | if (npol) { |
| 2521 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); |
| 2522 | if (!new) |
| 2523 | return -ENOMEM; |
| 2524 | } |
| 2525 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); |
| 2526 | if (err && new) |
| 2527 | sp_free(new); |
| 2528 | return err; |
| 2529 | } |
| 2530 | |
| 2531 | /* Free a backing policy store on inode delete. */ |
| 2532 | void mpol_free_shared_policy(struct shared_policy *p) |
| 2533 | { |
| 2534 | struct sp_node *n; |
| 2535 | struct rb_node *next; |
| 2536 | |
| 2537 | if (!p->root.rb_node) |
| 2538 | return; |
| 2539 | write_lock(&p->lock); |
| 2540 | next = rb_first(&p->root); |
| 2541 | while (next) { |
| 2542 | n = rb_entry(next, struct sp_node, nd); |
| 2543 | next = rb_next(&n->nd); |
| 2544 | sp_delete(p, n); |
| 2545 | } |
| 2546 | write_unlock(&p->lock); |
| 2547 | } |
| 2548 | |
| 2549 | #ifdef CONFIG_NUMA_BALANCING |
| 2550 | static int __initdata numabalancing_override; |
| 2551 | |
| 2552 | static void __init check_numabalancing_enable(void) |
| 2553 | { |
| 2554 | bool numabalancing_default = false; |
| 2555 | |
| 2556 | if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED)) |
| 2557 | numabalancing_default = true; |
| 2558 | |
| 2559 | /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */ |
| 2560 | if (numabalancing_override) |
| 2561 | set_numabalancing_state(numabalancing_override == 1); |
| 2562 | |
| 2563 | if (num_online_nodes() > 1 && !numabalancing_override) { |
| 2564 | pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n", |
| 2565 | numabalancing_default ? "Enabling" : "Disabling"); |
| 2566 | set_numabalancing_state(numabalancing_default); |
| 2567 | } |
| 2568 | } |
| 2569 | |
| 2570 | static int __init setup_numabalancing(char *str) |
| 2571 | { |
| 2572 | int ret = 0; |
| 2573 | if (!str) |
| 2574 | goto out; |
| 2575 | |
| 2576 | if (!strcmp(str, "enable")) { |
| 2577 | numabalancing_override = 1; |
| 2578 | ret = 1; |
| 2579 | } else if (!strcmp(str, "disable")) { |
| 2580 | numabalancing_override = -1; |
| 2581 | ret = 1; |
| 2582 | } |
| 2583 | out: |
| 2584 | if (!ret) |
| 2585 | pr_warn("Unable to parse numa_balancing=\n"); |
| 2586 | |
| 2587 | return ret; |
| 2588 | } |
| 2589 | __setup("numa_balancing=", setup_numabalancing); |
| 2590 | #else |
| 2591 | static inline void __init check_numabalancing_enable(void) |
| 2592 | { |
| 2593 | } |
| 2594 | #endif /* CONFIG_NUMA_BALANCING */ |
| 2595 | |
| 2596 | /* assumes fs == KERNEL_DS */ |
| 2597 | void __init numa_policy_init(void) |
| 2598 | { |
| 2599 | nodemask_t interleave_nodes; |
| 2600 | unsigned long largest = 0; |
| 2601 | int nid, prefer = 0; |
| 2602 | |
| 2603 | policy_cache = kmem_cache_create("numa_policy", |
| 2604 | sizeof(struct mempolicy), |
| 2605 | 0, SLAB_PANIC, NULL); |
| 2606 | |
| 2607 | sn_cache = kmem_cache_create("shared_policy_node", |
| 2608 | sizeof(struct sp_node), |
| 2609 | 0, SLAB_PANIC, NULL); |
| 2610 | |
| 2611 | for_each_node(nid) { |
| 2612 | preferred_node_policy[nid] = (struct mempolicy) { |
| 2613 | .refcnt = ATOMIC_INIT(1), |
| 2614 | .mode = MPOL_PREFERRED, |
| 2615 | .flags = MPOL_F_MOF | MPOL_F_MORON, |
| 2616 | .v = { .preferred_node = nid, }, |
| 2617 | }; |
| 2618 | } |
| 2619 | |
| 2620 | /* |
| 2621 | * Set interleaving policy for system init. Interleaving is only |
| 2622 | * enabled across suitably sized nodes (default is >= 16MB), or |
| 2623 | * fall back to the largest node if they're all smaller. |
| 2624 | */ |
| 2625 | nodes_clear(interleave_nodes); |
| 2626 | for_each_node_state(nid, N_MEMORY) { |
| 2627 | unsigned long total_pages = node_present_pages(nid); |
| 2628 | |
| 2629 | /* Preserve the largest node */ |
| 2630 | if (largest < total_pages) { |
| 2631 | largest = total_pages; |
| 2632 | prefer = nid; |
| 2633 | } |
| 2634 | |
| 2635 | /* Interleave this node? */ |
| 2636 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) |
| 2637 | node_set(nid, interleave_nodes); |
| 2638 | } |
| 2639 | |
| 2640 | /* All too small, use the largest */ |
| 2641 | if (unlikely(nodes_empty(interleave_nodes))) |
| 2642 | node_set(prefer, interleave_nodes); |
| 2643 | |
| 2644 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) |
| 2645 | pr_err("%s: interleaving failed\n", __func__); |
| 2646 | |
| 2647 | check_numabalancing_enable(); |
| 2648 | } |
| 2649 | |
| 2650 | /* Reset policy of current process to default */ |
| 2651 | void numa_default_policy(void) |
| 2652 | { |
| 2653 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); |
| 2654 | } |
| 2655 | |
| 2656 | /* |
| 2657 | * Parse and format mempolicy from/to strings |
| 2658 | */ |
| 2659 | |
| 2660 | /* |
| 2661 | * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag. |
| 2662 | */ |
| 2663 | static const char * const policy_modes[] = |
| 2664 | { |
| 2665 | [MPOL_DEFAULT] = "default", |
| 2666 | [MPOL_PREFERRED] = "prefer", |
| 2667 | [MPOL_BIND] = "bind", |
| 2668 | [MPOL_INTERLEAVE] = "interleave", |
| 2669 | [MPOL_LOCAL] = "local", |
| 2670 | }; |
| 2671 | |
| 2672 | |
| 2673 | #ifdef CONFIG_TMPFS |
| 2674 | /** |
| 2675 | * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option. |
| 2676 | * @str: string containing mempolicy to parse |
| 2677 | * @mpol: pointer to struct mempolicy pointer, returned on success. |
| 2678 | * |
| 2679 | * Format of input: |
| 2680 | * <mode>[=<flags>][:<nodelist>] |
| 2681 | * |
| 2682 | * On success, returns 0, else 1 |
| 2683 | */ |
| 2684 | int mpol_parse_str(char *str, struct mempolicy **mpol) |
| 2685 | { |
| 2686 | struct mempolicy *new = NULL; |
| 2687 | unsigned short mode; |
| 2688 | unsigned short mode_flags; |
| 2689 | nodemask_t nodes; |
| 2690 | char *nodelist = strchr(str, ':'); |
| 2691 | char *flags = strchr(str, '='); |
| 2692 | int err = 1; |
| 2693 | |
| 2694 | if (nodelist) { |
| 2695 | /* NUL-terminate mode or flags string */ |
| 2696 | *nodelist++ = '\0'; |
| 2697 | if (nodelist_parse(nodelist, nodes)) |
| 2698 | goto out; |
| 2699 | if (!nodes_subset(nodes, node_states[N_MEMORY])) |
| 2700 | goto out; |
| 2701 | } else |
| 2702 | nodes_clear(nodes); |
| 2703 | |
| 2704 | if (flags) |
| 2705 | *flags++ = '\0'; /* terminate mode string */ |
| 2706 | |
| 2707 | for (mode = 0; mode < MPOL_MAX; mode++) { |
| 2708 | if (!strcmp(str, policy_modes[mode])) { |
| 2709 | break; |
| 2710 | } |
| 2711 | } |
| 2712 | if (mode >= MPOL_MAX) |
| 2713 | goto out; |
| 2714 | |
| 2715 | switch (mode) { |
| 2716 | case MPOL_PREFERRED: |
| 2717 | /* |
| 2718 | * Insist on a nodelist of one node only |
| 2719 | */ |
| 2720 | if (nodelist) { |
| 2721 | char *rest = nodelist; |
| 2722 | while (isdigit(*rest)) |
| 2723 | rest++; |
| 2724 | if (*rest) |
| 2725 | goto out; |
| 2726 | } |
| 2727 | break; |
| 2728 | case MPOL_INTERLEAVE: |
| 2729 | /* |
| 2730 | * Default to online nodes with memory if no nodelist |
| 2731 | */ |
| 2732 | if (!nodelist) |
| 2733 | nodes = node_states[N_MEMORY]; |
| 2734 | break; |
| 2735 | case MPOL_LOCAL: |
| 2736 | /* |
| 2737 | * Don't allow a nodelist; mpol_new() checks flags |
| 2738 | */ |
| 2739 | if (nodelist) |
| 2740 | goto out; |
| 2741 | mode = MPOL_PREFERRED; |
| 2742 | break; |
| 2743 | case MPOL_DEFAULT: |
| 2744 | /* |
| 2745 | * Insist on a empty nodelist |
| 2746 | */ |
| 2747 | if (!nodelist) |
| 2748 | err = 0; |
| 2749 | goto out; |
| 2750 | case MPOL_BIND: |
| 2751 | /* |
| 2752 | * Insist on a nodelist |
| 2753 | */ |
| 2754 | if (!nodelist) |
| 2755 | goto out; |
| 2756 | } |
| 2757 | |
| 2758 | mode_flags = 0; |
| 2759 | if (flags) { |
| 2760 | /* |
| 2761 | * Currently, we only support two mutually exclusive |
| 2762 | * mode flags. |
| 2763 | */ |
| 2764 | if (!strcmp(flags, "static")) |
| 2765 | mode_flags |= MPOL_F_STATIC_NODES; |
| 2766 | else if (!strcmp(flags, "relative")) |
| 2767 | mode_flags |= MPOL_F_RELATIVE_NODES; |
| 2768 | else |
| 2769 | goto out; |
| 2770 | } |
| 2771 | |
| 2772 | new = mpol_new(mode, mode_flags, &nodes); |
| 2773 | if (IS_ERR(new)) |
| 2774 | goto out; |
| 2775 | |
| 2776 | /* |
| 2777 | * Save nodes for mpol_to_str() to show the tmpfs mount options |
| 2778 | * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo. |
| 2779 | */ |
| 2780 | if (mode != MPOL_PREFERRED) |
| 2781 | new->v.nodes = nodes; |
| 2782 | else if (nodelist) |
| 2783 | new->v.preferred_node = first_node(nodes); |
| 2784 | else |
| 2785 | new->flags |= MPOL_F_LOCAL; |
| 2786 | |
| 2787 | /* |
| 2788 | * Save nodes for contextualization: this will be used to "clone" |
| 2789 | * the mempolicy in a specific context [cpuset] at a later time. |
| 2790 | */ |
| 2791 | new->w.user_nodemask = nodes; |
| 2792 | |
| 2793 | err = 0; |
| 2794 | |
| 2795 | out: |
| 2796 | /* Restore string for error message */ |
| 2797 | if (nodelist) |
| 2798 | *--nodelist = ':'; |
| 2799 | if (flags) |
| 2800 | *--flags = '='; |
| 2801 | if (!err) |
| 2802 | *mpol = new; |
| 2803 | return err; |
| 2804 | } |
| 2805 | #endif /* CONFIG_TMPFS */ |
| 2806 | |
| 2807 | /** |
| 2808 | * mpol_to_str - format a mempolicy structure for printing |
| 2809 | * @buffer: to contain formatted mempolicy string |
| 2810 | * @maxlen: length of @buffer |
| 2811 | * @pol: pointer to mempolicy to be formatted |
| 2812 | * |
| 2813 | * Convert @pol into a string. If @buffer is too short, truncate the string. |
| 2814 | * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the |
| 2815 | * longest flag, "relative", and to display at least a few node ids. |
| 2816 | */ |
| 2817 | void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) |
| 2818 | { |
| 2819 | char *p = buffer; |
| 2820 | nodemask_t nodes = NODE_MASK_NONE; |
| 2821 | unsigned short mode = MPOL_DEFAULT; |
| 2822 | unsigned short flags = 0; |
| 2823 | |
| 2824 | if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) { |
| 2825 | mode = pol->mode; |
| 2826 | flags = pol->flags; |
| 2827 | } |
| 2828 | |
| 2829 | switch (mode) { |
| 2830 | case MPOL_DEFAULT: |
| 2831 | break; |
| 2832 | case MPOL_PREFERRED: |
| 2833 | if (flags & MPOL_F_LOCAL) |
| 2834 | mode = MPOL_LOCAL; |
| 2835 | else |
| 2836 | node_set(pol->v.preferred_node, nodes); |
| 2837 | break; |
| 2838 | case MPOL_BIND: |
| 2839 | case MPOL_INTERLEAVE: |
| 2840 | nodes = pol->v.nodes; |
| 2841 | break; |
| 2842 | default: |
| 2843 | WARN_ON_ONCE(1); |
| 2844 | snprintf(p, maxlen, "unknown"); |
| 2845 | return; |
| 2846 | } |
| 2847 | |
| 2848 | p += snprintf(p, maxlen, "%s", policy_modes[mode]); |
| 2849 | |
| 2850 | if (flags & MPOL_MODE_FLAGS) { |
| 2851 | p += snprintf(p, buffer + maxlen - p, "="); |
| 2852 | |
| 2853 | /* |
| 2854 | * Currently, the only defined flags are mutually exclusive |
| 2855 | */ |
| 2856 | if (flags & MPOL_F_STATIC_NODES) |
| 2857 | p += snprintf(p, buffer + maxlen - p, "static"); |
| 2858 | else if (flags & MPOL_F_RELATIVE_NODES) |
| 2859 | p += snprintf(p, buffer + maxlen - p, "relative"); |
| 2860 | } |
| 2861 | |
| 2862 | if (!nodes_empty(nodes)) |
| 2863 | p += scnprintf(p, buffer + maxlen - p, ":%*pbl", |
| 2864 | nodemask_pr_args(&nodes)); |
| 2865 | } |