| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * Simple NUMA memory policy for the Linux kernel. |
| 4 | * |
| 5 | * Copyright 2003,2004 Andi Kleen, SuSE Labs. |
| 6 | * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc. |
| 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 | * weighted interleave |
| 23 | * Allocate memory interleaved over a set of nodes based on |
| 24 | * a set of weights (per-node), with normal fallback if it |
| 25 | * fails. Otherwise operates the same as interleave. |
| 26 | * Example: nodeset(0,1) & weights (2,1) - 2 pages allocated |
| 27 | * on node 0 for every 1 page allocated on node 1. |
| 28 | * |
| 29 | * bind Only allocate memory on a specific set of nodes, |
| 30 | * no fallback. |
| 31 | * FIXME: memory is allocated starting with the first node |
| 32 | * to the last. It would be better if bind would truly restrict |
| 33 | * the allocation to memory nodes instead |
| 34 | * |
| 35 | * preferred Try a specific node first before normal fallback. |
| 36 | * As a special case NUMA_NO_NODE here means do the allocation |
| 37 | * on the local CPU. This is normally identical to default, |
| 38 | * but useful to set in a VMA when you have a non default |
| 39 | * process policy. |
| 40 | * |
| 41 | * preferred many Try a set of nodes first before normal fallback. This is |
| 42 | * similar to preferred without the special case. |
| 43 | * |
| 44 | * default Allocate on the local node first, or when on a VMA |
| 45 | * use the process policy. This is what Linux always did |
| 46 | * in a NUMA aware kernel and still does by, ahem, default. |
| 47 | * |
| 48 | * The process policy is applied for most non interrupt memory allocations |
| 49 | * in that process' context. Interrupts ignore the policies and always |
| 50 | * try to allocate on the local CPU. The VMA policy is only applied for memory |
| 51 | * allocations for a VMA in the VM. |
| 52 | * |
| 53 | * Currently there are a few corner cases in swapping where the policy |
| 54 | * is not applied, but the majority should be handled. When process policy |
| 55 | * is used it is not remembered over swap outs/swap ins. |
| 56 | * |
| 57 | * Only the highest zone in the zone hierarchy gets policied. Allocations |
| 58 | * requesting a lower zone just use default policy. This implies that |
| 59 | * on systems with highmem kernel lowmem allocation don't get policied. |
| 60 | * Same with GFP_DMA allocations. |
| 61 | * |
| 62 | * For shmem/tmpfs shared memory the policy is shared between |
| 63 | * all users and remembered even when nobody has memory mapped. |
| 64 | */ |
| 65 | |
| 66 | /* Notebook: |
| 67 | fix mmap readahead to honour policy and enable policy for any page cache |
| 68 | object |
| 69 | statistics for bigpages |
| 70 | global policy for page cache? currently it uses process policy. Requires |
| 71 | first item above. |
| 72 | handle mremap for shared memory (currently ignored for the policy) |
| 73 | grows down? |
| 74 | make bind policy root only? It can trigger oom much faster and the |
| 75 | kernel is not always grateful with that. |
| 76 | */ |
| 77 | |
| 78 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 79 | |
| 80 | #include <linux/mempolicy.h> |
| 81 | #include <linux/pagewalk.h> |
| 82 | #include <linux/highmem.h> |
| 83 | #include <linux/hugetlb.h> |
| 84 | #include <linux/kernel.h> |
| 85 | #include <linux/sched.h> |
| 86 | #include <linux/sched/mm.h> |
| 87 | #include <linux/sched/numa_balancing.h> |
| 88 | #include <linux/sched/task.h> |
| 89 | #include <linux/nodemask.h> |
| 90 | #include <linux/cpuset.h> |
| 91 | #include <linux/slab.h> |
| 92 | #include <linux/string.h> |
| 93 | #include <linux/export.h> |
| 94 | #include <linux/nsproxy.h> |
| 95 | #include <linux/interrupt.h> |
| 96 | #include <linux/init.h> |
| 97 | #include <linux/compat.h> |
| 98 | #include <linux/ptrace.h> |
| 99 | #include <linux/swap.h> |
| 100 | #include <linux/seq_file.h> |
| 101 | #include <linux/proc_fs.h> |
| 102 | #include <linux/migrate.h> |
| 103 | #include <linux/ksm.h> |
| 104 | #include <linux/rmap.h> |
| 105 | #include <linux/security.h> |
| 106 | #include <linux/syscalls.h> |
| 107 | #include <linux/ctype.h> |
| 108 | #include <linux/mm_inline.h> |
| 109 | #include <linux/mmu_notifier.h> |
| 110 | #include <linux/printk.h> |
| 111 | #include <linux/swapops.h> |
| 112 | |
| 113 | #include <asm/tlbflush.h> |
| 114 | #include <asm/tlb.h> |
| 115 | #include <linux/uaccess.h> |
| 116 | |
| 117 | #include "internal.h" |
| 118 | |
| 119 | /* Internal flags */ |
| 120 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ |
| 121 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ |
| 122 | #define MPOL_MF_WRLOCK (MPOL_MF_INTERNAL << 2) /* Write-lock walked vmas */ |
| 123 | |
| 124 | static struct kmem_cache *policy_cache; |
| 125 | static struct kmem_cache *sn_cache; |
| 126 | |
| 127 | /* Highest zone. An specific allocation for a zone below that is not |
| 128 | policied. */ |
| 129 | enum zone_type policy_zone = 0; |
| 130 | |
| 131 | /* |
| 132 | * run-time system-wide default policy => local allocation |
| 133 | */ |
| 134 | static struct mempolicy default_policy = { |
| 135 | .refcnt = ATOMIC_INIT(1), /* never free it */ |
| 136 | .mode = MPOL_LOCAL, |
| 137 | }; |
| 138 | |
| 139 | static struct mempolicy preferred_node_policy[MAX_NUMNODES]; |
| 140 | |
| 141 | /* |
| 142 | * iw_table is the sysfs-set interleave weight table, a value of 0 denotes |
| 143 | * system-default value should be used. A NULL iw_table also denotes that |
| 144 | * system-default values should be used. Until the system-default table |
| 145 | * is implemented, the system-default is always 1. |
| 146 | * |
| 147 | * iw_table is RCU protected |
| 148 | */ |
| 149 | static u8 __rcu *iw_table; |
| 150 | static DEFINE_MUTEX(iw_table_lock); |
| 151 | |
| 152 | static u8 get_il_weight(int node) |
| 153 | { |
| 154 | u8 *table; |
| 155 | u8 weight; |
| 156 | |
| 157 | rcu_read_lock(); |
| 158 | table = rcu_dereference(iw_table); |
| 159 | /* if no iw_table, use system default */ |
| 160 | weight = table ? table[node] : 1; |
| 161 | /* if value in iw_table is 0, use system default */ |
| 162 | weight = weight ? weight : 1; |
| 163 | rcu_read_unlock(); |
| 164 | return weight; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * numa_nearest_node - Find nearest node by state |
| 169 | * @node: Node id to start the search |
| 170 | * @state: State to filter the search |
| 171 | * |
| 172 | * Lookup the closest node by distance if @nid is not in state. |
| 173 | * |
| 174 | * Return: this @node if it is in state, otherwise the closest node by distance |
| 175 | */ |
| 176 | int numa_nearest_node(int node, unsigned int state) |
| 177 | { |
| 178 | int min_dist = INT_MAX, dist, n, min_node; |
| 179 | |
| 180 | if (state >= NR_NODE_STATES) |
| 181 | return -EINVAL; |
| 182 | |
| 183 | if (node == NUMA_NO_NODE || node_state(node, state)) |
| 184 | return node; |
| 185 | |
| 186 | min_node = node; |
| 187 | for_each_node_state(n, state) { |
| 188 | dist = node_distance(node, n); |
| 189 | if (dist < min_dist) { |
| 190 | min_dist = dist; |
| 191 | min_node = n; |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | return min_node; |
| 196 | } |
| 197 | EXPORT_SYMBOL_GPL(numa_nearest_node); |
| 198 | |
| 199 | struct mempolicy *get_task_policy(struct task_struct *p) |
| 200 | { |
| 201 | struct mempolicy *pol = p->mempolicy; |
| 202 | int node; |
| 203 | |
| 204 | if (pol) |
| 205 | return pol; |
| 206 | |
| 207 | node = numa_node_id(); |
| 208 | if (node != NUMA_NO_NODE) { |
| 209 | pol = &preferred_node_policy[node]; |
| 210 | /* preferred_node_policy is not initialised early in boot */ |
| 211 | if (pol->mode) |
| 212 | return pol; |
| 213 | } |
| 214 | |
| 215 | return &default_policy; |
| 216 | } |
| 217 | |
| 218 | static const struct mempolicy_operations { |
| 219 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); |
| 220 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); |
| 221 | } mpol_ops[MPOL_MAX]; |
| 222 | |
| 223 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) |
| 224 | { |
| 225 | return pol->flags & MPOL_MODE_FLAGS; |
| 226 | } |
| 227 | |
| 228 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, |
| 229 | const nodemask_t *rel) |
| 230 | { |
| 231 | nodemask_t tmp; |
| 232 | nodes_fold(tmp, *orig, nodes_weight(*rel)); |
| 233 | nodes_onto(*ret, tmp, *rel); |
| 234 | } |
| 235 | |
| 236 | static int mpol_new_nodemask(struct mempolicy *pol, const nodemask_t *nodes) |
| 237 | { |
| 238 | if (nodes_empty(*nodes)) |
| 239 | return -EINVAL; |
| 240 | pol->nodes = *nodes; |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) |
| 245 | { |
| 246 | if (nodes_empty(*nodes)) |
| 247 | return -EINVAL; |
| 248 | |
| 249 | nodes_clear(pol->nodes); |
| 250 | node_set(first_node(*nodes), pol->nodes); |
| 251 | return 0; |
| 252 | } |
| 253 | |
| 254 | /* |
| 255 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if |
| 256 | * any, for the new policy. mpol_new() has already validated the nodes |
| 257 | * parameter with respect to the policy mode and flags. |
| 258 | * |
| 259 | * Must be called holding task's alloc_lock to protect task's mems_allowed |
| 260 | * and mempolicy. May also be called holding the mmap_lock for write. |
| 261 | */ |
| 262 | static int mpol_set_nodemask(struct mempolicy *pol, |
| 263 | const nodemask_t *nodes, struct nodemask_scratch *nsc) |
| 264 | { |
| 265 | int ret; |
| 266 | |
| 267 | /* |
| 268 | * Default (pol==NULL) resp. local memory policies are not a |
| 269 | * subject of any remapping. They also do not need any special |
| 270 | * constructor. |
| 271 | */ |
| 272 | if (!pol || pol->mode == MPOL_LOCAL) |
| 273 | return 0; |
| 274 | |
| 275 | /* Check N_MEMORY */ |
| 276 | nodes_and(nsc->mask1, |
| 277 | cpuset_current_mems_allowed, node_states[N_MEMORY]); |
| 278 | |
| 279 | VM_BUG_ON(!nodes); |
| 280 | |
| 281 | if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 282 | mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1); |
| 283 | else |
| 284 | nodes_and(nsc->mask2, *nodes, nsc->mask1); |
| 285 | |
| 286 | if (mpol_store_user_nodemask(pol)) |
| 287 | pol->w.user_nodemask = *nodes; |
| 288 | else |
| 289 | pol->w.cpuset_mems_allowed = cpuset_current_mems_allowed; |
| 290 | |
| 291 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); |
| 292 | return ret; |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * This function just creates a new policy, does some check and simple |
| 297 | * initialization. You must invoke mpol_set_nodemask() to set nodes. |
| 298 | */ |
| 299 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, |
| 300 | nodemask_t *nodes) |
| 301 | { |
| 302 | struct mempolicy *policy; |
| 303 | |
| 304 | if (mode == MPOL_DEFAULT) { |
| 305 | if (nodes && !nodes_empty(*nodes)) |
| 306 | return ERR_PTR(-EINVAL); |
| 307 | return NULL; |
| 308 | } |
| 309 | VM_BUG_ON(!nodes); |
| 310 | |
| 311 | /* |
| 312 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or |
| 313 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). |
| 314 | * All other modes require a valid pointer to a non-empty nodemask. |
| 315 | */ |
| 316 | if (mode == MPOL_PREFERRED) { |
| 317 | if (nodes_empty(*nodes)) { |
| 318 | if (((flags & MPOL_F_STATIC_NODES) || |
| 319 | (flags & MPOL_F_RELATIVE_NODES))) |
| 320 | return ERR_PTR(-EINVAL); |
| 321 | |
| 322 | mode = MPOL_LOCAL; |
| 323 | } |
| 324 | } else if (mode == MPOL_LOCAL) { |
| 325 | if (!nodes_empty(*nodes) || |
| 326 | (flags & MPOL_F_STATIC_NODES) || |
| 327 | (flags & MPOL_F_RELATIVE_NODES)) |
| 328 | return ERR_PTR(-EINVAL); |
| 329 | } else if (nodes_empty(*nodes)) |
| 330 | return ERR_PTR(-EINVAL); |
| 331 | |
| 332 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 333 | if (!policy) |
| 334 | return ERR_PTR(-ENOMEM); |
| 335 | atomic_set(&policy->refcnt, 1); |
| 336 | policy->mode = mode; |
| 337 | policy->flags = flags; |
| 338 | policy->home_node = NUMA_NO_NODE; |
| 339 | |
| 340 | return policy; |
| 341 | } |
| 342 | |
| 343 | /* Slow path of a mpol destructor. */ |
| 344 | void __mpol_put(struct mempolicy *pol) |
| 345 | { |
| 346 | if (!atomic_dec_and_test(&pol->refcnt)) |
| 347 | return; |
| 348 | kmem_cache_free(policy_cache, pol); |
| 349 | } |
| 350 | |
| 351 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) |
| 352 | { |
| 353 | } |
| 354 | |
| 355 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes) |
| 356 | { |
| 357 | nodemask_t tmp; |
| 358 | |
| 359 | if (pol->flags & MPOL_F_STATIC_NODES) |
| 360 | nodes_and(tmp, pol->w.user_nodemask, *nodes); |
| 361 | else if (pol->flags & MPOL_F_RELATIVE_NODES) |
| 362 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
| 363 | else { |
| 364 | nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed, |
| 365 | *nodes); |
| 366 | pol->w.cpuset_mems_allowed = *nodes; |
| 367 | } |
| 368 | |
| 369 | if (nodes_empty(tmp)) |
| 370 | tmp = *nodes; |
| 371 | |
| 372 | pol->nodes = tmp; |
| 373 | } |
| 374 | |
| 375 | static void mpol_rebind_preferred(struct mempolicy *pol, |
| 376 | const nodemask_t *nodes) |
| 377 | { |
| 378 | pol->w.cpuset_mems_allowed = *nodes; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * mpol_rebind_policy - Migrate a policy to a different set of nodes |
| 383 | * |
| 384 | * Per-vma policies are protected by mmap_lock. Allocations using per-task |
| 385 | * policies are protected by task->mems_allowed_seq to prevent a premature |
| 386 | * OOM/allocation failure due to parallel nodemask modification. |
| 387 | */ |
| 388 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask) |
| 389 | { |
| 390 | if (!pol || pol->mode == MPOL_LOCAL) |
| 391 | return; |
| 392 | if (!mpol_store_user_nodemask(pol) && |
| 393 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) |
| 394 | return; |
| 395 | |
| 396 | mpol_ops[pol->mode].rebind(pol, newmask); |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * Wrapper for mpol_rebind_policy() that just requires task |
| 401 | * pointer, and updates task mempolicy. |
| 402 | * |
| 403 | * Called with task's alloc_lock held. |
| 404 | */ |
| 405 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) |
| 406 | { |
| 407 | mpol_rebind_policy(tsk->mempolicy, new); |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Rebind each vma in mm to new nodemask. |
| 412 | * |
| 413 | * Call holding a reference to mm. Takes mm->mmap_lock during call. |
| 414 | */ |
| 415 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) |
| 416 | { |
| 417 | struct vm_area_struct *vma; |
| 418 | VMA_ITERATOR(vmi, mm, 0); |
| 419 | |
| 420 | mmap_write_lock(mm); |
| 421 | for_each_vma(vmi, vma) { |
| 422 | vma_start_write(vma); |
| 423 | mpol_rebind_policy(vma->vm_policy, new); |
| 424 | } |
| 425 | mmap_write_unlock(mm); |
| 426 | } |
| 427 | |
| 428 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { |
| 429 | [MPOL_DEFAULT] = { |
| 430 | .rebind = mpol_rebind_default, |
| 431 | }, |
| 432 | [MPOL_INTERLEAVE] = { |
| 433 | .create = mpol_new_nodemask, |
| 434 | .rebind = mpol_rebind_nodemask, |
| 435 | }, |
| 436 | [MPOL_PREFERRED] = { |
| 437 | .create = mpol_new_preferred, |
| 438 | .rebind = mpol_rebind_preferred, |
| 439 | }, |
| 440 | [MPOL_BIND] = { |
| 441 | .create = mpol_new_nodemask, |
| 442 | .rebind = mpol_rebind_nodemask, |
| 443 | }, |
| 444 | [MPOL_LOCAL] = { |
| 445 | .rebind = mpol_rebind_default, |
| 446 | }, |
| 447 | [MPOL_PREFERRED_MANY] = { |
| 448 | .create = mpol_new_nodemask, |
| 449 | .rebind = mpol_rebind_preferred, |
| 450 | }, |
| 451 | [MPOL_WEIGHTED_INTERLEAVE] = { |
| 452 | .create = mpol_new_nodemask, |
| 453 | .rebind = mpol_rebind_nodemask, |
| 454 | }, |
| 455 | }; |
| 456 | |
| 457 | static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist, |
| 458 | unsigned long flags); |
| 459 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *pol, |
| 460 | pgoff_t ilx, int *nid); |
| 461 | |
| 462 | static bool strictly_unmovable(unsigned long flags) |
| 463 | { |
| 464 | /* |
| 465 | * STRICT without MOVE flags lets do_mbind() fail immediately with -EIO |
| 466 | * if any misplaced page is found. |
| 467 | */ |
| 468 | return (flags & (MPOL_MF_STRICT | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) == |
| 469 | MPOL_MF_STRICT; |
| 470 | } |
| 471 | |
| 472 | struct migration_mpol { /* for alloc_migration_target_by_mpol() */ |
| 473 | struct mempolicy *pol; |
| 474 | pgoff_t ilx; |
| 475 | }; |
| 476 | |
| 477 | struct queue_pages { |
| 478 | struct list_head *pagelist; |
| 479 | unsigned long flags; |
| 480 | nodemask_t *nmask; |
| 481 | unsigned long start; |
| 482 | unsigned long end; |
| 483 | struct vm_area_struct *first; |
| 484 | struct folio *large; /* note last large folio encountered */ |
| 485 | long nr_failed; /* could not be isolated at this time */ |
| 486 | }; |
| 487 | |
| 488 | /* |
| 489 | * Check if the folio's nid is in qp->nmask. |
| 490 | * |
| 491 | * If MPOL_MF_INVERT is set in qp->flags, check if the nid is |
| 492 | * in the invert of qp->nmask. |
| 493 | */ |
| 494 | static inline bool queue_folio_required(struct folio *folio, |
| 495 | struct queue_pages *qp) |
| 496 | { |
| 497 | int nid = folio_nid(folio); |
| 498 | unsigned long flags = qp->flags; |
| 499 | |
| 500 | return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT); |
| 501 | } |
| 502 | |
| 503 | static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) |
| 504 | { |
| 505 | struct folio *folio; |
| 506 | struct queue_pages *qp = walk->private; |
| 507 | |
| 508 | if (unlikely(is_pmd_migration_entry(*pmd))) { |
| 509 | qp->nr_failed++; |
| 510 | return; |
| 511 | } |
| 512 | folio = pmd_folio(*pmd); |
| 513 | if (is_huge_zero_folio(folio)) { |
| 514 | walk->action = ACTION_CONTINUE; |
| 515 | return; |
| 516 | } |
| 517 | if (!queue_folio_required(folio, qp)) |
| 518 | return; |
| 519 | if (!(qp->flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) || |
| 520 | !vma_migratable(walk->vma) || |
| 521 | !migrate_folio_add(folio, qp->pagelist, qp->flags)) |
| 522 | qp->nr_failed++; |
| 523 | } |
| 524 | |
| 525 | /* |
| 526 | * Scan through folios, checking if they satisfy the required conditions, |
| 527 | * moving them from LRU to local pagelist for migration if they do (or not). |
| 528 | * |
| 529 | * queue_folios_pte_range() has two possible return values: |
| 530 | * 0 - continue walking to scan for more, even if an existing folio on the |
| 531 | * wrong node could not be isolated and queued for migration. |
| 532 | * -EIO - only MPOL_MF_STRICT was specified, without MPOL_MF_MOVE or ..._ALL, |
| 533 | * and an existing folio was on a node that does not follow the policy. |
| 534 | */ |
| 535 | static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, |
| 536 | unsigned long end, struct mm_walk *walk) |
| 537 | { |
| 538 | struct vm_area_struct *vma = walk->vma; |
| 539 | struct folio *folio; |
| 540 | struct queue_pages *qp = walk->private; |
| 541 | unsigned long flags = qp->flags; |
| 542 | pte_t *pte, *mapped_pte; |
| 543 | pte_t ptent; |
| 544 | spinlock_t *ptl; |
| 545 | |
| 546 | ptl = pmd_trans_huge_lock(pmd, vma); |
| 547 | if (ptl) { |
| 548 | queue_folios_pmd(pmd, walk); |
| 549 | spin_unlock(ptl); |
| 550 | goto out; |
| 551 | } |
| 552 | |
| 553 | mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); |
| 554 | if (!pte) { |
| 555 | walk->action = ACTION_AGAIN; |
| 556 | return 0; |
| 557 | } |
| 558 | for (; addr != end; pte++, addr += PAGE_SIZE) { |
| 559 | ptent = ptep_get(pte); |
| 560 | if (pte_none(ptent)) |
| 561 | continue; |
| 562 | if (!pte_present(ptent)) { |
| 563 | if (is_migration_entry(pte_to_swp_entry(ptent))) |
| 564 | qp->nr_failed++; |
| 565 | continue; |
| 566 | } |
| 567 | folio = vm_normal_folio(vma, addr, ptent); |
| 568 | if (!folio || folio_is_zone_device(folio)) |
| 569 | continue; |
| 570 | /* |
| 571 | * vm_normal_folio() filters out zero pages, but there might |
| 572 | * still be reserved folios to skip, perhaps in a VDSO. |
| 573 | */ |
| 574 | if (folio_test_reserved(folio)) |
| 575 | continue; |
| 576 | if (!queue_folio_required(folio, qp)) |
| 577 | continue; |
| 578 | if (folio_test_large(folio)) { |
| 579 | /* |
| 580 | * A large folio can only be isolated from LRU once, |
| 581 | * but may be mapped by many PTEs (and Copy-On-Write may |
| 582 | * intersperse PTEs of other, order 0, folios). This is |
| 583 | * a common case, so don't mistake it for failure (but |
| 584 | * there can be other cases of multi-mapped pages which |
| 585 | * this quick check does not help to filter out - and a |
| 586 | * search of the pagelist might grow to be prohibitive). |
| 587 | * |
| 588 | * migrate_pages(&pagelist) returns nr_failed folios, so |
| 589 | * check "large" now so that queue_pages_range() returns |
| 590 | * a comparable nr_failed folios. This does imply that |
| 591 | * if folio could not be isolated for some racy reason |
| 592 | * at its first PTE, later PTEs will not give it another |
| 593 | * chance of isolation; but keeps the accounting simple. |
| 594 | */ |
| 595 | if (folio == qp->large) |
| 596 | continue; |
| 597 | qp->large = folio; |
| 598 | } |
| 599 | if (!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) || |
| 600 | !vma_migratable(vma) || |
| 601 | !migrate_folio_add(folio, qp->pagelist, flags)) { |
| 602 | qp->nr_failed++; |
| 603 | if (strictly_unmovable(flags)) |
| 604 | break; |
| 605 | } |
| 606 | } |
| 607 | pte_unmap_unlock(mapped_pte, ptl); |
| 608 | cond_resched(); |
| 609 | out: |
| 610 | if (qp->nr_failed && strictly_unmovable(flags)) |
| 611 | return -EIO; |
| 612 | return 0; |
| 613 | } |
| 614 | |
| 615 | static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask, |
| 616 | unsigned long addr, unsigned long end, |
| 617 | struct mm_walk *walk) |
| 618 | { |
| 619 | #ifdef CONFIG_HUGETLB_PAGE |
| 620 | struct queue_pages *qp = walk->private; |
| 621 | unsigned long flags = qp->flags; |
| 622 | struct folio *folio; |
| 623 | spinlock_t *ptl; |
| 624 | pte_t entry; |
| 625 | |
| 626 | ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); |
| 627 | entry = huge_ptep_get(pte); |
| 628 | if (!pte_present(entry)) { |
| 629 | if (unlikely(is_hugetlb_entry_migration(entry))) |
| 630 | qp->nr_failed++; |
| 631 | goto unlock; |
| 632 | } |
| 633 | folio = pfn_folio(pte_pfn(entry)); |
| 634 | if (!queue_folio_required(folio, qp)) |
| 635 | goto unlock; |
| 636 | if (!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) || |
| 637 | !vma_migratable(walk->vma)) { |
| 638 | qp->nr_failed++; |
| 639 | goto unlock; |
| 640 | } |
| 641 | /* |
| 642 | * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio. |
| 643 | * Choosing not to migrate a shared folio is not counted as a failure. |
| 644 | * |
| 645 | * See folio_likely_mapped_shared() on possible imprecision when we |
| 646 | * cannot easily detect if a folio is shared. |
| 647 | */ |
| 648 | if ((flags & MPOL_MF_MOVE_ALL) || |
| 649 | (!folio_likely_mapped_shared(folio) && !hugetlb_pmd_shared(pte))) |
| 650 | if (!isolate_hugetlb(folio, qp->pagelist)) |
| 651 | qp->nr_failed++; |
| 652 | unlock: |
| 653 | spin_unlock(ptl); |
| 654 | if (qp->nr_failed && strictly_unmovable(flags)) |
| 655 | return -EIO; |
| 656 | #endif |
| 657 | return 0; |
| 658 | } |
| 659 | |
| 660 | #ifdef CONFIG_NUMA_BALANCING |
| 661 | /* |
| 662 | * This is used to mark a range of virtual addresses to be inaccessible. |
| 663 | * These are later cleared by a NUMA hinting fault. Depending on these |
| 664 | * faults, pages may be migrated for better NUMA placement. |
| 665 | * |
| 666 | * This is assuming that NUMA faults are handled using PROT_NONE. If |
| 667 | * an architecture makes a different choice, it will need further |
| 668 | * changes to the core. |
| 669 | */ |
| 670 | unsigned long change_prot_numa(struct vm_area_struct *vma, |
| 671 | unsigned long addr, unsigned long end) |
| 672 | { |
| 673 | struct mmu_gather tlb; |
| 674 | long nr_updated; |
| 675 | |
| 676 | tlb_gather_mmu(&tlb, vma->vm_mm); |
| 677 | |
| 678 | nr_updated = change_protection(&tlb, vma, addr, end, MM_CP_PROT_NUMA); |
| 679 | if (nr_updated > 0) |
| 680 | count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); |
| 681 | |
| 682 | tlb_finish_mmu(&tlb); |
| 683 | |
| 684 | return nr_updated; |
| 685 | } |
| 686 | #endif /* CONFIG_NUMA_BALANCING */ |
| 687 | |
| 688 | static int queue_pages_test_walk(unsigned long start, unsigned long end, |
| 689 | struct mm_walk *walk) |
| 690 | { |
| 691 | struct vm_area_struct *next, *vma = walk->vma; |
| 692 | struct queue_pages *qp = walk->private; |
| 693 | unsigned long flags = qp->flags; |
| 694 | |
| 695 | /* range check first */ |
| 696 | VM_BUG_ON_VMA(!range_in_vma(vma, start, end), vma); |
| 697 | |
| 698 | if (!qp->first) { |
| 699 | qp->first = vma; |
| 700 | if (!(flags & MPOL_MF_DISCONTIG_OK) && |
| 701 | (qp->start < vma->vm_start)) |
| 702 | /* hole at head side of range */ |
| 703 | return -EFAULT; |
| 704 | } |
| 705 | next = find_vma(vma->vm_mm, vma->vm_end); |
| 706 | if (!(flags & MPOL_MF_DISCONTIG_OK) && |
| 707 | ((vma->vm_end < qp->end) && |
| 708 | (!next || vma->vm_end < next->vm_start))) |
| 709 | /* hole at middle or tail of range */ |
| 710 | return -EFAULT; |
| 711 | |
| 712 | /* |
| 713 | * Need check MPOL_MF_STRICT to return -EIO if possible |
| 714 | * regardless of vma_migratable |
| 715 | */ |
| 716 | if (!vma_migratable(vma) && |
| 717 | !(flags & MPOL_MF_STRICT)) |
| 718 | return 1; |
| 719 | |
| 720 | /* |
| 721 | * Check page nodes, and queue pages to move, in the current vma. |
| 722 | * But if no moving, and no strict checking, the scan can be skipped. |
| 723 | */ |
| 724 | if (flags & (MPOL_MF_STRICT | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 725 | return 0; |
| 726 | return 1; |
| 727 | } |
| 728 | |
| 729 | static const struct mm_walk_ops queue_pages_walk_ops = { |
| 730 | .hugetlb_entry = queue_folios_hugetlb, |
| 731 | .pmd_entry = queue_folios_pte_range, |
| 732 | .test_walk = queue_pages_test_walk, |
| 733 | .walk_lock = PGWALK_RDLOCK, |
| 734 | }; |
| 735 | |
| 736 | static const struct mm_walk_ops queue_pages_lock_vma_walk_ops = { |
| 737 | .hugetlb_entry = queue_folios_hugetlb, |
| 738 | .pmd_entry = queue_folios_pte_range, |
| 739 | .test_walk = queue_pages_test_walk, |
| 740 | .walk_lock = PGWALK_WRLOCK, |
| 741 | }; |
| 742 | |
| 743 | /* |
| 744 | * Walk through page tables and collect pages to be migrated. |
| 745 | * |
| 746 | * If pages found in a given range are not on the required set of @nodes, |
| 747 | * and migration is allowed, they are isolated and queued to @pagelist. |
| 748 | * |
| 749 | * queue_pages_range() may return: |
| 750 | * 0 - all pages already on the right node, or successfully queued for moving |
| 751 | * (or neither strict checking nor moving requested: only range checking). |
| 752 | * >0 - this number of misplaced folios could not be queued for moving |
| 753 | * (a hugetlbfs page or a transparent huge page being counted as 1). |
| 754 | * -EIO - a misplaced page found, when MPOL_MF_STRICT specified without MOVEs. |
| 755 | * -EFAULT - a hole in the memory range, when MPOL_MF_DISCONTIG_OK unspecified. |
| 756 | */ |
| 757 | static long |
| 758 | queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end, |
| 759 | nodemask_t *nodes, unsigned long flags, |
| 760 | struct list_head *pagelist) |
| 761 | { |
| 762 | int err; |
| 763 | struct queue_pages qp = { |
| 764 | .pagelist = pagelist, |
| 765 | .flags = flags, |
| 766 | .nmask = nodes, |
| 767 | .start = start, |
| 768 | .end = end, |
| 769 | .first = NULL, |
| 770 | }; |
| 771 | const struct mm_walk_ops *ops = (flags & MPOL_MF_WRLOCK) ? |
| 772 | &queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops; |
| 773 | |
| 774 | err = walk_page_range(mm, start, end, ops, &qp); |
| 775 | |
| 776 | if (!qp.first) |
| 777 | /* whole range in hole */ |
| 778 | err = -EFAULT; |
| 779 | |
| 780 | return err ? : qp.nr_failed; |
| 781 | } |
| 782 | |
| 783 | /* |
| 784 | * Apply policy to a single VMA |
| 785 | * This must be called with the mmap_lock held for writing. |
| 786 | */ |
| 787 | static int vma_replace_policy(struct vm_area_struct *vma, |
| 788 | struct mempolicy *pol) |
| 789 | { |
| 790 | int err; |
| 791 | struct mempolicy *old; |
| 792 | struct mempolicy *new; |
| 793 | |
| 794 | vma_assert_write_locked(vma); |
| 795 | |
| 796 | new = mpol_dup(pol); |
| 797 | if (IS_ERR(new)) |
| 798 | return PTR_ERR(new); |
| 799 | |
| 800 | if (vma->vm_ops && vma->vm_ops->set_policy) { |
| 801 | err = vma->vm_ops->set_policy(vma, new); |
| 802 | if (err) |
| 803 | goto err_out; |
| 804 | } |
| 805 | |
| 806 | old = vma->vm_policy; |
| 807 | vma->vm_policy = new; /* protected by mmap_lock */ |
| 808 | mpol_put(old); |
| 809 | |
| 810 | return 0; |
| 811 | err_out: |
| 812 | mpol_put(new); |
| 813 | return err; |
| 814 | } |
| 815 | |
| 816 | /* Split or merge the VMA (if required) and apply the new policy */ |
| 817 | static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma, |
| 818 | struct vm_area_struct **prev, unsigned long start, |
| 819 | unsigned long end, struct mempolicy *new_pol) |
| 820 | { |
| 821 | unsigned long vmstart, vmend; |
| 822 | |
| 823 | vmend = min(end, vma->vm_end); |
| 824 | if (start > vma->vm_start) { |
| 825 | *prev = vma; |
| 826 | vmstart = start; |
| 827 | } else { |
| 828 | vmstart = vma->vm_start; |
| 829 | } |
| 830 | |
| 831 | if (mpol_equal(vma->vm_policy, new_pol)) { |
| 832 | *prev = vma; |
| 833 | return 0; |
| 834 | } |
| 835 | |
| 836 | vma = vma_modify_policy(vmi, *prev, vma, vmstart, vmend, new_pol); |
| 837 | if (IS_ERR(vma)) |
| 838 | return PTR_ERR(vma); |
| 839 | |
| 840 | *prev = vma; |
| 841 | return vma_replace_policy(vma, new_pol); |
| 842 | } |
| 843 | |
| 844 | /* Set the process memory policy */ |
| 845 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, |
| 846 | nodemask_t *nodes) |
| 847 | { |
| 848 | struct mempolicy *new, *old; |
| 849 | NODEMASK_SCRATCH(scratch); |
| 850 | int ret; |
| 851 | |
| 852 | if (!scratch) |
| 853 | return -ENOMEM; |
| 854 | |
| 855 | new = mpol_new(mode, flags, nodes); |
| 856 | if (IS_ERR(new)) { |
| 857 | ret = PTR_ERR(new); |
| 858 | goto out; |
| 859 | } |
| 860 | |
| 861 | task_lock(current); |
| 862 | ret = mpol_set_nodemask(new, nodes, scratch); |
| 863 | if (ret) { |
| 864 | task_unlock(current); |
| 865 | mpol_put(new); |
| 866 | goto out; |
| 867 | } |
| 868 | |
| 869 | old = current->mempolicy; |
| 870 | current->mempolicy = new; |
| 871 | if (new && (new->mode == MPOL_INTERLEAVE || |
| 872 | new->mode == MPOL_WEIGHTED_INTERLEAVE)) { |
| 873 | current->il_prev = MAX_NUMNODES-1; |
| 874 | current->il_weight = 0; |
| 875 | } |
| 876 | task_unlock(current); |
| 877 | mpol_put(old); |
| 878 | ret = 0; |
| 879 | out: |
| 880 | NODEMASK_SCRATCH_FREE(scratch); |
| 881 | return ret; |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Return nodemask for policy for get_mempolicy() query |
| 886 | * |
| 887 | * Called with task's alloc_lock held |
| 888 | */ |
| 889 | static void get_policy_nodemask(struct mempolicy *pol, nodemask_t *nodes) |
| 890 | { |
| 891 | nodes_clear(*nodes); |
| 892 | if (pol == &default_policy) |
| 893 | return; |
| 894 | |
| 895 | switch (pol->mode) { |
| 896 | case MPOL_BIND: |
| 897 | case MPOL_INTERLEAVE: |
| 898 | case MPOL_PREFERRED: |
| 899 | case MPOL_PREFERRED_MANY: |
| 900 | case MPOL_WEIGHTED_INTERLEAVE: |
| 901 | *nodes = pol->nodes; |
| 902 | break; |
| 903 | case MPOL_LOCAL: |
| 904 | /* return empty node mask for local allocation */ |
| 905 | break; |
| 906 | default: |
| 907 | BUG(); |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | static int lookup_node(struct mm_struct *mm, unsigned long addr) |
| 912 | { |
| 913 | struct page *p = NULL; |
| 914 | int ret; |
| 915 | |
| 916 | ret = get_user_pages_fast(addr & PAGE_MASK, 1, 0, &p); |
| 917 | if (ret > 0) { |
| 918 | ret = page_to_nid(p); |
| 919 | put_page(p); |
| 920 | } |
| 921 | return ret; |
| 922 | } |
| 923 | |
| 924 | /* Retrieve NUMA policy */ |
| 925 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, |
| 926 | unsigned long addr, unsigned long flags) |
| 927 | { |
| 928 | int err; |
| 929 | struct mm_struct *mm = current->mm; |
| 930 | struct vm_area_struct *vma = NULL; |
| 931 | struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL; |
| 932 | |
| 933 | if (flags & |
| 934 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) |
| 935 | return -EINVAL; |
| 936 | |
| 937 | if (flags & MPOL_F_MEMS_ALLOWED) { |
| 938 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) |
| 939 | return -EINVAL; |
| 940 | *policy = 0; /* just so it's initialized */ |
| 941 | task_lock(current); |
| 942 | *nmask = cpuset_current_mems_allowed; |
| 943 | task_unlock(current); |
| 944 | return 0; |
| 945 | } |
| 946 | |
| 947 | if (flags & MPOL_F_ADDR) { |
| 948 | pgoff_t ilx; /* ignored here */ |
| 949 | /* |
| 950 | * Do NOT fall back to task policy if the |
| 951 | * vma/shared policy at addr is NULL. We |
| 952 | * want to return MPOL_DEFAULT in this case. |
| 953 | */ |
| 954 | mmap_read_lock(mm); |
| 955 | vma = vma_lookup(mm, addr); |
| 956 | if (!vma) { |
| 957 | mmap_read_unlock(mm); |
| 958 | return -EFAULT; |
| 959 | } |
| 960 | pol = __get_vma_policy(vma, addr, &ilx); |
| 961 | } else if (addr) |
| 962 | return -EINVAL; |
| 963 | |
| 964 | if (!pol) |
| 965 | pol = &default_policy; /* indicates default behavior */ |
| 966 | |
| 967 | if (flags & MPOL_F_NODE) { |
| 968 | if (flags & MPOL_F_ADDR) { |
| 969 | /* |
| 970 | * Take a refcount on the mpol, because we are about to |
| 971 | * drop the mmap_lock, after which only "pol" remains |
| 972 | * valid, "vma" is stale. |
| 973 | */ |
| 974 | pol_refcount = pol; |
| 975 | vma = NULL; |
| 976 | mpol_get(pol); |
| 977 | mmap_read_unlock(mm); |
| 978 | err = lookup_node(mm, addr); |
| 979 | if (err < 0) |
| 980 | goto out; |
| 981 | *policy = err; |
| 982 | } else if (pol == current->mempolicy && |
| 983 | pol->mode == MPOL_INTERLEAVE) { |
| 984 | *policy = next_node_in(current->il_prev, pol->nodes); |
| 985 | } else if (pol == current->mempolicy && |
| 986 | pol->mode == MPOL_WEIGHTED_INTERLEAVE) { |
| 987 | if (current->il_weight) |
| 988 | *policy = current->il_prev; |
| 989 | else |
| 990 | *policy = next_node_in(current->il_prev, |
| 991 | pol->nodes); |
| 992 | } else { |
| 993 | err = -EINVAL; |
| 994 | goto out; |
| 995 | } |
| 996 | } else { |
| 997 | *policy = pol == &default_policy ? MPOL_DEFAULT : |
| 998 | pol->mode; |
| 999 | /* |
| 1000 | * Internal mempolicy flags must be masked off before exposing |
| 1001 | * the policy to userspace. |
| 1002 | */ |
| 1003 | *policy |= (pol->flags & MPOL_MODE_FLAGS); |
| 1004 | } |
| 1005 | |
| 1006 | err = 0; |
| 1007 | if (nmask) { |
| 1008 | if (mpol_store_user_nodemask(pol)) { |
| 1009 | *nmask = pol->w.user_nodemask; |
| 1010 | } else { |
| 1011 | task_lock(current); |
| 1012 | get_policy_nodemask(pol, nmask); |
| 1013 | task_unlock(current); |
| 1014 | } |
| 1015 | } |
| 1016 | |
| 1017 | out: |
| 1018 | mpol_cond_put(pol); |
| 1019 | if (vma) |
| 1020 | mmap_read_unlock(mm); |
| 1021 | if (pol_refcount) |
| 1022 | mpol_put(pol_refcount); |
| 1023 | return err; |
| 1024 | } |
| 1025 | |
| 1026 | #ifdef CONFIG_MIGRATION |
| 1027 | static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist, |
| 1028 | unsigned long flags) |
| 1029 | { |
| 1030 | /* |
| 1031 | * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio. |
| 1032 | * Choosing not to migrate a shared folio is not counted as a failure. |
| 1033 | * |
| 1034 | * See folio_likely_mapped_shared() on possible imprecision when we |
| 1035 | * cannot easily detect if a folio is shared. |
| 1036 | */ |
| 1037 | if ((flags & MPOL_MF_MOVE_ALL) || !folio_likely_mapped_shared(folio)) { |
| 1038 | if (folio_isolate_lru(folio)) { |
| 1039 | list_add_tail(&folio->lru, foliolist); |
| 1040 | node_stat_mod_folio(folio, |
| 1041 | NR_ISOLATED_ANON + folio_is_file_lru(folio), |
| 1042 | folio_nr_pages(folio)); |
| 1043 | } else { |
| 1044 | /* |
| 1045 | * Non-movable folio may reach here. And, there may be |
| 1046 | * temporary off LRU folios or non-LRU movable folios. |
| 1047 | * Treat them as unmovable folios since they can't be |
| 1048 | * isolated, so they can't be moved at the moment. |
| 1049 | */ |
| 1050 | return false; |
| 1051 | } |
| 1052 | } |
| 1053 | return true; |
| 1054 | } |
| 1055 | |
| 1056 | /* |
| 1057 | * Migrate pages from one node to a target node. |
| 1058 | * Returns error or the number of pages not migrated. |
| 1059 | */ |
| 1060 | static long migrate_to_node(struct mm_struct *mm, int source, int dest, |
| 1061 | int flags) |
| 1062 | { |
| 1063 | nodemask_t nmask; |
| 1064 | struct vm_area_struct *vma; |
| 1065 | LIST_HEAD(pagelist); |
| 1066 | long nr_failed; |
| 1067 | long err = 0; |
| 1068 | struct migration_target_control mtc = { |
| 1069 | .nid = dest, |
| 1070 | .gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, |
| 1071 | .reason = MR_SYSCALL, |
| 1072 | }; |
| 1073 | |
| 1074 | nodes_clear(nmask); |
| 1075 | node_set(source, nmask); |
| 1076 | |
| 1077 | VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); |
| 1078 | |
| 1079 | mmap_read_lock(mm); |
| 1080 | vma = find_vma(mm, 0); |
| 1081 | |
| 1082 | /* |
| 1083 | * This does not migrate the range, but isolates all pages that |
| 1084 | * need migration. Between passing in the full user address |
| 1085 | * space range and MPOL_MF_DISCONTIG_OK, this call cannot fail, |
| 1086 | * but passes back the count of pages which could not be isolated. |
| 1087 | */ |
| 1088 | nr_failed = queue_pages_range(mm, vma->vm_start, mm->task_size, &nmask, |
| 1089 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); |
| 1090 | mmap_read_unlock(mm); |
| 1091 | |
| 1092 | if (!list_empty(&pagelist)) { |
| 1093 | err = migrate_pages(&pagelist, alloc_migration_target, NULL, |
| 1094 | (unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL); |
| 1095 | if (err) |
| 1096 | putback_movable_pages(&pagelist); |
| 1097 | } |
| 1098 | |
| 1099 | if (err >= 0) |
| 1100 | err += nr_failed; |
| 1101 | return err; |
| 1102 | } |
| 1103 | |
| 1104 | /* |
| 1105 | * Move pages between the two nodesets so as to preserve the physical |
| 1106 | * layout as much as possible. |
| 1107 | * |
| 1108 | * Returns the number of page that could not be moved. |
| 1109 | */ |
| 1110 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 1111 | const nodemask_t *to, int flags) |
| 1112 | { |
| 1113 | long nr_failed = 0; |
| 1114 | long err = 0; |
| 1115 | nodemask_t tmp; |
| 1116 | |
| 1117 | lru_cache_disable(); |
| 1118 | |
| 1119 | /* |
| 1120 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' |
| 1121 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' |
| 1122 | * bit in 'tmp', and return that <source, dest> pair for migration. |
| 1123 | * The pair of nodemasks 'to' and 'from' define the map. |
| 1124 | * |
| 1125 | * If no pair of bits is found that way, fallback to picking some |
| 1126 | * pair of 'source' and 'dest' bits that are not the same. If the |
| 1127 | * 'source' and 'dest' bits are the same, this represents a node |
| 1128 | * that will be migrating to itself, so no pages need move. |
| 1129 | * |
| 1130 | * If no bits are left in 'tmp', or if all remaining bits left |
| 1131 | * in 'tmp' correspond to the same bit in 'to', return false |
| 1132 | * (nothing left to migrate). |
| 1133 | * |
| 1134 | * This lets us pick a pair of nodes to migrate between, such that |
| 1135 | * if possible the dest node is not already occupied by some other |
| 1136 | * source node, minimizing the risk of overloading the memory on a |
| 1137 | * node that would happen if we migrated incoming memory to a node |
| 1138 | * before migrating outgoing memory source that same node. |
| 1139 | * |
| 1140 | * A single scan of tmp is sufficient. As we go, we remember the |
| 1141 | * most recent <s, d> pair that moved (s != d). If we find a pair |
| 1142 | * that not only moved, but what's better, moved to an empty slot |
| 1143 | * (d is not set in tmp), then we break out then, with that pair. |
| 1144 | * Otherwise when we finish scanning from_tmp, we at least have the |
| 1145 | * most recent <s, d> pair that moved. If we get all the way through |
| 1146 | * the scan of tmp without finding any node that moved, much less |
| 1147 | * moved to an empty node, then there is nothing left worth migrating. |
| 1148 | */ |
| 1149 | |
| 1150 | tmp = *from; |
| 1151 | while (!nodes_empty(tmp)) { |
| 1152 | int s, d; |
| 1153 | int source = NUMA_NO_NODE; |
| 1154 | int dest = 0; |
| 1155 | |
| 1156 | for_each_node_mask(s, tmp) { |
| 1157 | |
| 1158 | /* |
| 1159 | * do_migrate_pages() tries to maintain the relative |
| 1160 | * node relationship of the pages established between |
| 1161 | * threads and memory areas. |
| 1162 | * |
| 1163 | * However if the number of source nodes is not equal to |
| 1164 | * the number of destination nodes we can not preserve |
| 1165 | * this node relative relationship. In that case, skip |
| 1166 | * copying memory from a node that is in the destination |
| 1167 | * mask. |
| 1168 | * |
| 1169 | * Example: [2,3,4] -> [3,4,5] moves everything. |
| 1170 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. |
| 1171 | */ |
| 1172 | |
| 1173 | if ((nodes_weight(*from) != nodes_weight(*to)) && |
| 1174 | (node_isset(s, *to))) |
| 1175 | continue; |
| 1176 | |
| 1177 | d = node_remap(s, *from, *to); |
| 1178 | if (s == d) |
| 1179 | continue; |
| 1180 | |
| 1181 | source = s; /* Node moved. Memorize */ |
| 1182 | dest = d; |
| 1183 | |
| 1184 | /* dest not in remaining from nodes? */ |
| 1185 | if (!node_isset(dest, tmp)) |
| 1186 | break; |
| 1187 | } |
| 1188 | if (source == NUMA_NO_NODE) |
| 1189 | break; |
| 1190 | |
| 1191 | node_clear(source, tmp); |
| 1192 | err = migrate_to_node(mm, source, dest, flags); |
| 1193 | if (err > 0) |
| 1194 | nr_failed += err; |
| 1195 | if (err < 0) |
| 1196 | break; |
| 1197 | } |
| 1198 | |
| 1199 | lru_cache_enable(); |
| 1200 | if (err < 0) |
| 1201 | return err; |
| 1202 | return (nr_failed < INT_MAX) ? nr_failed : INT_MAX; |
| 1203 | } |
| 1204 | |
| 1205 | /* |
| 1206 | * Allocate a new folio for page migration, according to NUMA mempolicy. |
| 1207 | */ |
| 1208 | static struct folio *alloc_migration_target_by_mpol(struct folio *src, |
| 1209 | unsigned long private) |
| 1210 | { |
| 1211 | struct migration_mpol *mmpol = (struct migration_mpol *)private; |
| 1212 | struct mempolicy *pol = mmpol->pol; |
| 1213 | pgoff_t ilx = mmpol->ilx; |
| 1214 | struct page *page; |
| 1215 | unsigned int order; |
| 1216 | int nid = numa_node_id(); |
| 1217 | gfp_t gfp; |
| 1218 | |
| 1219 | order = folio_order(src); |
| 1220 | ilx += src->index >> order; |
| 1221 | |
| 1222 | if (folio_test_hugetlb(src)) { |
| 1223 | nodemask_t *nodemask; |
| 1224 | struct hstate *h; |
| 1225 | |
| 1226 | h = folio_hstate(src); |
| 1227 | gfp = htlb_alloc_mask(h); |
| 1228 | nodemask = policy_nodemask(gfp, pol, ilx, &nid); |
| 1229 | return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp, |
| 1230 | htlb_allow_alloc_fallback(MR_MEMPOLICY_MBIND)); |
| 1231 | } |
| 1232 | |
| 1233 | if (folio_test_large(src)) |
| 1234 | gfp = GFP_TRANSHUGE; |
| 1235 | else |
| 1236 | gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; |
| 1237 | |
| 1238 | page = alloc_pages_mpol(gfp, order, pol, ilx, nid); |
| 1239 | return page_rmappable_folio(page); |
| 1240 | } |
| 1241 | #else |
| 1242 | |
| 1243 | static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist, |
| 1244 | unsigned long flags) |
| 1245 | { |
| 1246 | return false; |
| 1247 | } |
| 1248 | |
| 1249 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
| 1250 | const nodemask_t *to, int flags) |
| 1251 | { |
| 1252 | return -ENOSYS; |
| 1253 | } |
| 1254 | |
| 1255 | static struct folio *alloc_migration_target_by_mpol(struct folio *src, |
| 1256 | unsigned long private) |
| 1257 | { |
| 1258 | return NULL; |
| 1259 | } |
| 1260 | #endif |
| 1261 | |
| 1262 | static long do_mbind(unsigned long start, unsigned long len, |
| 1263 | unsigned short mode, unsigned short mode_flags, |
| 1264 | nodemask_t *nmask, unsigned long flags) |
| 1265 | { |
| 1266 | struct mm_struct *mm = current->mm; |
| 1267 | struct vm_area_struct *vma, *prev; |
| 1268 | struct vma_iterator vmi; |
| 1269 | struct migration_mpol mmpol; |
| 1270 | struct mempolicy *new; |
| 1271 | unsigned long end; |
| 1272 | long err; |
| 1273 | long nr_failed; |
| 1274 | LIST_HEAD(pagelist); |
| 1275 | |
| 1276 | if (flags & ~(unsigned long)MPOL_MF_VALID) |
| 1277 | return -EINVAL; |
| 1278 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) |
| 1279 | return -EPERM; |
| 1280 | |
| 1281 | if (start & ~PAGE_MASK) |
| 1282 | return -EINVAL; |
| 1283 | |
| 1284 | if (mode == MPOL_DEFAULT) |
| 1285 | flags &= ~MPOL_MF_STRICT; |
| 1286 | |
| 1287 | len = PAGE_ALIGN(len); |
| 1288 | end = start + len; |
| 1289 | |
| 1290 | if (end < start) |
| 1291 | return -EINVAL; |
| 1292 | if (end == start) |
| 1293 | return 0; |
| 1294 | |
| 1295 | new = mpol_new(mode, mode_flags, nmask); |
| 1296 | if (IS_ERR(new)) |
| 1297 | return PTR_ERR(new); |
| 1298 | |
| 1299 | /* |
| 1300 | * If we are using the default policy then operation |
| 1301 | * on discontinuous address spaces is okay after all |
| 1302 | */ |
| 1303 | if (!new) |
| 1304 | flags |= MPOL_MF_DISCONTIG_OK; |
| 1305 | |
| 1306 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 1307 | lru_cache_disable(); |
| 1308 | { |
| 1309 | NODEMASK_SCRATCH(scratch); |
| 1310 | if (scratch) { |
| 1311 | mmap_write_lock(mm); |
| 1312 | err = mpol_set_nodemask(new, nmask, scratch); |
| 1313 | if (err) |
| 1314 | mmap_write_unlock(mm); |
| 1315 | } else |
| 1316 | err = -ENOMEM; |
| 1317 | NODEMASK_SCRATCH_FREE(scratch); |
| 1318 | } |
| 1319 | if (err) |
| 1320 | goto mpol_out; |
| 1321 | |
| 1322 | /* |
| 1323 | * Lock the VMAs before scanning for pages to migrate, |
| 1324 | * to ensure we don't miss a concurrently inserted page. |
| 1325 | */ |
| 1326 | nr_failed = queue_pages_range(mm, start, end, nmask, |
| 1327 | flags | MPOL_MF_INVERT | MPOL_MF_WRLOCK, &pagelist); |
| 1328 | |
| 1329 | if (nr_failed < 0) { |
| 1330 | err = nr_failed; |
| 1331 | nr_failed = 0; |
| 1332 | } else { |
| 1333 | vma_iter_init(&vmi, mm, start); |
| 1334 | prev = vma_prev(&vmi); |
| 1335 | for_each_vma_range(vmi, vma, end) { |
| 1336 | err = mbind_range(&vmi, vma, &prev, start, end, new); |
| 1337 | if (err) |
| 1338 | break; |
| 1339 | } |
| 1340 | } |
| 1341 | |
| 1342 | if (!err && !list_empty(&pagelist)) { |
| 1343 | /* Convert MPOL_DEFAULT's NULL to task or default policy */ |
| 1344 | if (!new) { |
| 1345 | new = get_task_policy(current); |
| 1346 | mpol_get(new); |
| 1347 | } |
| 1348 | mmpol.pol = new; |
| 1349 | mmpol.ilx = 0; |
| 1350 | |
| 1351 | /* |
| 1352 | * In the interleaved case, attempt to allocate on exactly the |
| 1353 | * targeted nodes, for the first VMA to be migrated; for later |
| 1354 | * VMAs, the nodes will still be interleaved from the targeted |
| 1355 | * nodemask, but one by one may be selected differently. |
| 1356 | */ |
| 1357 | if (new->mode == MPOL_INTERLEAVE || |
| 1358 | new->mode == MPOL_WEIGHTED_INTERLEAVE) { |
| 1359 | struct folio *folio; |
| 1360 | unsigned int order; |
| 1361 | unsigned long addr = -EFAULT; |
| 1362 | |
| 1363 | list_for_each_entry(folio, &pagelist, lru) { |
| 1364 | if (!folio_test_ksm(folio)) |
| 1365 | break; |
| 1366 | } |
| 1367 | if (!list_entry_is_head(folio, &pagelist, lru)) { |
| 1368 | vma_iter_init(&vmi, mm, start); |
| 1369 | for_each_vma_range(vmi, vma, end) { |
| 1370 | addr = page_address_in_vma( |
| 1371 | folio_page(folio, 0), vma); |
| 1372 | if (addr != -EFAULT) |
| 1373 | break; |
| 1374 | } |
| 1375 | } |
| 1376 | if (addr != -EFAULT) { |
| 1377 | order = folio_order(folio); |
| 1378 | /* We already know the pol, but not the ilx */ |
| 1379 | mpol_cond_put(get_vma_policy(vma, addr, order, |
| 1380 | &mmpol.ilx)); |
| 1381 | /* Set base from which to increment by index */ |
| 1382 | mmpol.ilx -= folio->index >> order; |
| 1383 | } |
| 1384 | } |
| 1385 | } |
| 1386 | |
| 1387 | mmap_write_unlock(mm); |
| 1388 | |
| 1389 | if (!err && !list_empty(&pagelist)) { |
| 1390 | nr_failed |= migrate_pages(&pagelist, |
| 1391 | alloc_migration_target_by_mpol, NULL, |
| 1392 | (unsigned long)&mmpol, MIGRATE_SYNC, |
| 1393 | MR_MEMPOLICY_MBIND, NULL); |
| 1394 | } |
| 1395 | |
| 1396 | if (nr_failed && (flags & MPOL_MF_STRICT)) |
| 1397 | err = -EIO; |
| 1398 | if (!list_empty(&pagelist)) |
| 1399 | putback_movable_pages(&pagelist); |
| 1400 | mpol_out: |
| 1401 | mpol_put(new); |
| 1402 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
| 1403 | lru_cache_enable(); |
| 1404 | return err; |
| 1405 | } |
| 1406 | |
| 1407 | /* |
| 1408 | * User space interface with variable sized bitmaps for nodelists. |
| 1409 | */ |
| 1410 | static int get_bitmap(unsigned long *mask, const unsigned long __user *nmask, |
| 1411 | unsigned long maxnode) |
| 1412 | { |
| 1413 | unsigned long nlongs = BITS_TO_LONGS(maxnode); |
| 1414 | int ret; |
| 1415 | |
| 1416 | if (in_compat_syscall()) |
| 1417 | ret = compat_get_bitmap(mask, |
| 1418 | (const compat_ulong_t __user *)nmask, |
| 1419 | maxnode); |
| 1420 | else |
| 1421 | ret = copy_from_user(mask, nmask, |
| 1422 | nlongs * sizeof(unsigned long)); |
| 1423 | |
| 1424 | if (ret) |
| 1425 | return -EFAULT; |
| 1426 | |
| 1427 | if (maxnode % BITS_PER_LONG) |
| 1428 | mask[nlongs - 1] &= (1UL << (maxnode % BITS_PER_LONG)) - 1; |
| 1429 | |
| 1430 | return 0; |
| 1431 | } |
| 1432 | |
| 1433 | /* Copy a node mask from user space. */ |
| 1434 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, |
| 1435 | unsigned long maxnode) |
| 1436 | { |
| 1437 | --maxnode; |
| 1438 | nodes_clear(*nodes); |
| 1439 | if (maxnode == 0 || !nmask) |
| 1440 | return 0; |
| 1441 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) |
| 1442 | return -EINVAL; |
| 1443 | |
| 1444 | /* |
| 1445 | * When the user specified more nodes than supported just check |
| 1446 | * if the non supported part is all zero, one word at a time, |
| 1447 | * starting at the end. |
| 1448 | */ |
| 1449 | while (maxnode > MAX_NUMNODES) { |
| 1450 | unsigned long bits = min_t(unsigned long, maxnode, BITS_PER_LONG); |
| 1451 | unsigned long t; |
| 1452 | |
| 1453 | if (get_bitmap(&t, &nmask[(maxnode - 1) / BITS_PER_LONG], bits)) |
| 1454 | return -EFAULT; |
| 1455 | |
| 1456 | if (maxnode - bits >= MAX_NUMNODES) { |
| 1457 | maxnode -= bits; |
| 1458 | } else { |
| 1459 | maxnode = MAX_NUMNODES; |
| 1460 | t &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1); |
| 1461 | } |
| 1462 | if (t) |
| 1463 | return -EINVAL; |
| 1464 | } |
| 1465 | |
| 1466 | return get_bitmap(nodes_addr(*nodes), nmask, maxnode); |
| 1467 | } |
| 1468 | |
| 1469 | /* Copy a kernel node mask to user space */ |
| 1470 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, |
| 1471 | nodemask_t *nodes) |
| 1472 | { |
| 1473 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; |
| 1474 | unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long); |
| 1475 | bool compat = in_compat_syscall(); |
| 1476 | |
| 1477 | if (compat) |
| 1478 | nbytes = BITS_TO_COMPAT_LONGS(nr_node_ids) * sizeof(compat_long_t); |
| 1479 | |
| 1480 | if (copy > nbytes) { |
| 1481 | if (copy > PAGE_SIZE) |
| 1482 | return -EINVAL; |
| 1483 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) |
| 1484 | return -EFAULT; |
| 1485 | copy = nbytes; |
| 1486 | maxnode = nr_node_ids; |
| 1487 | } |
| 1488 | |
| 1489 | if (compat) |
| 1490 | return compat_put_bitmap((compat_ulong_t __user *)mask, |
| 1491 | nodes_addr(*nodes), maxnode); |
| 1492 | |
| 1493 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; |
| 1494 | } |
| 1495 | |
| 1496 | /* Basic parameter sanity check used by both mbind() and set_mempolicy() */ |
| 1497 | static inline int sanitize_mpol_flags(int *mode, unsigned short *flags) |
| 1498 | { |
| 1499 | *flags = *mode & MPOL_MODE_FLAGS; |
| 1500 | *mode &= ~MPOL_MODE_FLAGS; |
| 1501 | |
| 1502 | if ((unsigned int)(*mode) >= MPOL_MAX) |
| 1503 | return -EINVAL; |
| 1504 | if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES)) |
| 1505 | return -EINVAL; |
| 1506 | if (*flags & MPOL_F_NUMA_BALANCING) { |
| 1507 | if (*mode == MPOL_BIND || *mode == MPOL_PREFERRED_MANY) |
| 1508 | *flags |= (MPOL_F_MOF | MPOL_F_MORON); |
| 1509 | else |
| 1510 | return -EINVAL; |
| 1511 | } |
| 1512 | return 0; |
| 1513 | } |
| 1514 | |
| 1515 | static long kernel_mbind(unsigned long start, unsigned long len, |
| 1516 | unsigned long mode, const unsigned long __user *nmask, |
| 1517 | unsigned long maxnode, unsigned int flags) |
| 1518 | { |
| 1519 | unsigned short mode_flags; |
| 1520 | nodemask_t nodes; |
| 1521 | int lmode = mode; |
| 1522 | int err; |
| 1523 | |
| 1524 | start = untagged_addr(start); |
| 1525 | err = sanitize_mpol_flags(&lmode, &mode_flags); |
| 1526 | if (err) |
| 1527 | return err; |
| 1528 | |
| 1529 | err = get_nodes(&nodes, nmask, maxnode); |
| 1530 | if (err) |
| 1531 | return err; |
| 1532 | |
| 1533 | return do_mbind(start, len, lmode, mode_flags, &nodes, flags); |
| 1534 | } |
| 1535 | |
| 1536 | SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, len, |
| 1537 | unsigned long, home_node, unsigned long, flags) |
| 1538 | { |
| 1539 | struct mm_struct *mm = current->mm; |
| 1540 | struct vm_area_struct *vma, *prev; |
| 1541 | struct mempolicy *new, *old; |
| 1542 | unsigned long end; |
| 1543 | int err = -ENOENT; |
| 1544 | VMA_ITERATOR(vmi, mm, start); |
| 1545 | |
| 1546 | start = untagged_addr(start); |
| 1547 | if (start & ~PAGE_MASK) |
| 1548 | return -EINVAL; |
| 1549 | /* |
| 1550 | * flags is used for future extension if any. |
| 1551 | */ |
| 1552 | if (flags != 0) |
| 1553 | return -EINVAL; |
| 1554 | |
| 1555 | /* |
| 1556 | * Check home_node is online to avoid accessing uninitialized |
| 1557 | * NODE_DATA. |
| 1558 | */ |
| 1559 | if (home_node >= MAX_NUMNODES || !node_online(home_node)) |
| 1560 | return -EINVAL; |
| 1561 | |
| 1562 | len = PAGE_ALIGN(len); |
| 1563 | end = start + len; |
| 1564 | |
| 1565 | if (end < start) |
| 1566 | return -EINVAL; |
| 1567 | if (end == start) |
| 1568 | return 0; |
| 1569 | mmap_write_lock(mm); |
| 1570 | prev = vma_prev(&vmi); |
| 1571 | for_each_vma_range(vmi, vma, end) { |
| 1572 | /* |
| 1573 | * If any vma in the range got policy other than MPOL_BIND |
| 1574 | * or MPOL_PREFERRED_MANY we return error. We don't reset |
| 1575 | * the home node for vmas we already updated before. |
| 1576 | */ |
| 1577 | old = vma_policy(vma); |
| 1578 | if (!old) { |
| 1579 | prev = vma; |
| 1580 | continue; |
| 1581 | } |
| 1582 | if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) { |
| 1583 | err = -EOPNOTSUPP; |
| 1584 | break; |
| 1585 | } |
| 1586 | new = mpol_dup(old); |
| 1587 | if (IS_ERR(new)) { |
| 1588 | err = PTR_ERR(new); |
| 1589 | break; |
| 1590 | } |
| 1591 | |
| 1592 | vma_start_write(vma); |
| 1593 | new->home_node = home_node; |
| 1594 | err = mbind_range(&vmi, vma, &prev, start, end, new); |
| 1595 | mpol_put(new); |
| 1596 | if (err) |
| 1597 | break; |
| 1598 | } |
| 1599 | mmap_write_unlock(mm); |
| 1600 | return err; |
| 1601 | } |
| 1602 | |
| 1603 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, |
| 1604 | unsigned long, mode, const unsigned long __user *, nmask, |
| 1605 | unsigned long, maxnode, unsigned int, flags) |
| 1606 | { |
| 1607 | return kernel_mbind(start, len, mode, nmask, maxnode, flags); |
| 1608 | } |
| 1609 | |
| 1610 | /* Set the process memory policy */ |
| 1611 | static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask, |
| 1612 | unsigned long maxnode) |
| 1613 | { |
| 1614 | unsigned short mode_flags; |
| 1615 | nodemask_t nodes; |
| 1616 | int lmode = mode; |
| 1617 | int err; |
| 1618 | |
| 1619 | err = sanitize_mpol_flags(&lmode, &mode_flags); |
| 1620 | if (err) |
| 1621 | return err; |
| 1622 | |
| 1623 | err = get_nodes(&nodes, nmask, maxnode); |
| 1624 | if (err) |
| 1625 | return err; |
| 1626 | |
| 1627 | return do_set_mempolicy(lmode, mode_flags, &nodes); |
| 1628 | } |
| 1629 | |
| 1630 | SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask, |
| 1631 | unsigned long, maxnode) |
| 1632 | { |
| 1633 | return kernel_set_mempolicy(mode, nmask, maxnode); |
| 1634 | } |
| 1635 | |
| 1636 | static int kernel_migrate_pages(pid_t pid, unsigned long maxnode, |
| 1637 | const unsigned long __user *old_nodes, |
| 1638 | const unsigned long __user *new_nodes) |
| 1639 | { |
| 1640 | struct mm_struct *mm = NULL; |
| 1641 | struct task_struct *task; |
| 1642 | nodemask_t task_nodes; |
| 1643 | int err; |
| 1644 | nodemask_t *old; |
| 1645 | nodemask_t *new; |
| 1646 | NODEMASK_SCRATCH(scratch); |
| 1647 | |
| 1648 | if (!scratch) |
| 1649 | return -ENOMEM; |
| 1650 | |
| 1651 | old = &scratch->mask1; |
| 1652 | new = &scratch->mask2; |
| 1653 | |
| 1654 | err = get_nodes(old, old_nodes, maxnode); |
| 1655 | if (err) |
| 1656 | goto out; |
| 1657 | |
| 1658 | err = get_nodes(new, new_nodes, maxnode); |
| 1659 | if (err) |
| 1660 | goto out; |
| 1661 | |
| 1662 | /* Find the mm_struct */ |
| 1663 | rcu_read_lock(); |
| 1664 | task = pid ? find_task_by_vpid(pid) : current; |
| 1665 | if (!task) { |
| 1666 | rcu_read_unlock(); |
| 1667 | err = -ESRCH; |
| 1668 | goto out; |
| 1669 | } |
| 1670 | get_task_struct(task); |
| 1671 | |
| 1672 | err = -EINVAL; |
| 1673 | |
| 1674 | /* |
| 1675 | * Check if this process has the right to modify the specified process. |
| 1676 | * Use the regular "ptrace_may_access()" checks. |
| 1677 | */ |
| 1678 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) { |
| 1679 | rcu_read_unlock(); |
| 1680 | err = -EPERM; |
| 1681 | goto out_put; |
| 1682 | } |
| 1683 | rcu_read_unlock(); |
| 1684 | |
| 1685 | task_nodes = cpuset_mems_allowed(task); |
| 1686 | /* Is the user allowed to access the target nodes? */ |
| 1687 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { |
| 1688 | err = -EPERM; |
| 1689 | goto out_put; |
| 1690 | } |
| 1691 | |
| 1692 | task_nodes = cpuset_mems_allowed(current); |
| 1693 | nodes_and(*new, *new, task_nodes); |
| 1694 | if (nodes_empty(*new)) |
| 1695 | goto out_put; |
| 1696 | |
| 1697 | err = security_task_movememory(task); |
| 1698 | if (err) |
| 1699 | goto out_put; |
| 1700 | |
| 1701 | mm = get_task_mm(task); |
| 1702 | put_task_struct(task); |
| 1703 | |
| 1704 | if (!mm) { |
| 1705 | err = -EINVAL; |
| 1706 | goto out; |
| 1707 | } |
| 1708 | |
| 1709 | err = do_migrate_pages(mm, old, new, |
| 1710 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); |
| 1711 | |
| 1712 | mmput(mm); |
| 1713 | out: |
| 1714 | NODEMASK_SCRATCH_FREE(scratch); |
| 1715 | |
| 1716 | return err; |
| 1717 | |
| 1718 | out_put: |
| 1719 | put_task_struct(task); |
| 1720 | goto out; |
| 1721 | } |
| 1722 | |
| 1723 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, |
| 1724 | const unsigned long __user *, old_nodes, |
| 1725 | const unsigned long __user *, new_nodes) |
| 1726 | { |
| 1727 | return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes); |
| 1728 | } |
| 1729 | |
| 1730 | /* Retrieve NUMA policy */ |
| 1731 | static int kernel_get_mempolicy(int __user *policy, |
| 1732 | unsigned long __user *nmask, |
| 1733 | unsigned long maxnode, |
| 1734 | unsigned long addr, |
| 1735 | unsigned long flags) |
| 1736 | { |
| 1737 | int err; |
| 1738 | int pval; |
| 1739 | nodemask_t nodes; |
| 1740 | |
| 1741 | if (nmask != NULL && maxnode < nr_node_ids) |
| 1742 | return -EINVAL; |
| 1743 | |
| 1744 | addr = untagged_addr(addr); |
| 1745 | |
| 1746 | err = do_get_mempolicy(&pval, &nodes, addr, flags); |
| 1747 | |
| 1748 | if (err) |
| 1749 | return err; |
| 1750 | |
| 1751 | if (policy && put_user(pval, policy)) |
| 1752 | return -EFAULT; |
| 1753 | |
| 1754 | if (nmask) |
| 1755 | err = copy_nodes_to_user(nmask, maxnode, &nodes); |
| 1756 | |
| 1757 | return err; |
| 1758 | } |
| 1759 | |
| 1760 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
| 1761 | unsigned long __user *, nmask, unsigned long, maxnode, |
| 1762 | unsigned long, addr, unsigned long, flags) |
| 1763 | { |
| 1764 | return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags); |
| 1765 | } |
| 1766 | |
| 1767 | bool vma_migratable(struct vm_area_struct *vma) |
| 1768 | { |
| 1769 | if (vma->vm_flags & (VM_IO | VM_PFNMAP)) |
| 1770 | return false; |
| 1771 | |
| 1772 | /* |
| 1773 | * DAX device mappings require predictable access latency, so avoid |
| 1774 | * incurring periodic faults. |
| 1775 | */ |
| 1776 | if (vma_is_dax(vma)) |
| 1777 | return false; |
| 1778 | |
| 1779 | if (is_vm_hugetlb_page(vma) && |
| 1780 | !hugepage_migration_supported(hstate_vma(vma))) |
| 1781 | return false; |
| 1782 | |
| 1783 | /* |
| 1784 | * Migration allocates pages in the highest zone. If we cannot |
| 1785 | * do so then migration (at least from node to node) is not |
| 1786 | * possible. |
| 1787 | */ |
| 1788 | if (vma->vm_file && |
| 1789 | gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping)) |
| 1790 | < policy_zone) |
| 1791 | return false; |
| 1792 | return true; |
| 1793 | } |
| 1794 | |
| 1795 | struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, |
| 1796 | unsigned long addr, pgoff_t *ilx) |
| 1797 | { |
| 1798 | *ilx = 0; |
| 1799 | return (vma->vm_ops && vma->vm_ops->get_policy) ? |
| 1800 | vma->vm_ops->get_policy(vma, addr, ilx) : vma->vm_policy; |
| 1801 | } |
| 1802 | |
| 1803 | /* |
| 1804 | * get_vma_policy(@vma, @addr, @order, @ilx) |
| 1805 | * @vma: virtual memory area whose policy is sought |
| 1806 | * @addr: address in @vma for shared policy lookup |
| 1807 | * @order: 0, or appropriate huge_page_order for interleaving |
| 1808 | * @ilx: interleave index (output), for use only when MPOL_INTERLEAVE or |
| 1809 | * MPOL_WEIGHTED_INTERLEAVE |
| 1810 | * |
| 1811 | * Returns effective policy for a VMA at specified address. |
| 1812 | * Falls back to current->mempolicy or system default policy, as necessary. |
| 1813 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference |
| 1814 | * count--added by the get_policy() vm_op, as appropriate--to protect against |
| 1815 | * freeing by another task. It is the caller's responsibility to free the |
| 1816 | * extra reference for shared policies. |
| 1817 | */ |
| 1818 | struct mempolicy *get_vma_policy(struct vm_area_struct *vma, |
| 1819 | unsigned long addr, int order, pgoff_t *ilx) |
| 1820 | { |
| 1821 | struct mempolicy *pol; |
| 1822 | |
| 1823 | pol = __get_vma_policy(vma, addr, ilx); |
| 1824 | if (!pol) |
| 1825 | pol = get_task_policy(current); |
| 1826 | if (pol->mode == MPOL_INTERLEAVE || |
| 1827 | pol->mode == MPOL_WEIGHTED_INTERLEAVE) { |
| 1828 | *ilx += vma->vm_pgoff >> order; |
| 1829 | *ilx += (addr - vma->vm_start) >> (PAGE_SHIFT + order); |
| 1830 | } |
| 1831 | return pol; |
| 1832 | } |
| 1833 | |
| 1834 | bool vma_policy_mof(struct vm_area_struct *vma) |
| 1835 | { |
| 1836 | struct mempolicy *pol; |
| 1837 | |
| 1838 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
| 1839 | bool ret = false; |
| 1840 | pgoff_t ilx; /* ignored here */ |
| 1841 | |
| 1842 | pol = vma->vm_ops->get_policy(vma, vma->vm_start, &ilx); |
| 1843 | if (pol && (pol->flags & MPOL_F_MOF)) |
| 1844 | ret = true; |
| 1845 | mpol_cond_put(pol); |
| 1846 | |
| 1847 | return ret; |
| 1848 | } |
| 1849 | |
| 1850 | pol = vma->vm_policy; |
| 1851 | if (!pol) |
| 1852 | pol = get_task_policy(current); |
| 1853 | |
| 1854 | return pol->flags & MPOL_F_MOF; |
| 1855 | } |
| 1856 | |
| 1857 | bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone) |
| 1858 | { |
| 1859 | enum zone_type dynamic_policy_zone = policy_zone; |
| 1860 | |
| 1861 | BUG_ON(dynamic_policy_zone == ZONE_MOVABLE); |
| 1862 | |
| 1863 | /* |
| 1864 | * if policy->nodes has movable memory only, |
| 1865 | * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only. |
| 1866 | * |
| 1867 | * policy->nodes is intersect with node_states[N_MEMORY]. |
| 1868 | * so if the following test fails, it implies |
| 1869 | * policy->nodes has movable memory only. |
| 1870 | */ |
| 1871 | if (!nodes_intersects(policy->nodes, node_states[N_HIGH_MEMORY])) |
| 1872 | dynamic_policy_zone = ZONE_MOVABLE; |
| 1873 | |
| 1874 | return zone >= dynamic_policy_zone; |
| 1875 | } |
| 1876 | |
| 1877 | static unsigned int weighted_interleave_nodes(struct mempolicy *policy) |
| 1878 | { |
| 1879 | unsigned int node; |
| 1880 | unsigned int cpuset_mems_cookie; |
| 1881 | |
| 1882 | retry: |
| 1883 | /* to prevent miscount use tsk->mems_allowed_seq to detect rebind */ |
| 1884 | cpuset_mems_cookie = read_mems_allowed_begin(); |
| 1885 | node = current->il_prev; |
| 1886 | if (!current->il_weight || !node_isset(node, policy->nodes)) { |
| 1887 | node = next_node_in(node, policy->nodes); |
| 1888 | if (read_mems_allowed_retry(cpuset_mems_cookie)) |
| 1889 | goto retry; |
| 1890 | if (node == MAX_NUMNODES) |
| 1891 | return node; |
| 1892 | current->il_prev = node; |
| 1893 | current->il_weight = get_il_weight(node); |
| 1894 | } |
| 1895 | current->il_weight--; |
| 1896 | return node; |
| 1897 | } |
| 1898 | |
| 1899 | /* Do dynamic interleaving for a process */ |
| 1900 | static unsigned int interleave_nodes(struct mempolicy *policy) |
| 1901 | { |
| 1902 | unsigned int nid; |
| 1903 | unsigned int cpuset_mems_cookie; |
| 1904 | |
| 1905 | /* to prevent miscount, use tsk->mems_allowed_seq to detect rebind */ |
| 1906 | do { |
| 1907 | cpuset_mems_cookie = read_mems_allowed_begin(); |
| 1908 | nid = next_node_in(current->il_prev, policy->nodes); |
| 1909 | } while (read_mems_allowed_retry(cpuset_mems_cookie)); |
| 1910 | |
| 1911 | if (nid < MAX_NUMNODES) |
| 1912 | current->il_prev = nid; |
| 1913 | return nid; |
| 1914 | } |
| 1915 | |
| 1916 | /* |
| 1917 | * Depending on the memory policy provide a node from which to allocate the |
| 1918 | * next slab entry. |
| 1919 | */ |
| 1920 | unsigned int mempolicy_slab_node(void) |
| 1921 | { |
| 1922 | struct mempolicy *policy; |
| 1923 | int node = numa_mem_id(); |
| 1924 | |
| 1925 | if (!in_task()) |
| 1926 | return node; |
| 1927 | |
| 1928 | policy = current->mempolicy; |
| 1929 | if (!policy) |
| 1930 | return node; |
| 1931 | |
| 1932 | switch (policy->mode) { |
| 1933 | case MPOL_PREFERRED: |
| 1934 | return first_node(policy->nodes); |
| 1935 | |
| 1936 | case MPOL_INTERLEAVE: |
| 1937 | return interleave_nodes(policy); |
| 1938 | |
| 1939 | case MPOL_WEIGHTED_INTERLEAVE: |
| 1940 | return weighted_interleave_nodes(policy); |
| 1941 | |
| 1942 | case MPOL_BIND: |
| 1943 | case MPOL_PREFERRED_MANY: |
| 1944 | { |
| 1945 | struct zoneref *z; |
| 1946 | |
| 1947 | /* |
| 1948 | * Follow bind policy behavior and start allocation at the |
| 1949 | * first node. |
| 1950 | */ |
| 1951 | struct zonelist *zonelist; |
| 1952 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); |
| 1953 | zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK]; |
| 1954 | z = first_zones_zonelist(zonelist, highest_zoneidx, |
| 1955 | &policy->nodes); |
| 1956 | return z->zone ? zone_to_nid(z->zone) : node; |
| 1957 | } |
| 1958 | case MPOL_LOCAL: |
| 1959 | return node; |
| 1960 | |
| 1961 | default: |
| 1962 | BUG(); |
| 1963 | } |
| 1964 | } |
| 1965 | |
| 1966 | static unsigned int read_once_policy_nodemask(struct mempolicy *pol, |
| 1967 | nodemask_t *mask) |
| 1968 | { |
| 1969 | /* |
| 1970 | * barrier stabilizes the nodemask locally so that it can be iterated |
| 1971 | * over safely without concern for changes. Allocators validate node |
| 1972 | * selection does not violate mems_allowed, so this is safe. |
| 1973 | */ |
| 1974 | barrier(); |
| 1975 | memcpy(mask, &pol->nodes, sizeof(nodemask_t)); |
| 1976 | barrier(); |
| 1977 | return nodes_weight(*mask); |
| 1978 | } |
| 1979 | |
| 1980 | static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx) |
| 1981 | { |
| 1982 | nodemask_t nodemask; |
| 1983 | unsigned int target, nr_nodes; |
| 1984 | u8 *table; |
| 1985 | unsigned int weight_total = 0; |
| 1986 | u8 weight; |
| 1987 | int nid; |
| 1988 | |
| 1989 | nr_nodes = read_once_policy_nodemask(pol, &nodemask); |
| 1990 | if (!nr_nodes) |
| 1991 | return numa_node_id(); |
| 1992 | |
| 1993 | rcu_read_lock(); |
| 1994 | table = rcu_dereference(iw_table); |
| 1995 | /* calculate the total weight */ |
| 1996 | for_each_node_mask(nid, nodemask) { |
| 1997 | /* detect system default usage */ |
| 1998 | weight = table ? table[nid] : 1; |
| 1999 | weight = weight ? weight : 1; |
| 2000 | weight_total += weight; |
| 2001 | } |
| 2002 | |
| 2003 | /* Calculate the node offset based on totals */ |
| 2004 | target = ilx % weight_total; |
| 2005 | nid = first_node(nodemask); |
| 2006 | while (target) { |
| 2007 | /* detect system default usage */ |
| 2008 | weight = table ? table[nid] : 1; |
| 2009 | weight = weight ? weight : 1; |
| 2010 | if (target < weight) |
| 2011 | break; |
| 2012 | target -= weight; |
| 2013 | nid = next_node_in(nid, nodemask); |
| 2014 | } |
| 2015 | rcu_read_unlock(); |
| 2016 | return nid; |
| 2017 | } |
| 2018 | |
| 2019 | /* |
| 2020 | * Do static interleaving for interleave index @ilx. Returns the ilx'th |
| 2021 | * node in pol->nodes (starting from ilx=0), wrapping around if ilx |
| 2022 | * exceeds the number of present nodes. |
| 2023 | */ |
| 2024 | static unsigned int interleave_nid(struct mempolicy *pol, pgoff_t ilx) |
| 2025 | { |
| 2026 | nodemask_t nodemask; |
| 2027 | unsigned int target, nnodes; |
| 2028 | int i; |
| 2029 | int nid; |
| 2030 | |
| 2031 | nnodes = read_once_policy_nodemask(pol, &nodemask); |
| 2032 | if (!nnodes) |
| 2033 | return numa_node_id(); |
| 2034 | target = ilx % nnodes; |
| 2035 | nid = first_node(nodemask); |
| 2036 | for (i = 0; i < target; i++) |
| 2037 | nid = next_node(nid, nodemask); |
| 2038 | return nid; |
| 2039 | } |
| 2040 | |
| 2041 | /* |
| 2042 | * Return a nodemask representing a mempolicy for filtering nodes for |
| 2043 | * page allocation, together with preferred node id (or the input node id). |
| 2044 | */ |
| 2045 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *pol, |
| 2046 | pgoff_t ilx, int *nid) |
| 2047 | { |
| 2048 | nodemask_t *nodemask = NULL; |
| 2049 | |
| 2050 | switch (pol->mode) { |
| 2051 | case MPOL_PREFERRED: |
| 2052 | /* Override input node id */ |
| 2053 | *nid = first_node(pol->nodes); |
| 2054 | break; |
| 2055 | case MPOL_PREFERRED_MANY: |
| 2056 | nodemask = &pol->nodes; |
| 2057 | if (pol->home_node != NUMA_NO_NODE) |
| 2058 | *nid = pol->home_node; |
| 2059 | break; |
| 2060 | case MPOL_BIND: |
| 2061 | /* Restrict to nodemask (but not on lower zones) */ |
| 2062 | if (apply_policy_zone(pol, gfp_zone(gfp)) && |
| 2063 | cpuset_nodemask_valid_mems_allowed(&pol->nodes)) |
| 2064 | nodemask = &pol->nodes; |
| 2065 | if (pol->home_node != NUMA_NO_NODE) |
| 2066 | *nid = pol->home_node; |
| 2067 | /* |
| 2068 | * __GFP_THISNODE shouldn't even be used with the bind policy |
| 2069 | * because we might easily break the expectation to stay on the |
| 2070 | * requested node and not break the policy. |
| 2071 | */ |
| 2072 | WARN_ON_ONCE(gfp & __GFP_THISNODE); |
| 2073 | break; |
| 2074 | case MPOL_INTERLEAVE: |
| 2075 | /* Override input node id */ |
| 2076 | *nid = (ilx == NO_INTERLEAVE_INDEX) ? |
| 2077 | interleave_nodes(pol) : interleave_nid(pol, ilx); |
| 2078 | break; |
| 2079 | case MPOL_WEIGHTED_INTERLEAVE: |
| 2080 | *nid = (ilx == NO_INTERLEAVE_INDEX) ? |
| 2081 | weighted_interleave_nodes(pol) : |
| 2082 | weighted_interleave_nid(pol, ilx); |
| 2083 | break; |
| 2084 | } |
| 2085 | |
| 2086 | return nodemask; |
| 2087 | } |
| 2088 | |
| 2089 | #ifdef CONFIG_HUGETLBFS |
| 2090 | /* |
| 2091 | * huge_node(@vma, @addr, @gfp_flags, @mpol) |
| 2092 | * @vma: virtual memory area whose policy is sought |
| 2093 | * @addr: address in @vma for shared policy lookup and interleave policy |
| 2094 | * @gfp_flags: for requested zone |
| 2095 | * @mpol: pointer to mempolicy pointer for reference counted mempolicy |
| 2096 | * @nodemask: pointer to nodemask pointer for 'bind' and 'prefer-many' policy |
| 2097 | * |
| 2098 | * Returns a nid suitable for a huge page allocation and a pointer |
| 2099 | * to the struct mempolicy for conditional unref after allocation. |
| 2100 | * If the effective policy is 'bind' or 'prefer-many', returns a pointer |
| 2101 | * to the mempolicy's @nodemask for filtering the zonelist. |
| 2102 | */ |
| 2103 | int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags, |
| 2104 | struct mempolicy **mpol, nodemask_t **nodemask) |
| 2105 | { |
| 2106 | pgoff_t ilx; |
| 2107 | int nid; |
| 2108 | |
| 2109 | nid = numa_node_id(); |
| 2110 | *mpol = get_vma_policy(vma, addr, hstate_vma(vma)->order, &ilx); |
| 2111 | *nodemask = policy_nodemask(gfp_flags, *mpol, ilx, &nid); |
| 2112 | return nid; |
| 2113 | } |
| 2114 | |
| 2115 | /* |
| 2116 | * init_nodemask_of_mempolicy |
| 2117 | * |
| 2118 | * If the current task's mempolicy is "default" [NULL], return 'false' |
| 2119 | * to indicate default policy. Otherwise, extract the policy nodemask |
| 2120 | * for 'bind' or 'interleave' policy into the argument nodemask, or |
| 2121 | * initialize the argument nodemask to contain the single node for |
| 2122 | * 'preferred' or 'local' policy and return 'true' to indicate presence |
| 2123 | * of non-default mempolicy. |
| 2124 | * |
| 2125 | * We don't bother with reference counting the mempolicy [mpol_get/put] |
| 2126 | * because the current task is examining it's own mempolicy and a task's |
| 2127 | * mempolicy is only ever changed by the task itself. |
| 2128 | * |
| 2129 | * N.B., it is the caller's responsibility to free a returned nodemask. |
| 2130 | */ |
| 2131 | bool init_nodemask_of_mempolicy(nodemask_t *mask) |
| 2132 | { |
| 2133 | struct mempolicy *mempolicy; |
| 2134 | |
| 2135 | if (!(mask && current->mempolicy)) |
| 2136 | return false; |
| 2137 | |
| 2138 | task_lock(current); |
| 2139 | mempolicy = current->mempolicy; |
| 2140 | switch (mempolicy->mode) { |
| 2141 | case MPOL_PREFERRED: |
| 2142 | case MPOL_PREFERRED_MANY: |
| 2143 | case MPOL_BIND: |
| 2144 | case MPOL_INTERLEAVE: |
| 2145 | case MPOL_WEIGHTED_INTERLEAVE: |
| 2146 | *mask = mempolicy->nodes; |
| 2147 | break; |
| 2148 | |
| 2149 | case MPOL_LOCAL: |
| 2150 | init_nodemask_of_node(mask, numa_node_id()); |
| 2151 | break; |
| 2152 | |
| 2153 | default: |
| 2154 | BUG(); |
| 2155 | } |
| 2156 | task_unlock(current); |
| 2157 | |
| 2158 | return true; |
| 2159 | } |
| 2160 | #endif |
| 2161 | |
| 2162 | /* |
| 2163 | * mempolicy_in_oom_domain |
| 2164 | * |
| 2165 | * If tsk's mempolicy is "bind", check for intersection between mask and |
| 2166 | * the policy nodemask. Otherwise, return true for all other policies |
| 2167 | * including "interleave", as a tsk with "interleave" policy may have |
| 2168 | * memory allocated from all nodes in system. |
| 2169 | * |
| 2170 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. |
| 2171 | */ |
| 2172 | bool mempolicy_in_oom_domain(struct task_struct *tsk, |
| 2173 | const nodemask_t *mask) |
| 2174 | { |
| 2175 | struct mempolicy *mempolicy; |
| 2176 | bool ret = true; |
| 2177 | |
| 2178 | if (!mask) |
| 2179 | return ret; |
| 2180 | |
| 2181 | task_lock(tsk); |
| 2182 | mempolicy = tsk->mempolicy; |
| 2183 | if (mempolicy && mempolicy->mode == MPOL_BIND) |
| 2184 | ret = nodes_intersects(mempolicy->nodes, *mask); |
| 2185 | task_unlock(tsk); |
| 2186 | |
| 2187 | return ret; |
| 2188 | } |
| 2189 | |
| 2190 | static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order, |
| 2191 | int nid, nodemask_t *nodemask) |
| 2192 | { |
| 2193 | struct page *page; |
| 2194 | gfp_t preferred_gfp; |
| 2195 | |
| 2196 | /* |
| 2197 | * This is a two pass approach. The first pass will only try the |
| 2198 | * preferred nodes but skip the direct reclaim and allow the |
| 2199 | * allocation to fail, while the second pass will try all the |
| 2200 | * nodes in system. |
| 2201 | */ |
| 2202 | preferred_gfp = gfp | __GFP_NOWARN; |
| 2203 | preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); |
| 2204 | page = __alloc_pages_noprof(preferred_gfp, order, nid, nodemask); |
| 2205 | if (!page) |
| 2206 | page = __alloc_pages_noprof(gfp, order, nid, NULL); |
| 2207 | |
| 2208 | return page; |
| 2209 | } |
| 2210 | |
| 2211 | /** |
| 2212 | * alloc_pages_mpol - Allocate pages according to NUMA mempolicy. |
| 2213 | * @gfp: GFP flags. |
| 2214 | * @order: Order of the page allocation. |
| 2215 | * @pol: Pointer to the NUMA mempolicy. |
| 2216 | * @ilx: Index for interleave mempolicy (also distinguishes alloc_pages()). |
| 2217 | * @nid: Preferred node (usually numa_node_id() but @mpol may override it). |
| 2218 | * |
| 2219 | * Return: The page on success or NULL if allocation fails. |
| 2220 | */ |
| 2221 | struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order, |
| 2222 | struct mempolicy *pol, pgoff_t ilx, int nid) |
| 2223 | { |
| 2224 | nodemask_t *nodemask; |
| 2225 | struct page *page; |
| 2226 | |
| 2227 | nodemask = policy_nodemask(gfp, pol, ilx, &nid); |
| 2228 | |
| 2229 | if (pol->mode == MPOL_PREFERRED_MANY) |
| 2230 | return alloc_pages_preferred_many(gfp, order, nid, nodemask); |
| 2231 | |
| 2232 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && |
| 2233 | /* filter "hugepage" allocation, unless from alloc_pages() */ |
| 2234 | order == HPAGE_PMD_ORDER && ilx != NO_INTERLEAVE_INDEX) { |
| 2235 | /* |
| 2236 | * For hugepage allocation and non-interleave policy which |
| 2237 | * allows the current node (or other explicitly preferred |
| 2238 | * node) we only try to allocate from the current/preferred |
| 2239 | * node and don't fall back to other nodes, as the cost of |
| 2240 | * remote accesses would likely offset THP benefits. |
| 2241 | * |
| 2242 | * If the policy is interleave or does not allow the current |
| 2243 | * node in its nodemask, we allocate the standard way. |
| 2244 | */ |
| 2245 | if (pol->mode != MPOL_INTERLEAVE && |
| 2246 | pol->mode != MPOL_WEIGHTED_INTERLEAVE && |
| 2247 | (!nodemask || node_isset(nid, *nodemask))) { |
| 2248 | /* |
| 2249 | * First, try to allocate THP only on local node, but |
| 2250 | * don't reclaim unnecessarily, just compact. |
| 2251 | */ |
| 2252 | page = __alloc_pages_node_noprof(nid, |
| 2253 | gfp | __GFP_THISNODE | __GFP_NORETRY, order); |
| 2254 | if (page || !(gfp & __GFP_DIRECT_RECLAIM)) |
| 2255 | return page; |
| 2256 | /* |
| 2257 | * If hugepage allocations are configured to always |
| 2258 | * synchronous compact or the vma has been madvised |
| 2259 | * to prefer hugepage backing, retry allowing remote |
| 2260 | * memory with both reclaim and compact as well. |
| 2261 | */ |
| 2262 | } |
| 2263 | } |
| 2264 | |
| 2265 | page = __alloc_pages_noprof(gfp, order, nid, nodemask); |
| 2266 | |
| 2267 | if (unlikely(pol->mode == MPOL_INTERLEAVE) && page) { |
| 2268 | /* skip NUMA_INTERLEAVE_HIT update if numa stats is disabled */ |
| 2269 | if (static_branch_likely(&vm_numa_stat_key) && |
| 2270 | page_to_nid(page) == nid) { |
| 2271 | preempt_disable(); |
| 2272 | __count_numa_event(page_zone(page), NUMA_INTERLEAVE_HIT); |
| 2273 | preempt_enable(); |
| 2274 | } |
| 2275 | } |
| 2276 | |
| 2277 | return page; |
| 2278 | } |
| 2279 | |
| 2280 | /** |
| 2281 | * vma_alloc_folio - Allocate a folio for a VMA. |
| 2282 | * @gfp: GFP flags. |
| 2283 | * @order: Order of the folio. |
| 2284 | * @vma: Pointer to VMA. |
| 2285 | * @addr: Virtual address of the allocation. Must be inside @vma. |
| 2286 | * @hugepage: Unused (was: For hugepages try only preferred node if possible). |
| 2287 | * |
| 2288 | * Allocate a folio for a specific address in @vma, using the appropriate |
| 2289 | * NUMA policy. The caller must hold the mmap_lock of the mm_struct of the |
| 2290 | * VMA to prevent it from going away. Should be used for all allocations |
| 2291 | * for folios that will be mapped into user space, excepting hugetlbfs, and |
| 2292 | * excepting where direct use of alloc_pages_mpol() is more appropriate. |
| 2293 | * |
| 2294 | * Return: The folio on success or NULL if allocation fails. |
| 2295 | */ |
| 2296 | struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct *vma, |
| 2297 | unsigned long addr, bool hugepage) |
| 2298 | { |
| 2299 | struct mempolicy *pol; |
| 2300 | pgoff_t ilx; |
| 2301 | struct page *page; |
| 2302 | |
| 2303 | pol = get_vma_policy(vma, addr, order, &ilx); |
| 2304 | page = alloc_pages_mpol_noprof(gfp | __GFP_COMP, order, |
| 2305 | pol, ilx, numa_node_id()); |
| 2306 | mpol_cond_put(pol); |
| 2307 | return page_rmappable_folio(page); |
| 2308 | } |
| 2309 | EXPORT_SYMBOL(vma_alloc_folio_noprof); |
| 2310 | |
| 2311 | /** |
| 2312 | * alloc_pages - Allocate pages. |
| 2313 | * @gfp: GFP flags. |
| 2314 | * @order: Power of two of number of pages to allocate. |
| 2315 | * |
| 2316 | * Allocate 1 << @order contiguous pages. The physical address of the |
| 2317 | * first page is naturally aligned (eg an order-3 allocation will be aligned |
| 2318 | * to a multiple of 8 * PAGE_SIZE bytes). The NUMA policy of the current |
| 2319 | * process is honoured when in process context. |
| 2320 | * |
| 2321 | * Context: Can be called from any context, providing the appropriate GFP |
| 2322 | * flags are used. |
| 2323 | * Return: The page on success or NULL if allocation fails. |
| 2324 | */ |
| 2325 | struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order) |
| 2326 | { |
| 2327 | struct mempolicy *pol = &default_policy; |
| 2328 | |
| 2329 | /* |
| 2330 | * No reference counting needed for current->mempolicy |
| 2331 | * nor system default_policy |
| 2332 | */ |
| 2333 | if (!in_interrupt() && !(gfp & __GFP_THISNODE)) |
| 2334 | pol = get_task_policy(current); |
| 2335 | |
| 2336 | return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX, |
| 2337 | numa_node_id()); |
| 2338 | } |
| 2339 | EXPORT_SYMBOL(alloc_pages_noprof); |
| 2340 | |
| 2341 | struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order) |
| 2342 | { |
| 2343 | return page_rmappable_folio(alloc_pages_noprof(gfp | __GFP_COMP, order)); |
| 2344 | } |
| 2345 | EXPORT_SYMBOL(folio_alloc_noprof); |
| 2346 | |
| 2347 | static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp, |
| 2348 | struct mempolicy *pol, unsigned long nr_pages, |
| 2349 | struct page **page_array) |
| 2350 | { |
| 2351 | int nodes; |
| 2352 | unsigned long nr_pages_per_node; |
| 2353 | int delta; |
| 2354 | int i; |
| 2355 | unsigned long nr_allocated; |
| 2356 | unsigned long total_allocated = 0; |
| 2357 | |
| 2358 | nodes = nodes_weight(pol->nodes); |
| 2359 | nr_pages_per_node = nr_pages / nodes; |
| 2360 | delta = nr_pages - nodes * nr_pages_per_node; |
| 2361 | |
| 2362 | for (i = 0; i < nodes; i++) { |
| 2363 | if (delta) { |
| 2364 | nr_allocated = alloc_pages_bulk_noprof(gfp, |
| 2365 | interleave_nodes(pol), NULL, |
| 2366 | nr_pages_per_node + 1, NULL, |
| 2367 | page_array); |
| 2368 | delta--; |
| 2369 | } else { |
| 2370 | nr_allocated = alloc_pages_bulk_noprof(gfp, |
| 2371 | interleave_nodes(pol), NULL, |
| 2372 | nr_pages_per_node, NULL, page_array); |
| 2373 | } |
| 2374 | |
| 2375 | page_array += nr_allocated; |
| 2376 | total_allocated += nr_allocated; |
| 2377 | } |
| 2378 | |
| 2379 | return total_allocated; |
| 2380 | } |
| 2381 | |
| 2382 | static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, |
| 2383 | struct mempolicy *pol, unsigned long nr_pages, |
| 2384 | struct page **page_array) |
| 2385 | { |
| 2386 | struct task_struct *me = current; |
| 2387 | unsigned int cpuset_mems_cookie; |
| 2388 | unsigned long total_allocated = 0; |
| 2389 | unsigned long nr_allocated = 0; |
| 2390 | unsigned long rounds; |
| 2391 | unsigned long node_pages, delta; |
| 2392 | u8 *table, *weights, weight; |
| 2393 | unsigned int weight_total = 0; |
| 2394 | unsigned long rem_pages = nr_pages; |
| 2395 | nodemask_t nodes; |
| 2396 | int nnodes, node; |
| 2397 | int resume_node = MAX_NUMNODES - 1; |
| 2398 | u8 resume_weight = 0; |
| 2399 | int prev_node; |
| 2400 | int i; |
| 2401 | |
| 2402 | if (!nr_pages) |
| 2403 | return 0; |
| 2404 | |
| 2405 | /* read the nodes onto the stack, retry if done during rebind */ |
| 2406 | do { |
| 2407 | cpuset_mems_cookie = read_mems_allowed_begin(); |
| 2408 | nnodes = read_once_policy_nodemask(pol, &nodes); |
| 2409 | } while (read_mems_allowed_retry(cpuset_mems_cookie)); |
| 2410 | |
| 2411 | /* if the nodemask has become invalid, we cannot do anything */ |
| 2412 | if (!nnodes) |
| 2413 | return 0; |
| 2414 | |
| 2415 | /* Continue allocating from most recent node and adjust the nr_pages */ |
| 2416 | node = me->il_prev; |
| 2417 | weight = me->il_weight; |
| 2418 | if (weight && node_isset(node, nodes)) { |
| 2419 | node_pages = min(rem_pages, weight); |
| 2420 | nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, |
| 2421 | NULL, page_array); |
| 2422 | page_array += nr_allocated; |
| 2423 | total_allocated += nr_allocated; |
| 2424 | /* if that's all the pages, no need to interleave */ |
| 2425 | if (rem_pages <= weight) { |
| 2426 | me->il_weight -= rem_pages; |
| 2427 | return total_allocated; |
| 2428 | } |
| 2429 | /* Otherwise we adjust remaining pages, continue from there */ |
| 2430 | rem_pages -= weight; |
| 2431 | } |
| 2432 | /* clear active weight in case of an allocation failure */ |
| 2433 | me->il_weight = 0; |
| 2434 | prev_node = node; |
| 2435 | |
| 2436 | /* create a local copy of node weights to operate on outside rcu */ |
| 2437 | weights = kzalloc(nr_node_ids, GFP_KERNEL); |
| 2438 | if (!weights) |
| 2439 | return total_allocated; |
| 2440 | |
| 2441 | rcu_read_lock(); |
| 2442 | table = rcu_dereference(iw_table); |
| 2443 | if (table) |
| 2444 | memcpy(weights, table, nr_node_ids); |
| 2445 | rcu_read_unlock(); |
| 2446 | |
| 2447 | /* calculate total, detect system default usage */ |
| 2448 | for_each_node_mask(node, nodes) { |
| 2449 | if (!weights[node]) |
| 2450 | weights[node] = 1; |
| 2451 | weight_total += weights[node]; |
| 2452 | } |
| 2453 | |
| 2454 | /* |
| 2455 | * Calculate rounds/partial rounds to minimize __alloc_pages_bulk calls. |
| 2456 | * Track which node weighted interleave should resume from. |
| 2457 | * |
| 2458 | * if (rounds > 0) and (delta == 0), resume_node will always be |
| 2459 | * the node following prev_node and its weight. |
| 2460 | */ |
| 2461 | rounds = rem_pages / weight_total; |
| 2462 | delta = rem_pages % weight_total; |
| 2463 | resume_node = next_node_in(prev_node, nodes); |
| 2464 | resume_weight = weights[resume_node]; |
| 2465 | for (i = 0; i < nnodes; i++) { |
| 2466 | node = next_node_in(prev_node, nodes); |
| 2467 | weight = weights[node]; |
| 2468 | node_pages = weight * rounds; |
| 2469 | /* If a delta exists, add this node's portion of the delta */ |
| 2470 | if (delta > weight) { |
| 2471 | node_pages += weight; |
| 2472 | delta -= weight; |
| 2473 | } else if (delta) { |
| 2474 | /* when delta is depleted, resume from that node */ |
| 2475 | node_pages += delta; |
| 2476 | resume_node = node; |
| 2477 | resume_weight = weight - delta; |
| 2478 | delta = 0; |
| 2479 | } |
| 2480 | /* node_pages can be 0 if an allocation fails and rounds == 0 */ |
| 2481 | if (!node_pages) |
| 2482 | break; |
| 2483 | nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages, |
| 2484 | NULL, page_array); |
| 2485 | page_array += nr_allocated; |
| 2486 | total_allocated += nr_allocated; |
| 2487 | if (total_allocated == nr_pages) |
| 2488 | break; |
| 2489 | prev_node = node; |
| 2490 | } |
| 2491 | me->il_prev = resume_node; |
| 2492 | me->il_weight = resume_weight; |
| 2493 | kfree(weights); |
| 2494 | return total_allocated; |
| 2495 | } |
| 2496 | |
| 2497 | static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid, |
| 2498 | struct mempolicy *pol, unsigned long nr_pages, |
| 2499 | struct page **page_array) |
| 2500 | { |
| 2501 | gfp_t preferred_gfp; |
| 2502 | unsigned long nr_allocated = 0; |
| 2503 | |
| 2504 | preferred_gfp = gfp | __GFP_NOWARN; |
| 2505 | preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); |
| 2506 | |
| 2507 | nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes, |
| 2508 | nr_pages, NULL, page_array); |
| 2509 | |
| 2510 | if (nr_allocated < nr_pages) |
| 2511 | nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL, |
| 2512 | nr_pages - nr_allocated, NULL, |
| 2513 | page_array + nr_allocated); |
| 2514 | return nr_allocated; |
| 2515 | } |
| 2516 | |
| 2517 | /* alloc pages bulk and mempolicy should be considered at the |
| 2518 | * same time in some situation such as vmalloc. |
| 2519 | * |
| 2520 | * It can accelerate memory allocation especially interleaving |
| 2521 | * allocate memory. |
| 2522 | */ |
| 2523 | unsigned long alloc_pages_bulk_array_mempolicy_noprof(gfp_t gfp, |
| 2524 | unsigned long nr_pages, struct page **page_array) |
| 2525 | { |
| 2526 | struct mempolicy *pol = &default_policy; |
| 2527 | nodemask_t *nodemask; |
| 2528 | int nid; |
| 2529 | |
| 2530 | if (!in_interrupt() && !(gfp & __GFP_THISNODE)) |
| 2531 | pol = get_task_policy(current); |
| 2532 | |
| 2533 | if (pol->mode == MPOL_INTERLEAVE) |
| 2534 | return alloc_pages_bulk_array_interleave(gfp, pol, |
| 2535 | nr_pages, page_array); |
| 2536 | |
| 2537 | if (pol->mode == MPOL_WEIGHTED_INTERLEAVE) |
| 2538 | return alloc_pages_bulk_array_weighted_interleave( |
| 2539 | gfp, pol, nr_pages, page_array); |
| 2540 | |
| 2541 | if (pol->mode == MPOL_PREFERRED_MANY) |
| 2542 | return alloc_pages_bulk_array_preferred_many(gfp, |
| 2543 | numa_node_id(), pol, nr_pages, page_array); |
| 2544 | |
| 2545 | nid = numa_node_id(); |
| 2546 | nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid); |
| 2547 | return alloc_pages_bulk_noprof(gfp, nid, nodemask, |
| 2548 | nr_pages, NULL, page_array); |
| 2549 | } |
| 2550 | |
| 2551 | int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) |
| 2552 | { |
| 2553 | struct mempolicy *pol = mpol_dup(src->vm_policy); |
| 2554 | |
| 2555 | if (IS_ERR(pol)) |
| 2556 | return PTR_ERR(pol); |
| 2557 | dst->vm_policy = pol; |
| 2558 | return 0; |
| 2559 | } |
| 2560 | |
| 2561 | /* |
| 2562 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it |
| 2563 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() |
| 2564 | * with the mems_allowed returned by cpuset_mems_allowed(). This |
| 2565 | * keeps mempolicies cpuset relative after its cpuset moves. See |
| 2566 | * further kernel/cpuset.c update_nodemask(). |
| 2567 | * |
| 2568 | * current's mempolicy may be rebinded by the other task(the task that changes |
| 2569 | * cpuset's mems), so we needn't do rebind work for current task. |
| 2570 | */ |
| 2571 | |
| 2572 | /* Slow path of a mempolicy duplicate */ |
| 2573 | struct mempolicy *__mpol_dup(struct mempolicy *old) |
| 2574 | { |
| 2575 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 2576 | |
| 2577 | if (!new) |
| 2578 | return ERR_PTR(-ENOMEM); |
| 2579 | |
| 2580 | /* task's mempolicy is protected by alloc_lock */ |
| 2581 | if (old == current->mempolicy) { |
| 2582 | task_lock(current); |
| 2583 | *new = *old; |
| 2584 | task_unlock(current); |
| 2585 | } else |
| 2586 | *new = *old; |
| 2587 | |
| 2588 | if (current_cpuset_is_being_rebound()) { |
| 2589 | nodemask_t mems = cpuset_mems_allowed(current); |
| 2590 | mpol_rebind_policy(new, &mems); |
| 2591 | } |
| 2592 | atomic_set(&new->refcnt, 1); |
| 2593 | return new; |
| 2594 | } |
| 2595 | |
| 2596 | /* Slow path of a mempolicy comparison */ |
| 2597 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) |
| 2598 | { |
| 2599 | if (!a || !b) |
| 2600 | return false; |
| 2601 | if (a->mode != b->mode) |
| 2602 | return false; |
| 2603 | if (a->flags != b->flags) |
| 2604 | return false; |
| 2605 | if (a->home_node != b->home_node) |
| 2606 | return false; |
| 2607 | if (mpol_store_user_nodemask(a)) |
| 2608 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) |
| 2609 | return false; |
| 2610 | |
| 2611 | switch (a->mode) { |
| 2612 | case MPOL_BIND: |
| 2613 | case MPOL_INTERLEAVE: |
| 2614 | case MPOL_PREFERRED: |
| 2615 | case MPOL_PREFERRED_MANY: |
| 2616 | case MPOL_WEIGHTED_INTERLEAVE: |
| 2617 | return !!nodes_equal(a->nodes, b->nodes); |
| 2618 | case MPOL_LOCAL: |
| 2619 | return true; |
| 2620 | default: |
| 2621 | BUG(); |
| 2622 | return false; |
| 2623 | } |
| 2624 | } |
| 2625 | |
| 2626 | /* |
| 2627 | * Shared memory backing store policy support. |
| 2628 | * |
| 2629 | * Remember policies even when nobody has shared memory mapped. |
| 2630 | * The policies are kept in Red-Black tree linked from the inode. |
| 2631 | * They are protected by the sp->lock rwlock, which should be held |
| 2632 | * for any accesses to the tree. |
| 2633 | */ |
| 2634 | |
| 2635 | /* |
| 2636 | * lookup first element intersecting start-end. Caller holds sp->lock for |
| 2637 | * reading or for writing |
| 2638 | */ |
| 2639 | static struct sp_node *sp_lookup(struct shared_policy *sp, |
| 2640 | pgoff_t start, pgoff_t end) |
| 2641 | { |
| 2642 | struct rb_node *n = sp->root.rb_node; |
| 2643 | |
| 2644 | while (n) { |
| 2645 | struct sp_node *p = rb_entry(n, struct sp_node, nd); |
| 2646 | |
| 2647 | if (start >= p->end) |
| 2648 | n = n->rb_right; |
| 2649 | else if (end <= p->start) |
| 2650 | n = n->rb_left; |
| 2651 | else |
| 2652 | break; |
| 2653 | } |
| 2654 | if (!n) |
| 2655 | return NULL; |
| 2656 | for (;;) { |
| 2657 | struct sp_node *w = NULL; |
| 2658 | struct rb_node *prev = rb_prev(n); |
| 2659 | if (!prev) |
| 2660 | break; |
| 2661 | w = rb_entry(prev, struct sp_node, nd); |
| 2662 | if (w->end <= start) |
| 2663 | break; |
| 2664 | n = prev; |
| 2665 | } |
| 2666 | return rb_entry(n, struct sp_node, nd); |
| 2667 | } |
| 2668 | |
| 2669 | /* |
| 2670 | * Insert a new shared policy into the list. Caller holds sp->lock for |
| 2671 | * writing. |
| 2672 | */ |
| 2673 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) |
| 2674 | { |
| 2675 | struct rb_node **p = &sp->root.rb_node; |
| 2676 | struct rb_node *parent = NULL; |
| 2677 | struct sp_node *nd; |
| 2678 | |
| 2679 | while (*p) { |
| 2680 | parent = *p; |
| 2681 | nd = rb_entry(parent, struct sp_node, nd); |
| 2682 | if (new->start < nd->start) |
| 2683 | p = &(*p)->rb_left; |
| 2684 | else if (new->end > nd->end) |
| 2685 | p = &(*p)->rb_right; |
| 2686 | else |
| 2687 | BUG(); |
| 2688 | } |
| 2689 | rb_link_node(&new->nd, parent, p); |
| 2690 | rb_insert_color(&new->nd, &sp->root); |
| 2691 | } |
| 2692 | |
| 2693 | /* Find shared policy intersecting idx */ |
| 2694 | struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp, |
| 2695 | pgoff_t idx) |
| 2696 | { |
| 2697 | struct mempolicy *pol = NULL; |
| 2698 | struct sp_node *sn; |
| 2699 | |
| 2700 | if (!sp->root.rb_node) |
| 2701 | return NULL; |
| 2702 | read_lock(&sp->lock); |
| 2703 | sn = sp_lookup(sp, idx, idx+1); |
| 2704 | if (sn) { |
| 2705 | mpol_get(sn->policy); |
| 2706 | pol = sn->policy; |
| 2707 | } |
| 2708 | read_unlock(&sp->lock); |
| 2709 | return pol; |
| 2710 | } |
| 2711 | |
| 2712 | static void sp_free(struct sp_node *n) |
| 2713 | { |
| 2714 | mpol_put(n->policy); |
| 2715 | kmem_cache_free(sn_cache, n); |
| 2716 | } |
| 2717 | |
| 2718 | /** |
| 2719 | * mpol_misplaced - check whether current folio node is valid in policy |
| 2720 | * |
| 2721 | * @folio: folio to be checked |
| 2722 | * @vmf: structure describing the fault |
| 2723 | * @addr: virtual address in @vma for shared policy lookup and interleave policy |
| 2724 | * |
| 2725 | * Lookup current policy node id for vma,addr and "compare to" folio's |
| 2726 | * node id. Policy determination "mimics" alloc_page_vma(). |
| 2727 | * Called from fault path where we know the vma and faulting address. |
| 2728 | * |
| 2729 | * Return: NUMA_NO_NODE if the page is in a node that is valid for this |
| 2730 | * policy, or a suitable node ID to allocate a replacement folio from. |
| 2731 | */ |
| 2732 | int mpol_misplaced(struct folio *folio, struct vm_fault *vmf, |
| 2733 | unsigned long addr) |
| 2734 | { |
| 2735 | struct mempolicy *pol; |
| 2736 | pgoff_t ilx; |
| 2737 | struct zoneref *z; |
| 2738 | int curnid = folio_nid(folio); |
| 2739 | struct vm_area_struct *vma = vmf->vma; |
| 2740 | int thiscpu = raw_smp_processor_id(); |
| 2741 | int thisnid = numa_node_id(); |
| 2742 | int polnid = NUMA_NO_NODE; |
| 2743 | int ret = NUMA_NO_NODE; |
| 2744 | |
| 2745 | /* |
| 2746 | * Make sure ptl is held so that we don't preempt and we |
| 2747 | * have a stable smp processor id |
| 2748 | */ |
| 2749 | lockdep_assert_held(vmf->ptl); |
| 2750 | pol = get_vma_policy(vma, addr, folio_order(folio), &ilx); |
| 2751 | if (!(pol->flags & MPOL_F_MOF)) |
| 2752 | goto out; |
| 2753 | |
| 2754 | switch (pol->mode) { |
| 2755 | case MPOL_INTERLEAVE: |
| 2756 | polnid = interleave_nid(pol, ilx); |
| 2757 | break; |
| 2758 | |
| 2759 | case MPOL_WEIGHTED_INTERLEAVE: |
| 2760 | polnid = weighted_interleave_nid(pol, ilx); |
| 2761 | break; |
| 2762 | |
| 2763 | case MPOL_PREFERRED: |
| 2764 | if (node_isset(curnid, pol->nodes)) |
| 2765 | goto out; |
| 2766 | polnid = first_node(pol->nodes); |
| 2767 | break; |
| 2768 | |
| 2769 | case MPOL_LOCAL: |
| 2770 | polnid = numa_node_id(); |
| 2771 | break; |
| 2772 | |
| 2773 | case MPOL_BIND: |
| 2774 | case MPOL_PREFERRED_MANY: |
| 2775 | /* |
| 2776 | * Even though MPOL_PREFERRED_MANY can allocate pages outside |
| 2777 | * policy nodemask we don't allow numa migration to nodes |
| 2778 | * outside policy nodemask for now. This is done so that if we |
| 2779 | * want demotion to slow memory to happen, before allocating |
| 2780 | * from some DRAM node say 'x', we will end up using a |
| 2781 | * MPOL_PREFERRED_MANY mask excluding node 'x'. In such scenario |
| 2782 | * we should not promote to node 'x' from slow memory node. |
| 2783 | */ |
| 2784 | if (pol->flags & MPOL_F_MORON) { |
| 2785 | /* |
| 2786 | * Optimize placement among multiple nodes |
| 2787 | * via NUMA balancing |
| 2788 | */ |
| 2789 | if (node_isset(thisnid, pol->nodes)) |
| 2790 | break; |
| 2791 | goto out; |
| 2792 | } |
| 2793 | |
| 2794 | /* |
| 2795 | * use current page if in policy nodemask, |
| 2796 | * else select nearest allowed node, if any. |
| 2797 | * If no allowed nodes, use current [!misplaced]. |
| 2798 | */ |
| 2799 | if (node_isset(curnid, pol->nodes)) |
| 2800 | goto out; |
| 2801 | z = first_zones_zonelist( |
| 2802 | node_zonelist(thisnid, GFP_HIGHUSER), |
| 2803 | gfp_zone(GFP_HIGHUSER), |
| 2804 | &pol->nodes); |
| 2805 | polnid = zone_to_nid(z->zone); |
| 2806 | break; |
| 2807 | |
| 2808 | default: |
| 2809 | BUG(); |
| 2810 | } |
| 2811 | |
| 2812 | /* Migrate the folio towards the node whose CPU is referencing it */ |
| 2813 | if (pol->flags & MPOL_F_MORON) { |
| 2814 | polnid = thisnid; |
| 2815 | |
| 2816 | if (!should_numa_migrate_memory(current, folio, curnid, |
| 2817 | thiscpu)) |
| 2818 | goto out; |
| 2819 | } |
| 2820 | |
| 2821 | if (curnid != polnid) |
| 2822 | ret = polnid; |
| 2823 | out: |
| 2824 | mpol_cond_put(pol); |
| 2825 | |
| 2826 | return ret; |
| 2827 | } |
| 2828 | |
| 2829 | /* |
| 2830 | * Drop the (possibly final) reference to task->mempolicy. It needs to be |
| 2831 | * dropped after task->mempolicy is set to NULL so that any allocation done as |
| 2832 | * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed |
| 2833 | * policy. |
| 2834 | */ |
| 2835 | void mpol_put_task_policy(struct task_struct *task) |
| 2836 | { |
| 2837 | struct mempolicy *pol; |
| 2838 | |
| 2839 | task_lock(task); |
| 2840 | pol = task->mempolicy; |
| 2841 | task->mempolicy = NULL; |
| 2842 | task_unlock(task); |
| 2843 | mpol_put(pol); |
| 2844 | } |
| 2845 | |
| 2846 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) |
| 2847 | { |
| 2848 | rb_erase(&n->nd, &sp->root); |
| 2849 | sp_free(n); |
| 2850 | } |
| 2851 | |
| 2852 | static void sp_node_init(struct sp_node *node, unsigned long start, |
| 2853 | unsigned long end, struct mempolicy *pol) |
| 2854 | { |
| 2855 | node->start = start; |
| 2856 | node->end = end; |
| 2857 | node->policy = pol; |
| 2858 | } |
| 2859 | |
| 2860 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, |
| 2861 | struct mempolicy *pol) |
| 2862 | { |
| 2863 | struct sp_node *n; |
| 2864 | struct mempolicy *newpol; |
| 2865 | |
| 2866 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
| 2867 | if (!n) |
| 2868 | return NULL; |
| 2869 | |
| 2870 | newpol = mpol_dup(pol); |
| 2871 | if (IS_ERR(newpol)) { |
| 2872 | kmem_cache_free(sn_cache, n); |
| 2873 | return NULL; |
| 2874 | } |
| 2875 | newpol->flags |= MPOL_F_SHARED; |
| 2876 | sp_node_init(n, start, end, newpol); |
| 2877 | |
| 2878 | return n; |
| 2879 | } |
| 2880 | |
| 2881 | /* Replace a policy range. */ |
| 2882 | static int shared_policy_replace(struct shared_policy *sp, pgoff_t start, |
| 2883 | pgoff_t end, struct sp_node *new) |
| 2884 | { |
| 2885 | struct sp_node *n; |
| 2886 | struct sp_node *n_new = NULL; |
| 2887 | struct mempolicy *mpol_new = NULL; |
| 2888 | int ret = 0; |
| 2889 | |
| 2890 | restart: |
| 2891 | write_lock(&sp->lock); |
| 2892 | n = sp_lookup(sp, start, end); |
| 2893 | /* Take care of old policies in the same range. */ |
| 2894 | while (n && n->start < end) { |
| 2895 | struct rb_node *next = rb_next(&n->nd); |
| 2896 | if (n->start >= start) { |
| 2897 | if (n->end <= end) |
| 2898 | sp_delete(sp, n); |
| 2899 | else |
| 2900 | n->start = end; |
| 2901 | } else { |
| 2902 | /* Old policy spanning whole new range. */ |
| 2903 | if (n->end > end) { |
| 2904 | if (!n_new) |
| 2905 | goto alloc_new; |
| 2906 | |
| 2907 | *mpol_new = *n->policy; |
| 2908 | atomic_set(&mpol_new->refcnt, 1); |
| 2909 | sp_node_init(n_new, end, n->end, mpol_new); |
| 2910 | n->end = start; |
| 2911 | sp_insert(sp, n_new); |
| 2912 | n_new = NULL; |
| 2913 | mpol_new = NULL; |
| 2914 | break; |
| 2915 | } else |
| 2916 | n->end = start; |
| 2917 | } |
| 2918 | if (!next) |
| 2919 | break; |
| 2920 | n = rb_entry(next, struct sp_node, nd); |
| 2921 | } |
| 2922 | if (new) |
| 2923 | sp_insert(sp, new); |
| 2924 | write_unlock(&sp->lock); |
| 2925 | ret = 0; |
| 2926 | |
| 2927 | err_out: |
| 2928 | if (mpol_new) |
| 2929 | mpol_put(mpol_new); |
| 2930 | if (n_new) |
| 2931 | kmem_cache_free(sn_cache, n_new); |
| 2932 | |
| 2933 | return ret; |
| 2934 | |
| 2935 | alloc_new: |
| 2936 | write_unlock(&sp->lock); |
| 2937 | ret = -ENOMEM; |
| 2938 | n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
| 2939 | if (!n_new) |
| 2940 | goto err_out; |
| 2941 | mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
| 2942 | if (!mpol_new) |
| 2943 | goto err_out; |
| 2944 | atomic_set(&mpol_new->refcnt, 1); |
| 2945 | goto restart; |
| 2946 | } |
| 2947 | |
| 2948 | /** |
| 2949 | * mpol_shared_policy_init - initialize shared policy for inode |
| 2950 | * @sp: pointer to inode shared policy |
| 2951 | * @mpol: struct mempolicy to install |
| 2952 | * |
| 2953 | * Install non-NULL @mpol in inode's shared policy rb-tree. |
| 2954 | * On entry, the current task has a reference on a non-NULL @mpol. |
| 2955 | * This must be released on exit. |
| 2956 | * This is called at get_inode() calls and we can use GFP_KERNEL. |
| 2957 | */ |
| 2958 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) |
| 2959 | { |
| 2960 | int ret; |
| 2961 | |
| 2962 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ |
| 2963 | rwlock_init(&sp->lock); |
| 2964 | |
| 2965 | if (mpol) { |
| 2966 | struct sp_node *sn; |
| 2967 | struct mempolicy *npol; |
| 2968 | NODEMASK_SCRATCH(scratch); |
| 2969 | |
| 2970 | if (!scratch) |
| 2971 | goto put_mpol; |
| 2972 | |
| 2973 | /* contextualize the tmpfs mount point mempolicy to this file */ |
| 2974 | npol = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); |
| 2975 | if (IS_ERR(npol)) |
| 2976 | goto free_scratch; /* no valid nodemask intersection */ |
| 2977 | |
| 2978 | task_lock(current); |
| 2979 | ret = mpol_set_nodemask(npol, &mpol->w.user_nodemask, scratch); |
| 2980 | task_unlock(current); |
| 2981 | if (ret) |
| 2982 | goto put_npol; |
| 2983 | |
| 2984 | /* alloc node covering entire file; adds ref to file's npol */ |
| 2985 | sn = sp_alloc(0, MAX_LFS_FILESIZE >> PAGE_SHIFT, npol); |
| 2986 | if (sn) |
| 2987 | sp_insert(sp, sn); |
| 2988 | put_npol: |
| 2989 | mpol_put(npol); /* drop initial ref on file's npol */ |
| 2990 | free_scratch: |
| 2991 | NODEMASK_SCRATCH_FREE(scratch); |
| 2992 | put_mpol: |
| 2993 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ |
| 2994 | } |
| 2995 | } |
| 2996 | |
| 2997 | int mpol_set_shared_policy(struct shared_policy *sp, |
| 2998 | struct vm_area_struct *vma, struct mempolicy *pol) |
| 2999 | { |
| 3000 | int err; |
| 3001 | struct sp_node *new = NULL; |
| 3002 | unsigned long sz = vma_pages(vma); |
| 3003 | |
| 3004 | if (pol) { |
| 3005 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, pol); |
| 3006 | if (!new) |
| 3007 | return -ENOMEM; |
| 3008 | } |
| 3009 | err = shared_policy_replace(sp, vma->vm_pgoff, vma->vm_pgoff + sz, new); |
| 3010 | if (err && new) |
| 3011 | sp_free(new); |
| 3012 | return err; |
| 3013 | } |
| 3014 | |
| 3015 | /* Free a backing policy store on inode delete. */ |
| 3016 | void mpol_free_shared_policy(struct shared_policy *sp) |
| 3017 | { |
| 3018 | struct sp_node *n; |
| 3019 | struct rb_node *next; |
| 3020 | |
| 3021 | if (!sp->root.rb_node) |
| 3022 | return; |
| 3023 | write_lock(&sp->lock); |
| 3024 | next = rb_first(&sp->root); |
| 3025 | while (next) { |
| 3026 | n = rb_entry(next, struct sp_node, nd); |
| 3027 | next = rb_next(&n->nd); |
| 3028 | sp_delete(sp, n); |
| 3029 | } |
| 3030 | write_unlock(&sp->lock); |
| 3031 | } |
| 3032 | |
| 3033 | #ifdef CONFIG_NUMA_BALANCING |
| 3034 | static int __initdata numabalancing_override; |
| 3035 | |
| 3036 | static void __init check_numabalancing_enable(void) |
| 3037 | { |
| 3038 | bool numabalancing_default = false; |
| 3039 | |
| 3040 | if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED)) |
| 3041 | numabalancing_default = true; |
| 3042 | |
| 3043 | /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */ |
| 3044 | if (numabalancing_override) |
| 3045 | set_numabalancing_state(numabalancing_override == 1); |
| 3046 | |
| 3047 | if (num_online_nodes() > 1 && !numabalancing_override) { |
| 3048 | pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n", |
| 3049 | numabalancing_default ? "Enabling" : "Disabling"); |
| 3050 | set_numabalancing_state(numabalancing_default); |
| 3051 | } |
| 3052 | } |
| 3053 | |
| 3054 | static int __init setup_numabalancing(char *str) |
| 3055 | { |
| 3056 | int ret = 0; |
| 3057 | if (!str) |
| 3058 | goto out; |
| 3059 | |
| 3060 | if (!strcmp(str, "enable")) { |
| 3061 | numabalancing_override = 1; |
| 3062 | ret = 1; |
| 3063 | } else if (!strcmp(str, "disable")) { |
| 3064 | numabalancing_override = -1; |
| 3065 | ret = 1; |
| 3066 | } |
| 3067 | out: |
| 3068 | if (!ret) |
| 3069 | pr_warn("Unable to parse numa_balancing=\n"); |
| 3070 | |
| 3071 | return ret; |
| 3072 | } |
| 3073 | __setup("numa_balancing=", setup_numabalancing); |
| 3074 | #else |
| 3075 | static inline void __init check_numabalancing_enable(void) |
| 3076 | { |
| 3077 | } |
| 3078 | #endif /* CONFIG_NUMA_BALANCING */ |
| 3079 | |
| 3080 | void __init numa_policy_init(void) |
| 3081 | { |
| 3082 | nodemask_t interleave_nodes; |
| 3083 | unsigned long largest = 0; |
| 3084 | int nid, prefer = 0; |
| 3085 | |
| 3086 | policy_cache = kmem_cache_create("numa_policy", |
| 3087 | sizeof(struct mempolicy), |
| 3088 | 0, SLAB_PANIC, NULL); |
| 3089 | |
| 3090 | sn_cache = kmem_cache_create("shared_policy_node", |
| 3091 | sizeof(struct sp_node), |
| 3092 | 0, SLAB_PANIC, NULL); |
| 3093 | |
| 3094 | for_each_node(nid) { |
| 3095 | preferred_node_policy[nid] = (struct mempolicy) { |
| 3096 | .refcnt = ATOMIC_INIT(1), |
| 3097 | .mode = MPOL_PREFERRED, |
| 3098 | .flags = MPOL_F_MOF | MPOL_F_MORON, |
| 3099 | .nodes = nodemask_of_node(nid), |
| 3100 | }; |
| 3101 | } |
| 3102 | |
| 3103 | /* |
| 3104 | * Set interleaving policy for system init. Interleaving is only |
| 3105 | * enabled across suitably sized nodes (default is >= 16MB), or |
| 3106 | * fall back to the largest node if they're all smaller. |
| 3107 | */ |
| 3108 | nodes_clear(interleave_nodes); |
| 3109 | for_each_node_state(nid, N_MEMORY) { |
| 3110 | unsigned long total_pages = node_present_pages(nid); |
| 3111 | |
| 3112 | /* Preserve the largest node */ |
| 3113 | if (largest < total_pages) { |
| 3114 | largest = total_pages; |
| 3115 | prefer = nid; |
| 3116 | } |
| 3117 | |
| 3118 | /* Interleave this node? */ |
| 3119 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) |
| 3120 | node_set(nid, interleave_nodes); |
| 3121 | } |
| 3122 | |
| 3123 | /* All too small, use the largest */ |
| 3124 | if (unlikely(nodes_empty(interleave_nodes))) |
| 3125 | node_set(prefer, interleave_nodes); |
| 3126 | |
| 3127 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) |
| 3128 | pr_err("%s: interleaving failed\n", __func__); |
| 3129 | |
| 3130 | check_numabalancing_enable(); |
| 3131 | } |
| 3132 | |
| 3133 | /* Reset policy of current process to default */ |
| 3134 | void numa_default_policy(void) |
| 3135 | { |
| 3136 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); |
| 3137 | } |
| 3138 | |
| 3139 | /* |
| 3140 | * Parse and format mempolicy from/to strings |
| 3141 | */ |
| 3142 | static const char * const policy_modes[] = |
| 3143 | { |
| 3144 | [MPOL_DEFAULT] = "default", |
| 3145 | [MPOL_PREFERRED] = "prefer", |
| 3146 | [MPOL_BIND] = "bind", |
| 3147 | [MPOL_INTERLEAVE] = "interleave", |
| 3148 | [MPOL_WEIGHTED_INTERLEAVE] = "weighted interleave", |
| 3149 | [MPOL_LOCAL] = "local", |
| 3150 | [MPOL_PREFERRED_MANY] = "prefer (many)", |
| 3151 | }; |
| 3152 | |
| 3153 | #ifdef CONFIG_TMPFS |
| 3154 | /** |
| 3155 | * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option. |
| 3156 | * @str: string containing mempolicy to parse |
| 3157 | * @mpol: pointer to struct mempolicy pointer, returned on success. |
| 3158 | * |
| 3159 | * Format of input: |
| 3160 | * <mode>[=<flags>][:<nodelist>] |
| 3161 | * |
| 3162 | * Return: %0 on success, else %1 |
| 3163 | */ |
| 3164 | int mpol_parse_str(char *str, struct mempolicy **mpol) |
| 3165 | { |
| 3166 | struct mempolicy *new = NULL; |
| 3167 | unsigned short mode_flags; |
| 3168 | nodemask_t nodes; |
| 3169 | char *nodelist = strchr(str, ':'); |
| 3170 | char *flags = strchr(str, '='); |
| 3171 | int err = 1, mode; |
| 3172 | |
| 3173 | if (flags) |
| 3174 | *flags++ = '\0'; /* terminate mode string */ |
| 3175 | |
| 3176 | if (nodelist) { |
| 3177 | /* NUL-terminate mode or flags string */ |
| 3178 | *nodelist++ = '\0'; |
| 3179 | if (nodelist_parse(nodelist, nodes)) |
| 3180 | goto out; |
| 3181 | if (!nodes_subset(nodes, node_states[N_MEMORY])) |
| 3182 | goto out; |
| 3183 | } else |
| 3184 | nodes_clear(nodes); |
| 3185 | |
| 3186 | mode = match_string(policy_modes, MPOL_MAX, str); |
| 3187 | if (mode < 0) |
| 3188 | goto out; |
| 3189 | |
| 3190 | switch (mode) { |
| 3191 | case MPOL_PREFERRED: |
| 3192 | /* |
| 3193 | * Insist on a nodelist of one node only, although later |
| 3194 | * we use first_node(nodes) to grab a single node, so here |
| 3195 | * nodelist (or nodes) cannot be empty. |
| 3196 | */ |
| 3197 | if (nodelist) { |
| 3198 | char *rest = nodelist; |
| 3199 | while (isdigit(*rest)) |
| 3200 | rest++; |
| 3201 | if (*rest) |
| 3202 | goto out; |
| 3203 | if (nodes_empty(nodes)) |
| 3204 | goto out; |
| 3205 | } |
| 3206 | break; |
| 3207 | case MPOL_INTERLEAVE: |
| 3208 | case MPOL_WEIGHTED_INTERLEAVE: |
| 3209 | /* |
| 3210 | * Default to online nodes with memory if no nodelist |
| 3211 | */ |
| 3212 | if (!nodelist) |
| 3213 | nodes = node_states[N_MEMORY]; |
| 3214 | break; |
| 3215 | case MPOL_LOCAL: |
| 3216 | /* |
| 3217 | * Don't allow a nodelist; mpol_new() checks flags |
| 3218 | */ |
| 3219 | if (nodelist) |
| 3220 | goto out; |
| 3221 | break; |
| 3222 | case MPOL_DEFAULT: |
| 3223 | /* |
| 3224 | * Insist on a empty nodelist |
| 3225 | */ |
| 3226 | if (!nodelist) |
| 3227 | err = 0; |
| 3228 | goto out; |
| 3229 | case MPOL_PREFERRED_MANY: |
| 3230 | case MPOL_BIND: |
| 3231 | /* |
| 3232 | * Insist on a nodelist |
| 3233 | */ |
| 3234 | if (!nodelist) |
| 3235 | goto out; |
| 3236 | } |
| 3237 | |
| 3238 | mode_flags = 0; |
| 3239 | if (flags) { |
| 3240 | /* |
| 3241 | * Currently, we only support two mutually exclusive |
| 3242 | * mode flags. |
| 3243 | */ |
| 3244 | if (!strcmp(flags, "static")) |
| 3245 | mode_flags |= MPOL_F_STATIC_NODES; |
| 3246 | else if (!strcmp(flags, "relative")) |
| 3247 | mode_flags |= MPOL_F_RELATIVE_NODES; |
| 3248 | else |
| 3249 | goto out; |
| 3250 | } |
| 3251 | |
| 3252 | new = mpol_new(mode, mode_flags, &nodes); |
| 3253 | if (IS_ERR(new)) |
| 3254 | goto out; |
| 3255 | |
| 3256 | /* |
| 3257 | * Save nodes for mpol_to_str() to show the tmpfs mount options |
| 3258 | * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo. |
| 3259 | */ |
| 3260 | if (mode != MPOL_PREFERRED) { |
| 3261 | new->nodes = nodes; |
| 3262 | } else if (nodelist) { |
| 3263 | nodes_clear(new->nodes); |
| 3264 | node_set(first_node(nodes), new->nodes); |
| 3265 | } else { |
| 3266 | new->mode = MPOL_LOCAL; |
| 3267 | } |
| 3268 | |
| 3269 | /* |
| 3270 | * Save nodes for contextualization: this will be used to "clone" |
| 3271 | * the mempolicy in a specific context [cpuset] at a later time. |
| 3272 | */ |
| 3273 | new->w.user_nodemask = nodes; |
| 3274 | |
| 3275 | err = 0; |
| 3276 | |
| 3277 | out: |
| 3278 | /* Restore string for error message */ |
| 3279 | if (nodelist) |
| 3280 | *--nodelist = ':'; |
| 3281 | if (flags) |
| 3282 | *--flags = '='; |
| 3283 | if (!err) |
| 3284 | *mpol = new; |
| 3285 | return err; |
| 3286 | } |
| 3287 | #endif /* CONFIG_TMPFS */ |
| 3288 | |
| 3289 | /** |
| 3290 | * mpol_to_str - format a mempolicy structure for printing |
| 3291 | * @buffer: to contain formatted mempolicy string |
| 3292 | * @maxlen: length of @buffer |
| 3293 | * @pol: pointer to mempolicy to be formatted |
| 3294 | * |
| 3295 | * Convert @pol into a string. If @buffer is too short, truncate the string. |
| 3296 | * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the |
| 3297 | * longest flag, "relative", and to display at least a few node ids. |
| 3298 | */ |
| 3299 | void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) |
| 3300 | { |
| 3301 | char *p = buffer; |
| 3302 | nodemask_t nodes = NODE_MASK_NONE; |
| 3303 | unsigned short mode = MPOL_DEFAULT; |
| 3304 | unsigned short flags = 0; |
| 3305 | |
| 3306 | if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) { |
| 3307 | mode = pol->mode; |
| 3308 | flags = pol->flags; |
| 3309 | } |
| 3310 | |
| 3311 | switch (mode) { |
| 3312 | case MPOL_DEFAULT: |
| 3313 | case MPOL_LOCAL: |
| 3314 | break; |
| 3315 | case MPOL_PREFERRED: |
| 3316 | case MPOL_PREFERRED_MANY: |
| 3317 | case MPOL_BIND: |
| 3318 | case MPOL_INTERLEAVE: |
| 3319 | case MPOL_WEIGHTED_INTERLEAVE: |
| 3320 | nodes = pol->nodes; |
| 3321 | break; |
| 3322 | default: |
| 3323 | WARN_ON_ONCE(1); |
| 3324 | snprintf(p, maxlen, "unknown"); |
| 3325 | return; |
| 3326 | } |
| 3327 | |
| 3328 | p += snprintf(p, maxlen, "%s", policy_modes[mode]); |
| 3329 | |
| 3330 | if (flags & MPOL_MODE_FLAGS) { |
| 3331 | p += snprintf(p, buffer + maxlen - p, "="); |
| 3332 | |
| 3333 | /* |
| 3334 | * Currently, the only defined flags are mutually exclusive |
| 3335 | */ |
| 3336 | if (flags & MPOL_F_STATIC_NODES) |
| 3337 | p += snprintf(p, buffer + maxlen - p, "static"); |
| 3338 | else if (flags & MPOL_F_RELATIVE_NODES) |
| 3339 | p += snprintf(p, buffer + maxlen - p, "relative"); |
| 3340 | } |
| 3341 | |
| 3342 | if (!nodes_empty(nodes)) |
| 3343 | p += scnprintf(p, buffer + maxlen - p, ":%*pbl", |
| 3344 | nodemask_pr_args(&nodes)); |
| 3345 | } |
| 3346 | |
| 3347 | #ifdef CONFIG_SYSFS |
| 3348 | struct iw_node_attr { |
| 3349 | struct kobj_attribute kobj_attr; |
| 3350 | int nid; |
| 3351 | }; |
| 3352 | |
| 3353 | static ssize_t node_show(struct kobject *kobj, struct kobj_attribute *attr, |
| 3354 | char *buf) |
| 3355 | { |
| 3356 | struct iw_node_attr *node_attr; |
| 3357 | u8 weight; |
| 3358 | |
| 3359 | node_attr = container_of(attr, struct iw_node_attr, kobj_attr); |
| 3360 | weight = get_il_weight(node_attr->nid); |
| 3361 | return sysfs_emit(buf, "%d\n", weight); |
| 3362 | } |
| 3363 | |
| 3364 | static ssize_t node_store(struct kobject *kobj, struct kobj_attribute *attr, |
| 3365 | const char *buf, size_t count) |
| 3366 | { |
| 3367 | struct iw_node_attr *node_attr; |
| 3368 | u8 *new; |
| 3369 | u8 *old; |
| 3370 | u8 weight = 0; |
| 3371 | |
| 3372 | node_attr = container_of(attr, struct iw_node_attr, kobj_attr); |
| 3373 | if (count == 0 || sysfs_streq(buf, "")) |
| 3374 | weight = 0; |
| 3375 | else if (kstrtou8(buf, 0, &weight)) |
| 3376 | return -EINVAL; |
| 3377 | |
| 3378 | new = kzalloc(nr_node_ids, GFP_KERNEL); |
| 3379 | if (!new) |
| 3380 | return -ENOMEM; |
| 3381 | |
| 3382 | mutex_lock(&iw_table_lock); |
| 3383 | old = rcu_dereference_protected(iw_table, |
| 3384 | lockdep_is_held(&iw_table_lock)); |
| 3385 | if (old) |
| 3386 | memcpy(new, old, nr_node_ids); |
| 3387 | new[node_attr->nid] = weight; |
| 3388 | rcu_assign_pointer(iw_table, new); |
| 3389 | mutex_unlock(&iw_table_lock); |
| 3390 | synchronize_rcu(); |
| 3391 | kfree(old); |
| 3392 | return count; |
| 3393 | } |
| 3394 | |
| 3395 | static struct iw_node_attr **node_attrs; |
| 3396 | |
| 3397 | static void sysfs_wi_node_release(struct iw_node_attr *node_attr, |
| 3398 | struct kobject *parent) |
| 3399 | { |
| 3400 | if (!node_attr) |
| 3401 | return; |
| 3402 | sysfs_remove_file(parent, &node_attr->kobj_attr.attr); |
| 3403 | kfree(node_attr->kobj_attr.attr.name); |
| 3404 | kfree(node_attr); |
| 3405 | } |
| 3406 | |
| 3407 | static void sysfs_wi_release(struct kobject *wi_kobj) |
| 3408 | { |
| 3409 | int i; |
| 3410 | |
| 3411 | for (i = 0; i < nr_node_ids; i++) |
| 3412 | sysfs_wi_node_release(node_attrs[i], wi_kobj); |
| 3413 | kobject_put(wi_kobj); |
| 3414 | } |
| 3415 | |
| 3416 | static const struct kobj_type wi_ktype = { |
| 3417 | .sysfs_ops = &kobj_sysfs_ops, |
| 3418 | .release = sysfs_wi_release, |
| 3419 | }; |
| 3420 | |
| 3421 | static int add_weight_node(int nid, struct kobject *wi_kobj) |
| 3422 | { |
| 3423 | struct iw_node_attr *node_attr; |
| 3424 | char *name; |
| 3425 | |
| 3426 | node_attr = kzalloc(sizeof(*node_attr), GFP_KERNEL); |
| 3427 | if (!node_attr) |
| 3428 | return -ENOMEM; |
| 3429 | |
| 3430 | name = kasprintf(GFP_KERNEL, "node%d", nid); |
| 3431 | if (!name) { |
| 3432 | kfree(node_attr); |
| 3433 | return -ENOMEM; |
| 3434 | } |
| 3435 | |
| 3436 | sysfs_attr_init(&node_attr->kobj_attr.attr); |
| 3437 | node_attr->kobj_attr.attr.name = name; |
| 3438 | node_attr->kobj_attr.attr.mode = 0644; |
| 3439 | node_attr->kobj_attr.show = node_show; |
| 3440 | node_attr->kobj_attr.store = node_store; |
| 3441 | node_attr->nid = nid; |
| 3442 | |
| 3443 | if (sysfs_create_file(wi_kobj, &node_attr->kobj_attr.attr)) { |
| 3444 | kfree(node_attr->kobj_attr.attr.name); |
| 3445 | kfree(node_attr); |
| 3446 | pr_err("failed to add attribute to weighted_interleave\n"); |
| 3447 | return -ENOMEM; |
| 3448 | } |
| 3449 | |
| 3450 | node_attrs[nid] = node_attr; |
| 3451 | return 0; |
| 3452 | } |
| 3453 | |
| 3454 | static int add_weighted_interleave_group(struct kobject *root_kobj) |
| 3455 | { |
| 3456 | struct kobject *wi_kobj; |
| 3457 | int nid, err; |
| 3458 | |
| 3459 | wi_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL); |
| 3460 | if (!wi_kobj) |
| 3461 | return -ENOMEM; |
| 3462 | |
| 3463 | err = kobject_init_and_add(wi_kobj, &wi_ktype, root_kobj, |
| 3464 | "weighted_interleave"); |
| 3465 | if (err) { |
| 3466 | kfree(wi_kobj); |
| 3467 | return err; |
| 3468 | } |
| 3469 | |
| 3470 | for_each_node_state(nid, N_POSSIBLE) { |
| 3471 | err = add_weight_node(nid, wi_kobj); |
| 3472 | if (err) { |
| 3473 | pr_err("failed to add sysfs [node%d]\n", nid); |
| 3474 | break; |
| 3475 | } |
| 3476 | } |
| 3477 | if (err) |
| 3478 | kobject_put(wi_kobj); |
| 3479 | return 0; |
| 3480 | } |
| 3481 | |
| 3482 | static void mempolicy_kobj_release(struct kobject *kobj) |
| 3483 | { |
| 3484 | u8 *old; |
| 3485 | |
| 3486 | mutex_lock(&iw_table_lock); |
| 3487 | old = rcu_dereference_protected(iw_table, |
| 3488 | lockdep_is_held(&iw_table_lock)); |
| 3489 | rcu_assign_pointer(iw_table, NULL); |
| 3490 | mutex_unlock(&iw_table_lock); |
| 3491 | synchronize_rcu(); |
| 3492 | kfree(old); |
| 3493 | kfree(node_attrs); |
| 3494 | kfree(kobj); |
| 3495 | } |
| 3496 | |
| 3497 | static const struct kobj_type mempolicy_ktype = { |
| 3498 | .release = mempolicy_kobj_release |
| 3499 | }; |
| 3500 | |
| 3501 | static int __init mempolicy_sysfs_init(void) |
| 3502 | { |
| 3503 | int err; |
| 3504 | static struct kobject *mempolicy_kobj; |
| 3505 | |
| 3506 | mempolicy_kobj = kzalloc(sizeof(*mempolicy_kobj), GFP_KERNEL); |
| 3507 | if (!mempolicy_kobj) { |
| 3508 | err = -ENOMEM; |
| 3509 | goto err_out; |
| 3510 | } |
| 3511 | |
| 3512 | node_attrs = kcalloc(nr_node_ids, sizeof(struct iw_node_attr *), |
| 3513 | GFP_KERNEL); |
| 3514 | if (!node_attrs) { |
| 3515 | err = -ENOMEM; |
| 3516 | goto mempol_out; |
| 3517 | } |
| 3518 | |
| 3519 | err = kobject_init_and_add(mempolicy_kobj, &mempolicy_ktype, mm_kobj, |
| 3520 | "mempolicy"); |
| 3521 | if (err) |
| 3522 | goto node_out; |
| 3523 | |
| 3524 | err = add_weighted_interleave_group(mempolicy_kobj); |
| 3525 | if (err) { |
| 3526 | pr_err("mempolicy sysfs structure failed to initialize\n"); |
| 3527 | kobject_put(mempolicy_kobj); |
| 3528 | return err; |
| 3529 | } |
| 3530 | |
| 3531 | return err; |
| 3532 | node_out: |
| 3533 | kfree(node_attrs); |
| 3534 | mempol_out: |
| 3535 | kfree(mempolicy_kobj); |
| 3536 | err_out: |
| 3537 | pr_err("failed to add mempolicy kobject to the system\n"); |
| 3538 | return err; |
| 3539 | } |
| 3540 | |
| 3541 | late_initcall(mempolicy_sysfs_init); |
| 3542 | #endif /* CONFIG_SYSFS */ |