1 /* 2 * Simple NUMA memory policy for the Linux kernel. 3 * 4 * Copyright 2003,2004 Andi Kleen, SuSE Labs. 5 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc. 6 * Subject to the GNU Public License, version 2. 7 * 8 * NUMA policy allows the user to give hints in which node(s) memory should 9 * be allocated. 10 * 11 * Support four policies per VMA and per process: 12 * 13 * The VMA policy has priority over the process policy for a page fault. 14 * 15 * interleave Allocate memory interleaved over a set of nodes, 16 * with normal fallback if it fails. 17 * For VMA based allocations this interleaves based on the 18 * offset into the backing object or offset into the mapping 19 * for anonymous memory. For process policy an process counter 20 * is used. 21 * 22 * bind Only allocate memory on a specific set of nodes, 23 * no fallback. 24 * FIXME: memory is allocated starting with the first node 25 * to the last. It would be better if bind would truly restrict 26 * the allocation to memory nodes instead 27 * 28 * preferred Try a specific node first before normal fallback. 29 * As a special case node -1 here means do the allocation 30 * on the local CPU. This is normally identical to default, 31 * but useful to set in a VMA when you have a non default 32 * process policy. 33 * 34 * default Allocate on the local node first, or when on a VMA 35 * use the process policy. This is what Linux always did 36 * in a NUMA aware kernel and still does by, ahem, default. 37 * 38 * The process policy is applied for most non interrupt memory allocations 39 * in that process' context. Interrupts ignore the policies and always 40 * try to allocate on the local CPU. The VMA policy is only applied for memory 41 * allocations for a VMA in the VM. 42 * 43 * Currently there are a few corner cases in swapping where the policy 44 * is not applied, but the majority should be handled. When process policy 45 * is used it is not remembered over swap outs/swap ins. 46 * 47 * Only the highest zone in the zone hierarchy gets policied. Allocations 48 * requesting a lower zone just use default policy. This implies that 49 * on systems with highmem kernel lowmem allocation don't get policied. 50 * Same with GFP_DMA allocations. 51 * 52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between 53 * all users and remembered even when nobody has memory mapped. 54 */ 55 56 /* Notebook: 57 fix mmap readahead to honour policy and enable policy for any page cache 58 object 59 statistics for bigpages 60 global policy for page cache? currently it uses process policy. Requires 61 first item above. 62 handle mremap for shared memory (currently ignored for the policy) 63 grows down? 64 make bind policy root only? It can trigger oom much faster and the 65 kernel is not always grateful with that. 66 */ 67 68 #include <linux/mempolicy.h> 69 #include <linux/mm.h> 70 #include <linux/highmem.h> 71 #include <linux/hugetlb.h> 72 #include <linux/kernel.h> 73 #include <linux/sched.h> 74 #include <linux/nodemask.h> 75 #include <linux/cpuset.h> 76 #include <linux/gfp.h> 77 #include <linux/slab.h> 78 #include <linux/string.h> 79 #include <linux/module.h> 80 #include <linux/nsproxy.h> 81 #include <linux/interrupt.h> 82 #include <linux/init.h> 83 #include <linux/compat.h> 84 #include <linux/swap.h> 85 #include <linux/seq_file.h> 86 #include <linux/proc_fs.h> 87 #include <linux/migrate.h> 88 #include <linux/rmap.h> 89 #include <linux/security.h> 90 #include <linux/syscalls.h> 91 #include <linux/ctype.h> 92 93 #include <asm/tlbflush.h> 94 #include <asm/uaccess.h> 95 96 #include "internal.h" 97 98 /* Internal flags */ 99 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ 100 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ 101 #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */ 102 103 static struct kmem_cache *policy_cache; 104 static struct kmem_cache *sn_cache; 105 106 /* Highest zone. An specific allocation for a zone below that is not 107 policied. */ 108 enum zone_type policy_zone = 0; 109 110 /* 111 * run-time system-wide default policy => local allocation 112 */ 113 struct mempolicy default_policy = { 114 .refcnt = ATOMIC_INIT(1), /* never free it */ 115 .mode = MPOL_PREFERRED, 116 .flags = MPOL_F_LOCAL, 117 }; 118 119 static const struct mempolicy_operations { 120 int (*create)(struct mempolicy *pol, const nodemask_t *nodes); 121 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); 122 } mpol_ops[MPOL_MAX]; 123 124 /* Check that the nodemask contains at least one populated zone */ 125 static int is_valid_nodemask(const nodemask_t *nodemask) 126 { 127 int nd, k; 128 129 /* Check that there is something useful in this mask */ 130 k = policy_zone; 131 132 for_each_node_mask(nd, *nodemask) { 133 struct zone *z; 134 135 for (k = 0; k <= policy_zone; k++) { 136 z = &NODE_DATA(nd)->node_zones[k]; 137 if (z->present_pages > 0) 138 return 1; 139 } 140 } 141 142 return 0; 143 } 144 145 static inline int mpol_store_user_nodemask(const struct mempolicy *pol) 146 { 147 return pol->flags & (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES); 148 } 149 150 static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, 151 const nodemask_t *rel) 152 { 153 nodemask_t tmp; 154 nodes_fold(tmp, *orig, nodes_weight(*rel)); 155 nodes_onto(*ret, tmp, *rel); 156 } 157 158 static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) 159 { 160 if (nodes_empty(*nodes)) 161 return -EINVAL; 162 pol->v.nodes = *nodes; 163 return 0; 164 } 165 166 static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) 167 { 168 if (!nodes) 169 pol->flags |= MPOL_F_LOCAL; /* local allocation */ 170 else if (nodes_empty(*nodes)) 171 return -EINVAL; /* no allowed nodes */ 172 else 173 pol->v.preferred_node = first_node(*nodes); 174 return 0; 175 } 176 177 static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) 178 { 179 if (!is_valid_nodemask(nodes)) 180 return -EINVAL; 181 pol->v.nodes = *nodes; 182 return 0; 183 } 184 185 /* Create a new policy */ 186 static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, 187 nodemask_t *nodes) 188 { 189 struct mempolicy *policy; 190 nodemask_t cpuset_context_nmask; 191 int ret; 192 193 pr_debug("setting mode %d flags %d nodes[0] %lx\n", 194 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1); 195 196 if (mode == MPOL_DEFAULT) { 197 if (nodes && !nodes_empty(*nodes)) 198 return ERR_PTR(-EINVAL); 199 return NULL; /* simply delete any existing policy */ 200 } 201 VM_BUG_ON(!nodes); 202 203 /* 204 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or 205 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). 206 * All other modes require a valid pointer to a non-empty nodemask. 207 */ 208 if (mode == MPOL_PREFERRED) { 209 if (nodes_empty(*nodes)) { 210 if (((flags & MPOL_F_STATIC_NODES) || 211 (flags & MPOL_F_RELATIVE_NODES))) 212 return ERR_PTR(-EINVAL); 213 nodes = NULL; /* flag local alloc */ 214 } 215 } else if (nodes_empty(*nodes)) 216 return ERR_PTR(-EINVAL); 217 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); 218 if (!policy) 219 return ERR_PTR(-ENOMEM); 220 atomic_set(&policy->refcnt, 1); 221 policy->mode = mode; 222 policy->flags = flags; 223 224 if (nodes) { 225 /* 226 * cpuset related setup doesn't apply to local allocation 227 */ 228 cpuset_update_task_memory_state(); 229 if (flags & MPOL_F_RELATIVE_NODES) 230 mpol_relative_nodemask(&cpuset_context_nmask, nodes, 231 &cpuset_current_mems_allowed); 232 else 233 nodes_and(cpuset_context_nmask, *nodes, 234 cpuset_current_mems_allowed); 235 if (mpol_store_user_nodemask(policy)) 236 policy->w.user_nodemask = *nodes; 237 else 238 policy->w.cpuset_mems_allowed = 239 cpuset_mems_allowed(current); 240 } 241 242 ret = mpol_ops[mode].create(policy, 243 nodes ? &cpuset_context_nmask : NULL); 244 if (ret < 0) { 245 kmem_cache_free(policy_cache, policy); 246 return ERR_PTR(ret); 247 } 248 return policy; 249 } 250 251 /* Slow path of a mpol destructor. */ 252 void __mpol_put(struct mempolicy *p) 253 { 254 if (!atomic_dec_and_test(&p->refcnt)) 255 return; 256 kmem_cache_free(policy_cache, p); 257 } 258 259 static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) 260 { 261 } 262 263 static void mpol_rebind_nodemask(struct mempolicy *pol, 264 const nodemask_t *nodes) 265 { 266 nodemask_t tmp; 267 268 if (pol->flags & MPOL_F_STATIC_NODES) 269 nodes_and(tmp, pol->w.user_nodemask, *nodes); 270 else if (pol->flags & MPOL_F_RELATIVE_NODES) 271 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); 272 else { 273 nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed, 274 *nodes); 275 pol->w.cpuset_mems_allowed = *nodes; 276 } 277 278 pol->v.nodes = tmp; 279 if (!node_isset(current->il_next, tmp)) { 280 current->il_next = next_node(current->il_next, tmp); 281 if (current->il_next >= MAX_NUMNODES) 282 current->il_next = first_node(tmp); 283 if (current->il_next >= MAX_NUMNODES) 284 current->il_next = numa_node_id(); 285 } 286 } 287 288 static void mpol_rebind_preferred(struct mempolicy *pol, 289 const nodemask_t *nodes) 290 { 291 nodemask_t tmp; 292 293 if (pol->flags & MPOL_F_STATIC_NODES) { 294 int node = first_node(pol->w.user_nodemask); 295 296 if (node_isset(node, *nodes)) { 297 pol->v.preferred_node = node; 298 pol->flags &= ~MPOL_F_LOCAL; 299 } else 300 pol->flags |= MPOL_F_LOCAL; 301 } else if (pol->flags & MPOL_F_RELATIVE_NODES) { 302 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); 303 pol->v.preferred_node = first_node(tmp); 304 } else if (!(pol->flags & MPOL_F_LOCAL)) { 305 pol->v.preferred_node = node_remap(pol->v.preferred_node, 306 pol->w.cpuset_mems_allowed, 307 *nodes); 308 pol->w.cpuset_mems_allowed = *nodes; 309 } 310 } 311 312 /* Migrate a policy to a different set of nodes */ 313 static void mpol_rebind_policy(struct mempolicy *pol, 314 const nodemask_t *newmask) 315 { 316 if (!pol) 317 return; 318 if (!mpol_store_user_nodemask(pol) && 319 nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) 320 return; 321 mpol_ops[pol->mode].rebind(pol, newmask); 322 } 323 324 /* 325 * Wrapper for mpol_rebind_policy() that just requires task 326 * pointer, and updates task mempolicy. 327 */ 328 329 void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) 330 { 331 mpol_rebind_policy(tsk->mempolicy, new); 332 } 333 334 /* 335 * Rebind each vma in mm to new nodemask. 336 * 337 * Call holding a reference to mm. Takes mm->mmap_sem during call. 338 */ 339 340 void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) 341 { 342 struct vm_area_struct *vma; 343 344 down_write(&mm->mmap_sem); 345 for (vma = mm->mmap; vma; vma = vma->vm_next) 346 mpol_rebind_policy(vma->vm_policy, new); 347 up_write(&mm->mmap_sem); 348 } 349 350 static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { 351 [MPOL_DEFAULT] = { 352 .rebind = mpol_rebind_default, 353 }, 354 [MPOL_INTERLEAVE] = { 355 .create = mpol_new_interleave, 356 .rebind = mpol_rebind_nodemask, 357 }, 358 [MPOL_PREFERRED] = { 359 .create = mpol_new_preferred, 360 .rebind = mpol_rebind_preferred, 361 }, 362 [MPOL_BIND] = { 363 .create = mpol_new_bind, 364 .rebind = mpol_rebind_nodemask, 365 }, 366 }; 367 368 static void gather_stats(struct page *, void *, int pte_dirty); 369 static void migrate_page_add(struct page *page, struct list_head *pagelist, 370 unsigned long flags); 371 372 /* Scan through pages checking if pages follow certain conditions. */ 373 static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 374 unsigned long addr, unsigned long end, 375 const nodemask_t *nodes, unsigned long flags, 376 void *private) 377 { 378 pte_t *orig_pte; 379 pte_t *pte; 380 spinlock_t *ptl; 381 382 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 383 do { 384 struct page *page; 385 int nid; 386 387 if (!pte_present(*pte)) 388 continue; 389 page = vm_normal_page(vma, addr, *pte); 390 if (!page) 391 continue; 392 /* 393 * The check for PageReserved here is important to avoid 394 * handling zero pages and other pages that may have been 395 * marked special by the system. 396 * 397 * If the PageReserved would not be checked here then f.e. 398 * the location of the zero page could have an influence 399 * on MPOL_MF_STRICT, zero pages would be counted for 400 * the per node stats, and there would be useless attempts 401 * to put zero pages on the migration list. 402 */ 403 if (PageReserved(page)) 404 continue; 405 nid = page_to_nid(page); 406 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) 407 continue; 408 409 if (flags & MPOL_MF_STATS) 410 gather_stats(page, private, pte_dirty(*pte)); 411 else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) 412 migrate_page_add(page, private, flags); 413 else 414 break; 415 } while (pte++, addr += PAGE_SIZE, addr != end); 416 pte_unmap_unlock(orig_pte, ptl); 417 return addr != end; 418 } 419 420 static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, 421 unsigned long addr, unsigned long end, 422 const nodemask_t *nodes, unsigned long flags, 423 void *private) 424 { 425 pmd_t *pmd; 426 unsigned long next; 427 428 pmd = pmd_offset(pud, addr); 429 do { 430 next = pmd_addr_end(addr, end); 431 if (pmd_none_or_clear_bad(pmd)) 432 continue; 433 if (check_pte_range(vma, pmd, addr, next, nodes, 434 flags, private)) 435 return -EIO; 436 } while (pmd++, addr = next, addr != end); 437 return 0; 438 } 439 440 static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, 441 unsigned long addr, unsigned long end, 442 const nodemask_t *nodes, unsigned long flags, 443 void *private) 444 { 445 pud_t *pud; 446 unsigned long next; 447 448 pud = pud_offset(pgd, addr); 449 do { 450 next = pud_addr_end(addr, end); 451 if (pud_none_or_clear_bad(pud)) 452 continue; 453 if (check_pmd_range(vma, pud, addr, next, nodes, 454 flags, private)) 455 return -EIO; 456 } while (pud++, addr = next, addr != end); 457 return 0; 458 } 459 460 static inline int check_pgd_range(struct vm_area_struct *vma, 461 unsigned long addr, unsigned long end, 462 const nodemask_t *nodes, unsigned long flags, 463 void *private) 464 { 465 pgd_t *pgd; 466 unsigned long next; 467 468 pgd = pgd_offset(vma->vm_mm, addr); 469 do { 470 next = pgd_addr_end(addr, end); 471 if (pgd_none_or_clear_bad(pgd)) 472 continue; 473 if (check_pud_range(vma, pgd, addr, next, nodes, 474 flags, private)) 475 return -EIO; 476 } while (pgd++, addr = next, addr != end); 477 return 0; 478 } 479 480 /* 481 * Check if all pages in a range are on a set of nodes. 482 * If pagelist != NULL then isolate pages from the LRU and 483 * put them on the pagelist. 484 */ 485 static struct vm_area_struct * 486 check_range(struct mm_struct *mm, unsigned long start, unsigned long end, 487 const nodemask_t *nodes, unsigned long flags, void *private) 488 { 489 int err; 490 struct vm_area_struct *first, *vma, *prev; 491 492 493 first = find_vma(mm, start); 494 if (!first) 495 return ERR_PTR(-EFAULT); 496 prev = NULL; 497 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { 498 if (!(flags & MPOL_MF_DISCONTIG_OK)) { 499 if (!vma->vm_next && vma->vm_end < end) 500 return ERR_PTR(-EFAULT); 501 if (prev && prev->vm_end < vma->vm_start) 502 return ERR_PTR(-EFAULT); 503 } 504 if (!is_vm_hugetlb_page(vma) && 505 ((flags & MPOL_MF_STRICT) || 506 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && 507 vma_migratable(vma)))) { 508 unsigned long endvma = vma->vm_end; 509 510 if (endvma > end) 511 endvma = end; 512 if (vma->vm_start > start) 513 start = vma->vm_start; 514 err = check_pgd_range(vma, start, endvma, nodes, 515 flags, private); 516 if (err) { 517 first = ERR_PTR(err); 518 break; 519 } 520 } 521 prev = vma; 522 } 523 return first; 524 } 525 526 /* Apply policy to a single VMA */ 527 static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) 528 { 529 int err = 0; 530 struct mempolicy *old = vma->vm_policy; 531 532 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", 533 vma->vm_start, vma->vm_end, vma->vm_pgoff, 534 vma->vm_ops, vma->vm_file, 535 vma->vm_ops ? vma->vm_ops->set_policy : NULL); 536 537 if (vma->vm_ops && vma->vm_ops->set_policy) 538 err = vma->vm_ops->set_policy(vma, new); 539 if (!err) { 540 mpol_get(new); 541 vma->vm_policy = new; 542 mpol_put(old); 543 } 544 return err; 545 } 546 547 /* Step 2: apply policy to a range and do splits. */ 548 static int mbind_range(struct vm_area_struct *vma, unsigned long start, 549 unsigned long end, struct mempolicy *new) 550 { 551 struct vm_area_struct *next; 552 int err; 553 554 err = 0; 555 for (; vma && vma->vm_start < end; vma = next) { 556 next = vma->vm_next; 557 if (vma->vm_start < start) 558 err = split_vma(vma->vm_mm, vma, start, 1); 559 if (!err && vma->vm_end > end) 560 err = split_vma(vma->vm_mm, vma, end, 0); 561 if (!err) 562 err = policy_vma(vma, new); 563 if (err) 564 break; 565 } 566 return err; 567 } 568 569 /* 570 * Update task->flags PF_MEMPOLICY bit: set iff non-default 571 * mempolicy. Allows more rapid checking of this (combined perhaps 572 * with other PF_* flag bits) on memory allocation hot code paths. 573 * 574 * If called from outside this file, the task 'p' should -only- be 575 * a newly forked child not yet visible on the task list, because 576 * manipulating the task flags of a visible task is not safe. 577 * 578 * The above limitation is why this routine has the funny name 579 * mpol_fix_fork_child_flag(). 580 * 581 * It is also safe to call this with a task pointer of current, 582 * which the static wrapper mpol_set_task_struct_flag() does, 583 * for use within this file. 584 */ 585 586 void mpol_fix_fork_child_flag(struct task_struct *p) 587 { 588 if (p->mempolicy) 589 p->flags |= PF_MEMPOLICY; 590 else 591 p->flags &= ~PF_MEMPOLICY; 592 } 593 594 static void mpol_set_task_struct_flag(void) 595 { 596 mpol_fix_fork_child_flag(current); 597 } 598 599 /* Set the process memory policy */ 600 static long do_set_mempolicy(unsigned short mode, unsigned short flags, 601 nodemask_t *nodes) 602 { 603 struct mempolicy *new; 604 struct mm_struct *mm = current->mm; 605 606 new = mpol_new(mode, flags, nodes); 607 if (IS_ERR(new)) 608 return PTR_ERR(new); 609 610 /* 611 * prevent changing our mempolicy while show_numa_maps() 612 * is using it. 613 * Note: do_set_mempolicy() can be called at init time 614 * with no 'mm'. 615 */ 616 if (mm) 617 down_write(&mm->mmap_sem); 618 mpol_put(current->mempolicy); 619 current->mempolicy = new; 620 mpol_set_task_struct_flag(); 621 if (new && new->mode == MPOL_INTERLEAVE && 622 nodes_weight(new->v.nodes)) 623 current->il_next = first_node(new->v.nodes); 624 if (mm) 625 up_write(&mm->mmap_sem); 626 627 return 0; 628 } 629 630 /* 631 * Return nodemask for policy for get_mempolicy() query 632 */ 633 static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) 634 { 635 nodes_clear(*nodes); 636 if (p == &default_policy) 637 return; 638 639 switch (p->mode) { 640 case MPOL_BIND: 641 /* Fall through */ 642 case MPOL_INTERLEAVE: 643 *nodes = p->v.nodes; 644 break; 645 case MPOL_PREFERRED: 646 if (!(p->flags & MPOL_F_LOCAL)) 647 node_set(p->v.preferred_node, *nodes); 648 /* else return empty node mask for local allocation */ 649 break; 650 default: 651 BUG(); 652 } 653 } 654 655 static int lookup_node(struct mm_struct *mm, unsigned long addr) 656 { 657 struct page *p; 658 int err; 659 660 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); 661 if (err >= 0) { 662 err = page_to_nid(p); 663 put_page(p); 664 } 665 return err; 666 } 667 668 /* Retrieve NUMA policy */ 669 static long do_get_mempolicy(int *policy, nodemask_t *nmask, 670 unsigned long addr, unsigned long flags) 671 { 672 int err; 673 struct mm_struct *mm = current->mm; 674 struct vm_area_struct *vma = NULL; 675 struct mempolicy *pol = current->mempolicy; 676 677 cpuset_update_task_memory_state(); 678 if (flags & 679 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) 680 return -EINVAL; 681 682 if (flags & MPOL_F_MEMS_ALLOWED) { 683 if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) 684 return -EINVAL; 685 *policy = 0; /* just so it's initialized */ 686 *nmask = cpuset_current_mems_allowed; 687 return 0; 688 } 689 690 if (flags & MPOL_F_ADDR) { 691 /* 692 * Do NOT fall back to task policy if the 693 * vma/shared policy at addr is NULL. We 694 * want to return MPOL_DEFAULT in this case. 695 */ 696 down_read(&mm->mmap_sem); 697 vma = find_vma_intersection(mm, addr, addr+1); 698 if (!vma) { 699 up_read(&mm->mmap_sem); 700 return -EFAULT; 701 } 702 if (vma->vm_ops && vma->vm_ops->get_policy) 703 pol = vma->vm_ops->get_policy(vma, addr); 704 else 705 pol = vma->vm_policy; 706 } else if (addr) 707 return -EINVAL; 708 709 if (!pol) 710 pol = &default_policy; /* indicates default behavior */ 711 712 if (flags & MPOL_F_NODE) { 713 if (flags & MPOL_F_ADDR) { 714 err = lookup_node(mm, addr); 715 if (err < 0) 716 goto out; 717 *policy = err; 718 } else if (pol == current->mempolicy && 719 pol->mode == MPOL_INTERLEAVE) { 720 *policy = current->il_next; 721 } else { 722 err = -EINVAL; 723 goto out; 724 } 725 } else { 726 *policy = pol == &default_policy ? MPOL_DEFAULT : 727 pol->mode; 728 /* 729 * Internal mempolicy flags must be masked off before exposing 730 * the policy to userspace. 731 */ 732 *policy |= (pol->flags & MPOL_MODE_FLAGS); 733 } 734 735 if (vma) { 736 up_read(¤t->mm->mmap_sem); 737 vma = NULL; 738 } 739 740 err = 0; 741 if (nmask) 742 get_policy_nodemask(pol, nmask); 743 744 out: 745 mpol_cond_put(pol); 746 if (vma) 747 up_read(¤t->mm->mmap_sem); 748 return err; 749 } 750 751 #ifdef CONFIG_MIGRATION 752 /* 753 * page migration 754 */ 755 static void migrate_page_add(struct page *page, struct list_head *pagelist, 756 unsigned long flags) 757 { 758 /* 759 * Avoid migrating a page that is shared with others. 760 */ 761 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { 762 if (!isolate_lru_page(page)) { 763 list_add_tail(&page->lru, pagelist); 764 } 765 } 766 } 767 768 static struct page *new_node_page(struct page *page, unsigned long node, int **x) 769 { 770 return alloc_pages_node(node, GFP_HIGHUSER_MOVABLE, 0); 771 } 772 773 /* 774 * Migrate pages from one node to a target node. 775 * Returns error or the number of pages not migrated. 776 */ 777 static int migrate_to_node(struct mm_struct *mm, int source, int dest, 778 int flags) 779 { 780 nodemask_t nmask; 781 LIST_HEAD(pagelist); 782 int err = 0; 783 784 nodes_clear(nmask); 785 node_set(source, nmask); 786 787 check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask, 788 flags | MPOL_MF_DISCONTIG_OK, &pagelist); 789 790 if (!list_empty(&pagelist)) 791 err = migrate_pages(&pagelist, new_node_page, dest); 792 793 return err; 794 } 795 796 /* 797 * Move pages between the two nodesets so as to preserve the physical 798 * layout as much as possible. 799 * 800 * Returns the number of page that could not be moved. 801 */ 802 int do_migrate_pages(struct mm_struct *mm, 803 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) 804 { 805 int busy = 0; 806 int err; 807 nodemask_t tmp; 808 809 err = migrate_prep(); 810 if (err) 811 return err; 812 813 down_read(&mm->mmap_sem); 814 815 err = migrate_vmas(mm, from_nodes, to_nodes, flags); 816 if (err) 817 goto out; 818 819 /* 820 * Find a 'source' bit set in 'tmp' whose corresponding 'dest' 821 * bit in 'to' is not also set in 'tmp'. Clear the found 'source' 822 * bit in 'tmp', and return that <source, dest> pair for migration. 823 * The pair of nodemasks 'to' and 'from' define the map. 824 * 825 * If no pair of bits is found that way, fallback to picking some 826 * pair of 'source' and 'dest' bits that are not the same. If the 827 * 'source' and 'dest' bits are the same, this represents a node 828 * that will be migrating to itself, so no pages need move. 829 * 830 * If no bits are left in 'tmp', or if all remaining bits left 831 * in 'tmp' correspond to the same bit in 'to', return false 832 * (nothing left to migrate). 833 * 834 * This lets us pick a pair of nodes to migrate between, such that 835 * if possible the dest node is not already occupied by some other 836 * source node, minimizing the risk of overloading the memory on a 837 * node that would happen if we migrated incoming memory to a node 838 * before migrating outgoing memory source that same node. 839 * 840 * A single scan of tmp is sufficient. As we go, we remember the 841 * most recent <s, d> pair that moved (s != d). If we find a pair 842 * that not only moved, but what's better, moved to an empty slot 843 * (d is not set in tmp), then we break out then, with that pair. 844 * Otherwise when we finish scannng from_tmp, we at least have the 845 * most recent <s, d> pair that moved. If we get all the way through 846 * the scan of tmp without finding any node that moved, much less 847 * moved to an empty node, then there is nothing left worth migrating. 848 */ 849 850 tmp = *from_nodes; 851 while (!nodes_empty(tmp)) { 852 int s,d; 853 int source = -1; 854 int dest = 0; 855 856 for_each_node_mask(s, tmp) { 857 d = node_remap(s, *from_nodes, *to_nodes); 858 if (s == d) 859 continue; 860 861 source = s; /* Node moved. Memorize */ 862 dest = d; 863 864 /* dest not in remaining from nodes? */ 865 if (!node_isset(dest, tmp)) 866 break; 867 } 868 if (source == -1) 869 break; 870 871 node_clear(source, tmp); 872 err = migrate_to_node(mm, source, dest, flags); 873 if (err > 0) 874 busy += err; 875 if (err < 0) 876 break; 877 } 878 out: 879 up_read(&mm->mmap_sem); 880 if (err < 0) 881 return err; 882 return busy; 883 884 } 885 886 /* 887 * Allocate a new page for page migration based on vma policy. 888 * Start assuming that page is mapped by vma pointed to by @private. 889 * Search forward from there, if not. N.B., this assumes that the 890 * list of pages handed to migrate_pages()--which is how we get here-- 891 * is in virtual address order. 892 */ 893 static struct page *new_vma_page(struct page *page, unsigned long private, int **x) 894 { 895 struct vm_area_struct *vma = (struct vm_area_struct *)private; 896 unsigned long uninitialized_var(address); 897 898 while (vma) { 899 address = page_address_in_vma(page, vma); 900 if (address != -EFAULT) 901 break; 902 vma = vma->vm_next; 903 } 904 905 /* 906 * if !vma, alloc_page_vma() will use task or system default policy 907 */ 908 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); 909 } 910 #else 911 912 static void migrate_page_add(struct page *page, struct list_head *pagelist, 913 unsigned long flags) 914 { 915 } 916 917 int do_migrate_pages(struct mm_struct *mm, 918 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) 919 { 920 return -ENOSYS; 921 } 922 923 static struct page *new_vma_page(struct page *page, unsigned long private, int **x) 924 { 925 return NULL; 926 } 927 #endif 928 929 static long do_mbind(unsigned long start, unsigned long len, 930 unsigned short mode, unsigned short mode_flags, 931 nodemask_t *nmask, unsigned long flags) 932 { 933 struct vm_area_struct *vma; 934 struct mm_struct *mm = current->mm; 935 struct mempolicy *new; 936 unsigned long end; 937 int err; 938 LIST_HEAD(pagelist); 939 940 if (flags & ~(unsigned long)(MPOL_MF_STRICT | 941 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) 942 return -EINVAL; 943 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) 944 return -EPERM; 945 946 if (start & ~PAGE_MASK) 947 return -EINVAL; 948 949 if (mode == MPOL_DEFAULT) 950 flags &= ~MPOL_MF_STRICT; 951 952 len = (len + PAGE_SIZE - 1) & PAGE_MASK; 953 end = start + len; 954 955 if (end < start) 956 return -EINVAL; 957 if (end == start) 958 return 0; 959 960 new = mpol_new(mode, mode_flags, nmask); 961 if (IS_ERR(new)) 962 return PTR_ERR(new); 963 964 /* 965 * If we are using the default policy then operation 966 * on discontinuous address spaces is okay after all 967 */ 968 if (!new) 969 flags |= MPOL_MF_DISCONTIG_OK; 970 971 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", 972 start, start + len, mode, mode_flags, 973 nmask ? nodes_addr(*nmask)[0] : -1); 974 975 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { 976 977 err = migrate_prep(); 978 if (err) 979 return err; 980 } 981 down_write(&mm->mmap_sem); 982 vma = check_range(mm, start, end, nmask, 983 flags | MPOL_MF_INVERT, &pagelist); 984 985 err = PTR_ERR(vma); 986 if (!IS_ERR(vma)) { 987 int nr_failed = 0; 988 989 err = mbind_range(vma, start, end, new); 990 991 if (!list_empty(&pagelist)) 992 nr_failed = migrate_pages(&pagelist, new_vma_page, 993 (unsigned long)vma); 994 995 if (!err && nr_failed && (flags & MPOL_MF_STRICT)) 996 err = -EIO; 997 } 998 999 up_write(&mm->mmap_sem); 1000 mpol_put(new); 1001 return err; 1002 } 1003 1004 /* 1005 * User space interface with variable sized bitmaps for nodelists. 1006 */ 1007 1008 /* Copy a node mask from user space. */ 1009 static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, 1010 unsigned long maxnode) 1011 { 1012 unsigned long k; 1013 unsigned long nlongs; 1014 unsigned long endmask; 1015 1016 --maxnode; 1017 nodes_clear(*nodes); 1018 if (maxnode == 0 || !nmask) 1019 return 0; 1020 if (maxnode > PAGE_SIZE*BITS_PER_BYTE) 1021 return -EINVAL; 1022 1023 nlongs = BITS_TO_LONGS(maxnode); 1024 if ((maxnode % BITS_PER_LONG) == 0) 1025 endmask = ~0UL; 1026 else 1027 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; 1028 1029 /* When the user specified more nodes than supported just check 1030 if the non supported part is all zero. */ 1031 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { 1032 if (nlongs > PAGE_SIZE/sizeof(long)) 1033 return -EINVAL; 1034 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { 1035 unsigned long t; 1036 if (get_user(t, nmask + k)) 1037 return -EFAULT; 1038 if (k == nlongs - 1) { 1039 if (t & endmask) 1040 return -EINVAL; 1041 } else if (t) 1042 return -EINVAL; 1043 } 1044 nlongs = BITS_TO_LONGS(MAX_NUMNODES); 1045 endmask = ~0UL; 1046 } 1047 1048 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) 1049 return -EFAULT; 1050 nodes_addr(*nodes)[nlongs-1] &= endmask; 1051 return 0; 1052 } 1053 1054 /* Copy a kernel node mask to user space */ 1055 static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, 1056 nodemask_t *nodes) 1057 { 1058 unsigned long copy = ALIGN(maxnode-1, 64) / 8; 1059 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); 1060 1061 if (copy > nbytes) { 1062 if (copy > PAGE_SIZE) 1063 return -EINVAL; 1064 if (clear_user((char __user *)mask + nbytes, copy - nbytes)) 1065 return -EFAULT; 1066 copy = nbytes; 1067 } 1068 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; 1069 } 1070 1071 asmlinkage long sys_mbind(unsigned long start, unsigned long len, 1072 unsigned long mode, 1073 unsigned long __user *nmask, unsigned long maxnode, 1074 unsigned flags) 1075 { 1076 nodemask_t nodes; 1077 int err; 1078 unsigned short mode_flags; 1079 1080 mode_flags = mode & MPOL_MODE_FLAGS; 1081 mode &= ~MPOL_MODE_FLAGS; 1082 if (mode >= MPOL_MAX) 1083 return -EINVAL; 1084 if ((mode_flags & MPOL_F_STATIC_NODES) && 1085 (mode_flags & MPOL_F_RELATIVE_NODES)) 1086 return -EINVAL; 1087 err = get_nodes(&nodes, nmask, maxnode); 1088 if (err) 1089 return err; 1090 return do_mbind(start, len, mode, mode_flags, &nodes, flags); 1091 } 1092 1093 /* Set the process memory policy */ 1094 asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, 1095 unsigned long maxnode) 1096 { 1097 int err; 1098 nodemask_t nodes; 1099 unsigned short flags; 1100 1101 flags = mode & MPOL_MODE_FLAGS; 1102 mode &= ~MPOL_MODE_FLAGS; 1103 if ((unsigned int)mode >= MPOL_MAX) 1104 return -EINVAL; 1105 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) 1106 return -EINVAL; 1107 err = get_nodes(&nodes, nmask, maxnode); 1108 if (err) 1109 return err; 1110 return do_set_mempolicy(mode, flags, &nodes); 1111 } 1112 1113 asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, 1114 const unsigned long __user *old_nodes, 1115 const unsigned long __user *new_nodes) 1116 { 1117 struct mm_struct *mm; 1118 struct task_struct *task; 1119 nodemask_t old; 1120 nodemask_t new; 1121 nodemask_t task_nodes; 1122 int err; 1123 1124 err = get_nodes(&old, old_nodes, maxnode); 1125 if (err) 1126 return err; 1127 1128 err = get_nodes(&new, new_nodes, maxnode); 1129 if (err) 1130 return err; 1131 1132 /* Find the mm_struct */ 1133 read_lock(&tasklist_lock); 1134 task = pid ? find_task_by_vpid(pid) : current; 1135 if (!task) { 1136 read_unlock(&tasklist_lock); 1137 return -ESRCH; 1138 } 1139 mm = get_task_mm(task); 1140 read_unlock(&tasklist_lock); 1141 1142 if (!mm) 1143 return -EINVAL; 1144 1145 /* 1146 * Check if this process has the right to modify the specified 1147 * process. The right exists if the process has administrative 1148 * capabilities, superuser privileges or the same 1149 * userid as the target process. 1150 */ 1151 if ((current->euid != task->suid) && (current->euid != task->uid) && 1152 (current->uid != task->suid) && (current->uid != task->uid) && 1153 !capable(CAP_SYS_NICE)) { 1154 err = -EPERM; 1155 goto out; 1156 } 1157 1158 task_nodes = cpuset_mems_allowed(task); 1159 /* Is the user allowed to access the target nodes? */ 1160 if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) { 1161 err = -EPERM; 1162 goto out; 1163 } 1164 1165 if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) { 1166 err = -EINVAL; 1167 goto out; 1168 } 1169 1170 err = security_task_movememory(task); 1171 if (err) 1172 goto out; 1173 1174 err = do_migrate_pages(mm, &old, &new, 1175 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); 1176 out: 1177 mmput(mm); 1178 return err; 1179 } 1180 1181 1182 /* Retrieve NUMA policy */ 1183 asmlinkage long sys_get_mempolicy(int __user *policy, 1184 unsigned long __user *nmask, 1185 unsigned long maxnode, 1186 unsigned long addr, unsigned long flags) 1187 { 1188 int err; 1189 int uninitialized_var(pval); 1190 nodemask_t nodes; 1191 1192 if (nmask != NULL && maxnode < MAX_NUMNODES) 1193 return -EINVAL; 1194 1195 err = do_get_mempolicy(&pval, &nodes, addr, flags); 1196 1197 if (err) 1198 return err; 1199 1200 if (policy && put_user(pval, policy)) 1201 return -EFAULT; 1202 1203 if (nmask) 1204 err = copy_nodes_to_user(nmask, maxnode, &nodes); 1205 1206 return err; 1207 } 1208 1209 #ifdef CONFIG_COMPAT 1210 1211 asmlinkage long compat_sys_get_mempolicy(int __user *policy, 1212 compat_ulong_t __user *nmask, 1213 compat_ulong_t maxnode, 1214 compat_ulong_t addr, compat_ulong_t flags) 1215 { 1216 long err; 1217 unsigned long __user *nm = NULL; 1218 unsigned long nr_bits, alloc_size; 1219 DECLARE_BITMAP(bm, MAX_NUMNODES); 1220 1221 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 1222 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 1223 1224 if (nmask) 1225 nm = compat_alloc_user_space(alloc_size); 1226 1227 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); 1228 1229 if (!err && nmask) { 1230 err = copy_from_user(bm, nm, alloc_size); 1231 /* ensure entire bitmap is zeroed */ 1232 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); 1233 err |= compat_put_bitmap(nmask, bm, nr_bits); 1234 } 1235 1236 return err; 1237 } 1238 1239 asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, 1240 compat_ulong_t maxnode) 1241 { 1242 long err = 0; 1243 unsigned long __user *nm = NULL; 1244 unsigned long nr_bits, alloc_size; 1245 DECLARE_BITMAP(bm, MAX_NUMNODES); 1246 1247 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 1248 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 1249 1250 if (nmask) { 1251 err = compat_get_bitmap(bm, nmask, nr_bits); 1252 nm = compat_alloc_user_space(alloc_size); 1253 err |= copy_to_user(nm, bm, alloc_size); 1254 } 1255 1256 if (err) 1257 return -EFAULT; 1258 1259 return sys_set_mempolicy(mode, nm, nr_bits+1); 1260 } 1261 1262 asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, 1263 compat_ulong_t mode, compat_ulong_t __user *nmask, 1264 compat_ulong_t maxnode, compat_ulong_t flags) 1265 { 1266 long err = 0; 1267 unsigned long __user *nm = NULL; 1268 unsigned long nr_bits, alloc_size; 1269 nodemask_t bm; 1270 1271 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 1272 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 1273 1274 if (nmask) { 1275 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); 1276 nm = compat_alloc_user_space(alloc_size); 1277 err |= copy_to_user(nm, nodes_addr(bm), alloc_size); 1278 } 1279 1280 if (err) 1281 return -EFAULT; 1282 1283 return sys_mbind(start, len, mode, nm, nr_bits+1, flags); 1284 } 1285 1286 #endif 1287 1288 /* 1289 * get_vma_policy(@task, @vma, @addr) 1290 * @task - task for fallback if vma policy == default 1291 * @vma - virtual memory area whose policy is sought 1292 * @addr - address in @vma for shared policy lookup 1293 * 1294 * Returns effective policy for a VMA at specified address. 1295 * Falls back to @task or system default policy, as necessary. 1296 * Current or other task's task mempolicy and non-shared vma policies 1297 * are protected by the task's mmap_sem, which must be held for read by 1298 * the caller. 1299 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference 1300 * count--added by the get_policy() vm_op, as appropriate--to protect against 1301 * freeing by another task. It is the caller's responsibility to free the 1302 * extra reference for shared policies. 1303 */ 1304 static struct mempolicy *get_vma_policy(struct task_struct *task, 1305 struct vm_area_struct *vma, unsigned long addr) 1306 { 1307 struct mempolicy *pol = task->mempolicy; 1308 1309 if (vma) { 1310 if (vma->vm_ops && vma->vm_ops->get_policy) { 1311 struct mempolicy *vpol = vma->vm_ops->get_policy(vma, 1312 addr); 1313 if (vpol) 1314 pol = vpol; 1315 } else if (vma->vm_policy) 1316 pol = vma->vm_policy; 1317 } 1318 if (!pol) 1319 pol = &default_policy; 1320 return pol; 1321 } 1322 1323 /* 1324 * Return a nodemask representing a mempolicy for filtering nodes for 1325 * page allocation 1326 */ 1327 static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) 1328 { 1329 /* Lower zones don't get a nodemask applied for MPOL_BIND */ 1330 if (unlikely(policy->mode == MPOL_BIND) && 1331 gfp_zone(gfp) >= policy_zone && 1332 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) 1333 return &policy->v.nodes; 1334 1335 return NULL; 1336 } 1337 1338 /* Return a zonelist indicated by gfp for node representing a mempolicy */ 1339 static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy) 1340 { 1341 int nd = numa_node_id(); 1342 1343 switch (policy->mode) { 1344 case MPOL_PREFERRED: 1345 if (!(policy->flags & MPOL_F_LOCAL)) 1346 nd = policy->v.preferred_node; 1347 break; 1348 case MPOL_BIND: 1349 /* 1350 * Normally, MPOL_BIND allocations are node-local within the 1351 * allowed nodemask. However, if __GFP_THISNODE is set and the 1352 * current node is part of the mask, we use the zonelist for 1353 * the first node in the mask instead. 1354 */ 1355 if (unlikely(gfp & __GFP_THISNODE) && 1356 unlikely(!node_isset(nd, policy->v.nodes))) 1357 nd = first_node(policy->v.nodes); 1358 break; 1359 case MPOL_INTERLEAVE: /* should not happen */ 1360 break; 1361 default: 1362 BUG(); 1363 } 1364 return node_zonelist(nd, gfp); 1365 } 1366 1367 /* Do dynamic interleaving for a process */ 1368 static unsigned interleave_nodes(struct mempolicy *policy) 1369 { 1370 unsigned nid, next; 1371 struct task_struct *me = current; 1372 1373 nid = me->il_next; 1374 next = next_node(nid, policy->v.nodes); 1375 if (next >= MAX_NUMNODES) 1376 next = first_node(policy->v.nodes); 1377 if (next < MAX_NUMNODES) 1378 me->il_next = next; 1379 return nid; 1380 } 1381 1382 /* 1383 * Depending on the memory policy provide a node from which to allocate the 1384 * next slab entry. 1385 * @policy must be protected by freeing by the caller. If @policy is 1386 * the current task's mempolicy, this protection is implicit, as only the 1387 * task can change it's policy. The system default policy requires no 1388 * such protection. 1389 */ 1390 unsigned slab_node(struct mempolicy *policy) 1391 { 1392 if (!policy || policy->flags & MPOL_F_LOCAL) 1393 return numa_node_id(); 1394 1395 switch (policy->mode) { 1396 case MPOL_PREFERRED: 1397 /* 1398 * handled MPOL_F_LOCAL above 1399 */ 1400 return policy->v.preferred_node; 1401 1402 case MPOL_INTERLEAVE: 1403 return interleave_nodes(policy); 1404 1405 case MPOL_BIND: { 1406 /* 1407 * Follow bind policy behavior and start allocation at the 1408 * first node. 1409 */ 1410 struct zonelist *zonelist; 1411 struct zone *zone; 1412 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); 1413 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0]; 1414 (void)first_zones_zonelist(zonelist, highest_zoneidx, 1415 &policy->v.nodes, 1416 &zone); 1417 return zone->node; 1418 } 1419 1420 default: 1421 BUG(); 1422 } 1423 } 1424 1425 /* Do static interleaving for a VMA with known offset. */ 1426 static unsigned offset_il_node(struct mempolicy *pol, 1427 struct vm_area_struct *vma, unsigned long off) 1428 { 1429 unsigned nnodes = nodes_weight(pol->v.nodes); 1430 unsigned target; 1431 int c; 1432 int nid = -1; 1433 1434 if (!nnodes) 1435 return numa_node_id(); 1436 target = (unsigned int)off % nnodes; 1437 c = 0; 1438 do { 1439 nid = next_node(nid, pol->v.nodes); 1440 c++; 1441 } while (c <= target); 1442 return nid; 1443 } 1444 1445 /* Determine a node number for interleave */ 1446 static inline unsigned interleave_nid(struct mempolicy *pol, 1447 struct vm_area_struct *vma, unsigned long addr, int shift) 1448 { 1449 if (vma) { 1450 unsigned long off; 1451 1452 /* 1453 * for small pages, there is no difference between 1454 * shift and PAGE_SHIFT, so the bit-shift is safe. 1455 * for huge pages, since vm_pgoff is in units of small 1456 * pages, we need to shift off the always 0 bits to get 1457 * a useful offset. 1458 */ 1459 BUG_ON(shift < PAGE_SHIFT); 1460 off = vma->vm_pgoff >> (shift - PAGE_SHIFT); 1461 off += (addr - vma->vm_start) >> shift; 1462 return offset_il_node(pol, vma, off); 1463 } else 1464 return interleave_nodes(pol); 1465 } 1466 1467 #ifdef CONFIG_HUGETLBFS 1468 /* 1469 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) 1470 * @vma = virtual memory area whose policy is sought 1471 * @addr = address in @vma for shared policy lookup and interleave policy 1472 * @gfp_flags = for requested zone 1473 * @mpol = pointer to mempolicy pointer for reference counted mempolicy 1474 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask 1475 * 1476 * Returns a zonelist suitable for a huge page allocation and a pointer 1477 * to the struct mempolicy for conditional unref after allocation. 1478 * If the effective policy is 'BIND, returns a pointer to the mempolicy's 1479 * @nodemask for filtering the zonelist. 1480 */ 1481 struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, 1482 gfp_t gfp_flags, struct mempolicy **mpol, 1483 nodemask_t **nodemask) 1484 { 1485 struct zonelist *zl; 1486 1487 *mpol = get_vma_policy(current, vma, addr); 1488 *nodemask = NULL; /* assume !MPOL_BIND */ 1489 1490 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { 1491 zl = node_zonelist(interleave_nid(*mpol, vma, addr, 1492 huge_page_shift(hstate_vma(vma))), gfp_flags); 1493 } else { 1494 zl = policy_zonelist(gfp_flags, *mpol); 1495 if ((*mpol)->mode == MPOL_BIND) 1496 *nodemask = &(*mpol)->v.nodes; 1497 } 1498 return zl; 1499 } 1500 #endif 1501 1502 /* Allocate a page in interleaved policy. 1503 Own path because it needs to do special accounting. */ 1504 static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, 1505 unsigned nid) 1506 { 1507 struct zonelist *zl; 1508 struct page *page; 1509 1510 zl = node_zonelist(nid, gfp); 1511 page = __alloc_pages(gfp, order, zl); 1512 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) 1513 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); 1514 return page; 1515 } 1516 1517 /** 1518 * alloc_page_vma - Allocate a page for a VMA. 1519 * 1520 * @gfp: 1521 * %GFP_USER user allocation. 1522 * %GFP_KERNEL kernel allocations, 1523 * %GFP_HIGHMEM highmem/user allocations, 1524 * %GFP_FS allocation should not call back into a file system. 1525 * %GFP_ATOMIC don't sleep. 1526 * 1527 * @vma: Pointer to VMA or NULL if not available. 1528 * @addr: Virtual Address of the allocation. Must be inside the VMA. 1529 * 1530 * This function allocates a page from the kernel page pool and applies 1531 * a NUMA policy associated with the VMA or the current process. 1532 * When VMA is not NULL caller must hold down_read on the mmap_sem of the 1533 * mm_struct of the VMA to prevent it from going away. Should be used for 1534 * all allocations for pages that will be mapped into 1535 * user space. Returns NULL when no page can be allocated. 1536 * 1537 * Should be called with the mm_sem of the vma hold. 1538 */ 1539 struct page * 1540 alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) 1541 { 1542 struct mempolicy *pol = get_vma_policy(current, vma, addr); 1543 struct zonelist *zl; 1544 1545 cpuset_update_task_memory_state(); 1546 1547 if (unlikely(pol->mode == MPOL_INTERLEAVE)) { 1548 unsigned nid; 1549 1550 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT); 1551 mpol_cond_put(pol); 1552 return alloc_page_interleave(gfp, 0, nid); 1553 } 1554 zl = policy_zonelist(gfp, pol); 1555 if (unlikely(mpol_needs_cond_ref(pol))) { 1556 /* 1557 * slow path: ref counted shared policy 1558 */ 1559 struct page *page = __alloc_pages_nodemask(gfp, 0, 1560 zl, policy_nodemask(gfp, pol)); 1561 __mpol_put(pol); 1562 return page; 1563 } 1564 /* 1565 * fast path: default or task policy 1566 */ 1567 return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol)); 1568 } 1569 1570 /** 1571 * alloc_pages_current - Allocate pages. 1572 * 1573 * @gfp: 1574 * %GFP_USER user allocation, 1575 * %GFP_KERNEL kernel allocation, 1576 * %GFP_HIGHMEM highmem allocation, 1577 * %GFP_FS don't call back into a file system. 1578 * %GFP_ATOMIC don't sleep. 1579 * @order: Power of two of allocation size in pages. 0 is a single page. 1580 * 1581 * Allocate a page from the kernel page pool. When not in 1582 * interrupt context and apply the current process NUMA policy. 1583 * Returns NULL when no page can be allocated. 1584 * 1585 * Don't call cpuset_update_task_memory_state() unless 1586 * 1) it's ok to take cpuset_sem (can WAIT), and 1587 * 2) allocating for current task (not interrupt). 1588 */ 1589 struct page *alloc_pages_current(gfp_t gfp, unsigned order) 1590 { 1591 struct mempolicy *pol = current->mempolicy; 1592 1593 if ((gfp & __GFP_WAIT) && !in_interrupt()) 1594 cpuset_update_task_memory_state(); 1595 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) 1596 pol = &default_policy; 1597 1598 /* 1599 * No reference counting needed for current->mempolicy 1600 * nor system default_policy 1601 */ 1602 if (pol->mode == MPOL_INTERLEAVE) 1603 return alloc_page_interleave(gfp, order, interleave_nodes(pol)); 1604 return __alloc_pages_nodemask(gfp, order, 1605 policy_zonelist(gfp, pol), policy_nodemask(gfp, pol)); 1606 } 1607 EXPORT_SYMBOL(alloc_pages_current); 1608 1609 /* 1610 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it 1611 * rebinds the mempolicy its copying by calling mpol_rebind_policy() 1612 * with the mems_allowed returned by cpuset_mems_allowed(). This 1613 * keeps mempolicies cpuset relative after its cpuset moves. See 1614 * further kernel/cpuset.c update_nodemask(). 1615 */ 1616 1617 /* Slow path of a mempolicy duplicate */ 1618 struct mempolicy *__mpol_dup(struct mempolicy *old) 1619 { 1620 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); 1621 1622 if (!new) 1623 return ERR_PTR(-ENOMEM); 1624 if (current_cpuset_is_being_rebound()) { 1625 nodemask_t mems = cpuset_mems_allowed(current); 1626 mpol_rebind_policy(old, &mems); 1627 } 1628 *new = *old; 1629 atomic_set(&new->refcnt, 1); 1630 return new; 1631 } 1632 1633 /* 1634 * If *frompol needs [has] an extra ref, copy *frompol to *tompol , 1635 * eliminate the * MPOL_F_* flags that require conditional ref and 1636 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly 1637 * after return. Use the returned value. 1638 * 1639 * Allows use of a mempolicy for, e.g., multiple allocations with a single 1640 * policy lookup, even if the policy needs/has extra ref on lookup. 1641 * shmem_readahead needs this. 1642 */ 1643 struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol, 1644 struct mempolicy *frompol) 1645 { 1646 if (!mpol_needs_cond_ref(frompol)) 1647 return frompol; 1648 1649 *tompol = *frompol; 1650 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */ 1651 __mpol_put(frompol); 1652 return tompol; 1653 } 1654 1655 static int mpol_match_intent(const struct mempolicy *a, 1656 const struct mempolicy *b) 1657 { 1658 if (a->flags != b->flags) 1659 return 0; 1660 if (!mpol_store_user_nodemask(a)) 1661 return 1; 1662 return nodes_equal(a->w.user_nodemask, b->w.user_nodemask); 1663 } 1664 1665 /* Slow path of a mempolicy comparison */ 1666 int __mpol_equal(struct mempolicy *a, struct mempolicy *b) 1667 { 1668 if (!a || !b) 1669 return 0; 1670 if (a->mode != b->mode) 1671 return 0; 1672 if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b)) 1673 return 0; 1674 switch (a->mode) { 1675 case MPOL_BIND: 1676 /* Fall through */ 1677 case MPOL_INTERLEAVE: 1678 return nodes_equal(a->v.nodes, b->v.nodes); 1679 case MPOL_PREFERRED: 1680 return a->v.preferred_node == b->v.preferred_node && 1681 a->flags == b->flags; 1682 default: 1683 BUG(); 1684 return 0; 1685 } 1686 } 1687 1688 /* 1689 * Shared memory backing store policy support. 1690 * 1691 * Remember policies even when nobody has shared memory mapped. 1692 * The policies are kept in Red-Black tree linked from the inode. 1693 * They are protected by the sp->lock spinlock, which should be held 1694 * for any accesses to the tree. 1695 */ 1696 1697 /* lookup first element intersecting start-end */ 1698 /* Caller holds sp->lock */ 1699 static struct sp_node * 1700 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) 1701 { 1702 struct rb_node *n = sp->root.rb_node; 1703 1704 while (n) { 1705 struct sp_node *p = rb_entry(n, struct sp_node, nd); 1706 1707 if (start >= p->end) 1708 n = n->rb_right; 1709 else if (end <= p->start) 1710 n = n->rb_left; 1711 else 1712 break; 1713 } 1714 if (!n) 1715 return NULL; 1716 for (;;) { 1717 struct sp_node *w = NULL; 1718 struct rb_node *prev = rb_prev(n); 1719 if (!prev) 1720 break; 1721 w = rb_entry(prev, struct sp_node, nd); 1722 if (w->end <= start) 1723 break; 1724 n = prev; 1725 } 1726 return rb_entry(n, struct sp_node, nd); 1727 } 1728 1729 /* Insert a new shared policy into the list. */ 1730 /* Caller holds sp->lock */ 1731 static void sp_insert(struct shared_policy *sp, struct sp_node *new) 1732 { 1733 struct rb_node **p = &sp->root.rb_node; 1734 struct rb_node *parent = NULL; 1735 struct sp_node *nd; 1736 1737 while (*p) { 1738 parent = *p; 1739 nd = rb_entry(parent, struct sp_node, nd); 1740 if (new->start < nd->start) 1741 p = &(*p)->rb_left; 1742 else if (new->end > nd->end) 1743 p = &(*p)->rb_right; 1744 else 1745 BUG(); 1746 } 1747 rb_link_node(&new->nd, parent, p); 1748 rb_insert_color(&new->nd, &sp->root); 1749 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, 1750 new->policy ? new->policy->mode : 0); 1751 } 1752 1753 /* Find shared policy intersecting idx */ 1754 struct mempolicy * 1755 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) 1756 { 1757 struct mempolicy *pol = NULL; 1758 struct sp_node *sn; 1759 1760 if (!sp->root.rb_node) 1761 return NULL; 1762 spin_lock(&sp->lock); 1763 sn = sp_lookup(sp, idx, idx+1); 1764 if (sn) { 1765 mpol_get(sn->policy); 1766 pol = sn->policy; 1767 } 1768 spin_unlock(&sp->lock); 1769 return pol; 1770 } 1771 1772 static void sp_delete(struct shared_policy *sp, struct sp_node *n) 1773 { 1774 pr_debug("deleting %lx-l%lx\n", n->start, n->end); 1775 rb_erase(&n->nd, &sp->root); 1776 mpol_put(n->policy); 1777 kmem_cache_free(sn_cache, n); 1778 } 1779 1780 static struct sp_node *sp_alloc(unsigned long start, unsigned long end, 1781 struct mempolicy *pol) 1782 { 1783 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL); 1784 1785 if (!n) 1786 return NULL; 1787 n->start = start; 1788 n->end = end; 1789 mpol_get(pol); 1790 pol->flags |= MPOL_F_SHARED; /* for unref */ 1791 n->policy = pol; 1792 return n; 1793 } 1794 1795 /* Replace a policy range. */ 1796 static int shared_policy_replace(struct shared_policy *sp, unsigned long start, 1797 unsigned long end, struct sp_node *new) 1798 { 1799 struct sp_node *n, *new2 = NULL; 1800 1801 restart: 1802 spin_lock(&sp->lock); 1803 n = sp_lookup(sp, start, end); 1804 /* Take care of old policies in the same range. */ 1805 while (n && n->start < end) { 1806 struct rb_node *next = rb_next(&n->nd); 1807 if (n->start >= start) { 1808 if (n->end <= end) 1809 sp_delete(sp, n); 1810 else 1811 n->start = end; 1812 } else { 1813 /* Old policy spanning whole new range. */ 1814 if (n->end > end) { 1815 if (!new2) { 1816 spin_unlock(&sp->lock); 1817 new2 = sp_alloc(end, n->end, n->policy); 1818 if (!new2) 1819 return -ENOMEM; 1820 goto restart; 1821 } 1822 n->end = start; 1823 sp_insert(sp, new2); 1824 new2 = NULL; 1825 break; 1826 } else 1827 n->end = start; 1828 } 1829 if (!next) 1830 break; 1831 n = rb_entry(next, struct sp_node, nd); 1832 } 1833 if (new) 1834 sp_insert(sp, new); 1835 spin_unlock(&sp->lock); 1836 if (new2) { 1837 mpol_put(new2->policy); 1838 kmem_cache_free(sn_cache, new2); 1839 } 1840 return 0; 1841 } 1842 1843 /** 1844 * mpol_shared_policy_init - initialize shared policy for inode 1845 * @sp: pointer to inode shared policy 1846 * @mpol: struct mempolicy to install 1847 * 1848 * Install non-NULL @mpol in inode's shared policy rb-tree. 1849 * On entry, the current task has a reference on a non-NULL @mpol. 1850 * This must be released on exit. 1851 */ 1852 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) 1853 { 1854 sp->root = RB_ROOT; /* empty tree == default mempolicy */ 1855 spin_lock_init(&sp->lock); 1856 1857 if (mpol) { 1858 struct vm_area_struct pvma; 1859 struct mempolicy *new; 1860 1861 /* contextualize the tmpfs mount point mempolicy */ 1862 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); 1863 mpol_put(mpol); /* drop our ref on sb mpol */ 1864 if (IS_ERR(new)) 1865 return; /* no valid nodemask intersection */ 1866 1867 /* Create pseudo-vma that contains just the policy */ 1868 memset(&pvma, 0, sizeof(struct vm_area_struct)); 1869 pvma.vm_end = TASK_SIZE; /* policy covers entire file */ 1870 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ 1871 mpol_put(new); /* drop initial ref */ 1872 } 1873 } 1874 1875 int mpol_set_shared_policy(struct shared_policy *info, 1876 struct vm_area_struct *vma, struct mempolicy *npol) 1877 { 1878 int err; 1879 struct sp_node *new = NULL; 1880 unsigned long sz = vma_pages(vma); 1881 1882 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", 1883 vma->vm_pgoff, 1884 sz, npol ? npol->mode : -1, 1885 npol ? npol->flags : -1, 1886 npol ? nodes_addr(npol->v.nodes)[0] : -1); 1887 1888 if (npol) { 1889 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); 1890 if (!new) 1891 return -ENOMEM; 1892 } 1893 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); 1894 if (err && new) 1895 kmem_cache_free(sn_cache, new); 1896 return err; 1897 } 1898 1899 /* Free a backing policy store on inode delete. */ 1900 void mpol_free_shared_policy(struct shared_policy *p) 1901 { 1902 struct sp_node *n; 1903 struct rb_node *next; 1904 1905 if (!p->root.rb_node) 1906 return; 1907 spin_lock(&p->lock); 1908 next = rb_first(&p->root); 1909 while (next) { 1910 n = rb_entry(next, struct sp_node, nd); 1911 next = rb_next(&n->nd); 1912 rb_erase(&n->nd, &p->root); 1913 mpol_put(n->policy); 1914 kmem_cache_free(sn_cache, n); 1915 } 1916 spin_unlock(&p->lock); 1917 } 1918 1919 /* assumes fs == KERNEL_DS */ 1920 void __init numa_policy_init(void) 1921 { 1922 nodemask_t interleave_nodes; 1923 unsigned long largest = 0; 1924 int nid, prefer = 0; 1925 1926 policy_cache = kmem_cache_create("numa_policy", 1927 sizeof(struct mempolicy), 1928 0, SLAB_PANIC, NULL); 1929 1930 sn_cache = kmem_cache_create("shared_policy_node", 1931 sizeof(struct sp_node), 1932 0, SLAB_PANIC, NULL); 1933 1934 /* 1935 * Set interleaving policy for system init. Interleaving is only 1936 * enabled across suitably sized nodes (default is >= 16MB), or 1937 * fall back to the largest node if they're all smaller. 1938 */ 1939 nodes_clear(interleave_nodes); 1940 for_each_node_state(nid, N_HIGH_MEMORY) { 1941 unsigned long total_pages = node_present_pages(nid); 1942 1943 /* Preserve the largest node */ 1944 if (largest < total_pages) { 1945 largest = total_pages; 1946 prefer = nid; 1947 } 1948 1949 /* Interleave this node? */ 1950 if ((total_pages << PAGE_SHIFT) >= (16 << 20)) 1951 node_set(nid, interleave_nodes); 1952 } 1953 1954 /* All too small, use the largest */ 1955 if (unlikely(nodes_empty(interleave_nodes))) 1956 node_set(prefer, interleave_nodes); 1957 1958 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) 1959 printk("numa_policy_init: interleaving failed\n"); 1960 } 1961 1962 /* Reset policy of current process to default */ 1963 void numa_default_policy(void) 1964 { 1965 do_set_mempolicy(MPOL_DEFAULT, 0, NULL); 1966 } 1967 1968 /* 1969 * Parse and format mempolicy from/to strings 1970 */ 1971 1972 /* 1973 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag 1974 * Used only for mpol_parse_str() and mpol_to_str() 1975 */ 1976 #define MPOL_LOCAL (MPOL_INTERLEAVE + 1) 1977 static const char * const policy_types[] = 1978 { "default", "prefer", "bind", "interleave", "local" }; 1979 1980 1981 #ifdef CONFIG_TMPFS 1982 /** 1983 * mpol_parse_str - parse string to mempolicy 1984 * @str: string containing mempolicy to parse 1985 * @mpol: pointer to struct mempolicy pointer, returned on success. 1986 * @no_context: flag whether to "contextualize" the mempolicy 1987 * 1988 * Format of input: 1989 * <mode>[=<flags>][:<nodelist>] 1990 * 1991 * if @no_context is true, save the input nodemask in w.user_nodemask in 1992 * the returned mempolicy. This will be used to "clone" the mempolicy in 1993 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol 1994 * mount option. Note that if 'static' or 'relative' mode flags were 1995 * specified, the input nodemask will already have been saved. Saving 1996 * it again is redundant, but safe. 1997 * 1998 * On success, returns 0, else 1 1999 */ 2000 int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) 2001 { 2002 struct mempolicy *new = NULL; 2003 unsigned short uninitialized_var(mode); 2004 unsigned short uninitialized_var(mode_flags); 2005 nodemask_t nodes; 2006 char *nodelist = strchr(str, ':'); 2007 char *flags = strchr(str, '='); 2008 int i; 2009 int err = 1; 2010 2011 if (nodelist) { 2012 /* NUL-terminate mode or flags string */ 2013 *nodelist++ = '\0'; 2014 if (nodelist_parse(nodelist, nodes)) 2015 goto out; 2016 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY])) 2017 goto out; 2018 } else 2019 nodes_clear(nodes); 2020 2021 if (flags) 2022 *flags++ = '\0'; /* terminate mode string */ 2023 2024 for (i = 0; i <= MPOL_LOCAL; i++) { 2025 if (!strcmp(str, policy_types[i])) { 2026 mode = i; 2027 break; 2028 } 2029 } 2030 if (i > MPOL_LOCAL) 2031 goto out; 2032 2033 switch (mode) { 2034 case MPOL_PREFERRED: 2035 /* 2036 * Insist on a nodelist of one node only 2037 */ 2038 if (nodelist) { 2039 char *rest = nodelist; 2040 while (isdigit(*rest)) 2041 rest++; 2042 if (!*rest) 2043 err = 0; 2044 } 2045 break; 2046 case MPOL_INTERLEAVE: 2047 /* 2048 * Default to online nodes with memory if no nodelist 2049 */ 2050 if (!nodelist) 2051 nodes = node_states[N_HIGH_MEMORY]; 2052 err = 0; 2053 break; 2054 case MPOL_LOCAL: 2055 /* 2056 * Don't allow a nodelist; mpol_new() checks flags 2057 */ 2058 if (nodelist) 2059 goto out; 2060 mode = MPOL_PREFERRED; 2061 break; 2062 2063 /* 2064 * case MPOL_BIND: mpol_new() enforces non-empty nodemask. 2065 * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags. 2066 */ 2067 } 2068 2069 mode_flags = 0; 2070 if (flags) { 2071 /* 2072 * Currently, we only support two mutually exclusive 2073 * mode flags. 2074 */ 2075 if (!strcmp(flags, "static")) 2076 mode_flags |= MPOL_F_STATIC_NODES; 2077 else if (!strcmp(flags, "relative")) 2078 mode_flags |= MPOL_F_RELATIVE_NODES; 2079 else 2080 err = 1; 2081 } 2082 2083 new = mpol_new(mode, mode_flags, &nodes); 2084 if (IS_ERR(new)) 2085 err = 1; 2086 else if (no_context) 2087 new->w.user_nodemask = nodes; /* save for contextualization */ 2088 2089 out: 2090 /* Restore string for error message */ 2091 if (nodelist) 2092 *--nodelist = ':'; 2093 if (flags) 2094 *--flags = '='; 2095 if (!err) 2096 *mpol = new; 2097 return err; 2098 } 2099 #endif /* CONFIG_TMPFS */ 2100 2101 /** 2102 * mpol_to_str - format a mempolicy structure for printing 2103 * @buffer: to contain formatted mempolicy string 2104 * @maxlen: length of @buffer 2105 * @pol: pointer to mempolicy to be formatted 2106 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask 2107 * 2108 * Convert a mempolicy into a string. 2109 * Returns the number of characters in buffer (if positive) 2110 * or an error (negative) 2111 */ 2112 int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) 2113 { 2114 char *p = buffer; 2115 int l; 2116 nodemask_t nodes; 2117 unsigned short mode; 2118 unsigned short flags = pol ? pol->flags : 0; 2119 2120 /* 2121 * Sanity check: room for longest mode, flag and some nodes 2122 */ 2123 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); 2124 2125 if (!pol || pol == &default_policy) 2126 mode = MPOL_DEFAULT; 2127 else 2128 mode = pol->mode; 2129 2130 switch (mode) { 2131 case MPOL_DEFAULT: 2132 nodes_clear(nodes); 2133 break; 2134 2135 case MPOL_PREFERRED: 2136 nodes_clear(nodes); 2137 if (flags & MPOL_F_LOCAL) 2138 mode = MPOL_LOCAL; /* pseudo-policy */ 2139 else 2140 node_set(pol->v.preferred_node, nodes); 2141 break; 2142 2143 case MPOL_BIND: 2144 /* Fall through */ 2145 case MPOL_INTERLEAVE: 2146 if (no_context) 2147 nodes = pol->w.user_nodemask; 2148 else 2149 nodes = pol->v.nodes; 2150 break; 2151 2152 default: 2153 BUG(); 2154 } 2155 2156 l = strlen(policy_types[mode]); 2157 if (buffer + maxlen < p + l + 1) 2158 return -ENOSPC; 2159 2160 strcpy(p, policy_types[mode]); 2161 p += l; 2162 2163 if (flags & MPOL_MODE_FLAGS) { 2164 if (buffer + maxlen < p + 2) 2165 return -ENOSPC; 2166 *p++ = '='; 2167 2168 /* 2169 * Currently, the only defined flags are mutually exclusive 2170 */ 2171 if (flags & MPOL_F_STATIC_NODES) 2172 p += snprintf(p, buffer + maxlen - p, "static"); 2173 else if (flags & MPOL_F_RELATIVE_NODES) 2174 p += snprintf(p, buffer + maxlen - p, "relative"); 2175 } 2176 2177 if (!nodes_empty(nodes)) { 2178 if (buffer + maxlen < p + 2) 2179 return -ENOSPC; 2180 *p++ = ':'; 2181 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); 2182 } 2183 return p - buffer; 2184 } 2185 2186 struct numa_maps { 2187 unsigned long pages; 2188 unsigned long anon; 2189 unsigned long active; 2190 unsigned long writeback; 2191 unsigned long mapcount_max; 2192 unsigned long dirty; 2193 unsigned long swapcache; 2194 unsigned long node[MAX_NUMNODES]; 2195 }; 2196 2197 static void gather_stats(struct page *page, void *private, int pte_dirty) 2198 { 2199 struct numa_maps *md = private; 2200 int count = page_mapcount(page); 2201 2202 md->pages++; 2203 if (pte_dirty || PageDirty(page)) 2204 md->dirty++; 2205 2206 if (PageSwapCache(page)) 2207 md->swapcache++; 2208 2209 if (PageActive(page) || PageUnevictable(page)) 2210 md->active++; 2211 2212 if (PageWriteback(page)) 2213 md->writeback++; 2214 2215 if (PageAnon(page)) 2216 md->anon++; 2217 2218 if (count > md->mapcount_max) 2219 md->mapcount_max = count; 2220 2221 md->node[page_to_nid(page)]++; 2222 } 2223 2224 #ifdef CONFIG_HUGETLB_PAGE 2225 static void check_huge_range(struct vm_area_struct *vma, 2226 unsigned long start, unsigned long end, 2227 struct numa_maps *md) 2228 { 2229 unsigned long addr; 2230 struct page *page; 2231 struct hstate *h = hstate_vma(vma); 2232 unsigned long sz = huge_page_size(h); 2233 2234 for (addr = start; addr < end; addr += sz) { 2235 pte_t *ptep = huge_pte_offset(vma->vm_mm, 2236 addr & huge_page_mask(h)); 2237 pte_t pte; 2238 2239 if (!ptep) 2240 continue; 2241 2242 pte = *ptep; 2243 if (pte_none(pte)) 2244 continue; 2245 2246 page = pte_page(pte); 2247 if (!page) 2248 continue; 2249 2250 gather_stats(page, md, pte_dirty(*ptep)); 2251 } 2252 } 2253 #else 2254 static inline void check_huge_range(struct vm_area_struct *vma, 2255 unsigned long start, unsigned long end, 2256 struct numa_maps *md) 2257 { 2258 } 2259 #endif 2260 2261 /* 2262 * Display pages allocated per node and memory policy via /proc. 2263 */ 2264 int show_numa_map(struct seq_file *m, void *v) 2265 { 2266 struct proc_maps_private *priv = m->private; 2267 struct vm_area_struct *vma = v; 2268 struct numa_maps *md; 2269 struct file *file = vma->vm_file; 2270 struct mm_struct *mm = vma->vm_mm; 2271 struct mempolicy *pol; 2272 int n; 2273 char buffer[50]; 2274 2275 if (!mm) 2276 return 0; 2277 2278 md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL); 2279 if (!md) 2280 return 0; 2281 2282 pol = get_vma_policy(priv->task, vma, vma->vm_start); 2283 mpol_to_str(buffer, sizeof(buffer), pol, 0); 2284 mpol_cond_put(pol); 2285 2286 seq_printf(m, "%08lx %s", vma->vm_start, buffer); 2287 2288 if (file) { 2289 seq_printf(m, " file="); 2290 seq_path(m, &file->f_path, "\n\t= "); 2291 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { 2292 seq_printf(m, " heap"); 2293 } else if (vma->vm_start <= mm->start_stack && 2294 vma->vm_end >= mm->start_stack) { 2295 seq_printf(m, " stack"); 2296 } 2297 2298 if (is_vm_hugetlb_page(vma)) { 2299 check_huge_range(vma, vma->vm_start, vma->vm_end, md); 2300 seq_printf(m, " huge"); 2301 } else { 2302 check_pgd_range(vma, vma->vm_start, vma->vm_end, 2303 &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md); 2304 } 2305 2306 if (!md->pages) 2307 goto out; 2308 2309 if (md->anon) 2310 seq_printf(m," anon=%lu",md->anon); 2311 2312 if (md->dirty) 2313 seq_printf(m," dirty=%lu",md->dirty); 2314 2315 if (md->pages != md->anon && md->pages != md->dirty) 2316 seq_printf(m, " mapped=%lu", md->pages); 2317 2318 if (md->mapcount_max > 1) 2319 seq_printf(m, " mapmax=%lu", md->mapcount_max); 2320 2321 if (md->swapcache) 2322 seq_printf(m," swapcache=%lu", md->swapcache); 2323 2324 if (md->active < md->pages && !is_vm_hugetlb_page(vma)) 2325 seq_printf(m," active=%lu", md->active); 2326 2327 if (md->writeback) 2328 seq_printf(m," writeback=%lu", md->writeback); 2329 2330 for_each_node_state(n, N_HIGH_MEMORY) 2331 if (md->node[n]) 2332 seq_printf(m, " N%d=%lu", n, md->node[n]); 2333 out: 2334 seq_putc(m, '\n'); 2335 kfree(md); 2336 2337 if (m->count < m->size) 2338 m->version = (vma != priv->tail_vma) ? vma->vm_start : 0; 2339 return 0; 2340 } 2341