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 could replace all the switch()es with a mempolicy_ops structure. 67 */ 68 69 #include <linux/mempolicy.h> 70 #include <linux/mm.h> 71 #include <linux/highmem.h> 72 #include <linux/hugetlb.h> 73 #include <linux/kernel.h> 74 #include <linux/sched.h> 75 #include <linux/mm.h> 76 #include <linux/nodemask.h> 77 #include <linux/cpuset.h> 78 #include <linux/gfp.h> 79 #include <linux/slab.h> 80 #include <linux/string.h> 81 #include <linux/module.h> 82 #include <linux/interrupt.h> 83 #include <linux/init.h> 84 #include <linux/compat.h> 85 #include <linux/mempolicy.h> 86 #include <linux/swap.h> 87 #include <linux/seq_file.h> 88 #include <linux/proc_fs.h> 89 90 #include <asm/tlbflush.h> 91 #include <asm/uaccess.h> 92 93 /* Internal flags */ 94 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ 95 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ 96 #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */ 97 98 static kmem_cache_t *policy_cache; 99 static kmem_cache_t *sn_cache; 100 101 #define PDprintk(fmt...) 102 103 /* Highest zone. An specific allocation for a zone below that is not 104 policied. */ 105 int policy_zone = ZONE_DMA; 106 107 struct mempolicy default_policy = { 108 .refcnt = ATOMIC_INIT(1), /* never free it */ 109 .policy = MPOL_DEFAULT, 110 }; 111 112 /* Do sanity checking on a policy */ 113 static int mpol_check_policy(int mode, nodemask_t *nodes) 114 { 115 int empty = nodes_empty(*nodes); 116 117 switch (mode) { 118 case MPOL_DEFAULT: 119 if (!empty) 120 return -EINVAL; 121 break; 122 case MPOL_BIND: 123 case MPOL_INTERLEAVE: 124 /* Preferred will only use the first bit, but allow 125 more for now. */ 126 if (empty) 127 return -EINVAL; 128 break; 129 } 130 return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL; 131 } 132 /* Generate a custom zonelist for the BIND policy. */ 133 static struct zonelist *bind_zonelist(nodemask_t *nodes) 134 { 135 struct zonelist *zl; 136 int num, max, nd; 137 138 max = 1 + MAX_NR_ZONES * nodes_weight(*nodes); 139 zl = kmalloc(sizeof(void *) * max, GFP_KERNEL); 140 if (!zl) 141 return NULL; 142 num = 0; 143 for_each_node_mask(nd, *nodes) 144 zl->zones[num++] = &NODE_DATA(nd)->node_zones[policy_zone]; 145 zl->zones[num] = NULL; 146 return zl; 147 } 148 149 /* Create a new policy */ 150 static struct mempolicy *mpol_new(int mode, nodemask_t *nodes) 151 { 152 struct mempolicy *policy; 153 154 PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes_addr(*nodes)[0]); 155 if (mode == MPOL_DEFAULT) 156 return NULL; 157 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); 158 if (!policy) 159 return ERR_PTR(-ENOMEM); 160 atomic_set(&policy->refcnt, 1); 161 switch (mode) { 162 case MPOL_INTERLEAVE: 163 policy->v.nodes = *nodes; 164 if (nodes_weight(*nodes) == 0) { 165 kmem_cache_free(policy_cache, policy); 166 return ERR_PTR(-EINVAL); 167 } 168 break; 169 case MPOL_PREFERRED: 170 policy->v.preferred_node = first_node(*nodes); 171 if (policy->v.preferred_node >= MAX_NUMNODES) 172 policy->v.preferred_node = -1; 173 break; 174 case MPOL_BIND: 175 policy->v.zonelist = bind_zonelist(nodes); 176 if (policy->v.zonelist == NULL) { 177 kmem_cache_free(policy_cache, policy); 178 return ERR_PTR(-ENOMEM); 179 } 180 break; 181 } 182 policy->policy = mode; 183 policy->cpuset_mems_allowed = cpuset_mems_allowed(current); 184 return policy; 185 } 186 187 static void gather_stats(struct page *, void *); 188 static void migrate_page_add(struct vm_area_struct *vma, 189 struct page *page, struct list_head *pagelist, unsigned long flags); 190 191 /* Scan through pages checking if pages follow certain conditions. */ 192 static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 193 unsigned long addr, unsigned long end, 194 const nodemask_t *nodes, unsigned long flags, 195 void *private) 196 { 197 pte_t *orig_pte; 198 pte_t *pte; 199 spinlock_t *ptl; 200 201 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); 202 do { 203 struct page *page; 204 unsigned int nid; 205 206 if (!pte_present(*pte)) 207 continue; 208 page = vm_normal_page(vma, addr, *pte); 209 if (!page) 210 continue; 211 nid = page_to_nid(page); 212 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) 213 continue; 214 215 if (flags & MPOL_MF_STATS) 216 gather_stats(page, private); 217 else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { 218 spin_unlock(ptl); 219 migrate_page_add(vma, page, private, flags); 220 spin_lock(ptl); 221 } 222 else 223 break; 224 } while (pte++, addr += PAGE_SIZE, addr != end); 225 pte_unmap_unlock(orig_pte, ptl); 226 return addr != end; 227 } 228 229 static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, 230 unsigned long addr, unsigned long end, 231 const nodemask_t *nodes, unsigned long flags, 232 void *private) 233 { 234 pmd_t *pmd; 235 unsigned long next; 236 237 pmd = pmd_offset(pud, addr); 238 do { 239 next = pmd_addr_end(addr, end); 240 if (pmd_none_or_clear_bad(pmd)) 241 continue; 242 if (check_pte_range(vma, pmd, addr, next, nodes, 243 flags, private)) 244 return -EIO; 245 } while (pmd++, addr = next, addr != end); 246 return 0; 247 } 248 249 static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, 250 unsigned long addr, unsigned long end, 251 const nodemask_t *nodes, unsigned long flags, 252 void *private) 253 { 254 pud_t *pud; 255 unsigned long next; 256 257 pud = pud_offset(pgd, addr); 258 do { 259 next = pud_addr_end(addr, end); 260 if (pud_none_or_clear_bad(pud)) 261 continue; 262 if (check_pmd_range(vma, pud, addr, next, nodes, 263 flags, private)) 264 return -EIO; 265 } while (pud++, addr = next, addr != end); 266 return 0; 267 } 268 269 static inline int check_pgd_range(struct vm_area_struct *vma, 270 unsigned long addr, unsigned long end, 271 const nodemask_t *nodes, unsigned long flags, 272 void *private) 273 { 274 pgd_t *pgd; 275 unsigned long next; 276 277 pgd = pgd_offset(vma->vm_mm, addr); 278 do { 279 next = pgd_addr_end(addr, end); 280 if (pgd_none_or_clear_bad(pgd)) 281 continue; 282 if (check_pud_range(vma, pgd, addr, next, nodes, 283 flags, private)) 284 return -EIO; 285 } while (pgd++, addr = next, addr != end); 286 return 0; 287 } 288 289 /* Check if a vma is migratable */ 290 static inline int vma_migratable(struct vm_area_struct *vma) 291 { 292 if (vma->vm_flags & ( 293 VM_LOCKED|VM_IO|VM_HUGETLB|VM_PFNMAP)) 294 return 0; 295 return 1; 296 } 297 298 /* 299 * Check if all pages in a range are on a set of nodes. 300 * If pagelist != NULL then isolate pages from the LRU and 301 * put them on the pagelist. 302 */ 303 static struct vm_area_struct * 304 check_range(struct mm_struct *mm, unsigned long start, unsigned long end, 305 const nodemask_t *nodes, unsigned long flags, void *private) 306 { 307 int err; 308 struct vm_area_struct *first, *vma, *prev; 309 310 first = find_vma(mm, start); 311 if (!first) 312 return ERR_PTR(-EFAULT); 313 prev = NULL; 314 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { 315 if (!(flags & MPOL_MF_DISCONTIG_OK)) { 316 if (!vma->vm_next && vma->vm_end < end) 317 return ERR_PTR(-EFAULT); 318 if (prev && prev->vm_end < vma->vm_start) 319 return ERR_PTR(-EFAULT); 320 } 321 if (!is_vm_hugetlb_page(vma) && 322 ((flags & MPOL_MF_STRICT) || 323 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && 324 vma_migratable(vma)))) { 325 unsigned long endvma = vma->vm_end; 326 327 if (endvma > end) 328 endvma = end; 329 if (vma->vm_start > start) 330 start = vma->vm_start; 331 err = check_pgd_range(vma, start, endvma, nodes, 332 flags, private); 333 if (err) { 334 first = ERR_PTR(err); 335 break; 336 } 337 } 338 prev = vma; 339 } 340 return first; 341 } 342 343 /* Apply policy to a single VMA */ 344 static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) 345 { 346 int err = 0; 347 struct mempolicy *old = vma->vm_policy; 348 349 PDprintk("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", 350 vma->vm_start, vma->vm_end, vma->vm_pgoff, 351 vma->vm_ops, vma->vm_file, 352 vma->vm_ops ? vma->vm_ops->set_policy : NULL); 353 354 if (vma->vm_ops && vma->vm_ops->set_policy) 355 err = vma->vm_ops->set_policy(vma, new); 356 if (!err) { 357 mpol_get(new); 358 vma->vm_policy = new; 359 mpol_free(old); 360 } 361 return err; 362 } 363 364 /* Step 2: apply policy to a range and do splits. */ 365 static int mbind_range(struct vm_area_struct *vma, unsigned long start, 366 unsigned long end, struct mempolicy *new) 367 { 368 struct vm_area_struct *next; 369 int err; 370 371 err = 0; 372 for (; vma && vma->vm_start < end; vma = next) { 373 next = vma->vm_next; 374 if (vma->vm_start < start) 375 err = split_vma(vma->vm_mm, vma, start, 1); 376 if (!err && vma->vm_end > end) 377 err = split_vma(vma->vm_mm, vma, end, 0); 378 if (!err) 379 err = policy_vma(vma, new); 380 if (err) 381 break; 382 } 383 return err; 384 } 385 386 static int contextualize_policy(int mode, nodemask_t *nodes) 387 { 388 if (!nodes) 389 return 0; 390 391 cpuset_update_task_memory_state(); 392 if (!cpuset_nodes_subset_current_mems_allowed(*nodes)) 393 return -EINVAL; 394 return mpol_check_policy(mode, nodes); 395 } 396 397 /* Set the process memory policy */ 398 long do_set_mempolicy(int mode, nodemask_t *nodes) 399 { 400 struct mempolicy *new; 401 402 if (contextualize_policy(mode, nodes)) 403 return -EINVAL; 404 new = mpol_new(mode, nodes); 405 if (IS_ERR(new)) 406 return PTR_ERR(new); 407 mpol_free(current->mempolicy); 408 current->mempolicy = new; 409 if (new && new->policy == MPOL_INTERLEAVE) 410 current->il_next = first_node(new->v.nodes); 411 return 0; 412 } 413 414 /* Fill a zone bitmap for a policy */ 415 static void get_zonemask(struct mempolicy *p, nodemask_t *nodes) 416 { 417 int i; 418 419 nodes_clear(*nodes); 420 switch (p->policy) { 421 case MPOL_BIND: 422 for (i = 0; p->v.zonelist->zones[i]; i++) 423 node_set(p->v.zonelist->zones[i]->zone_pgdat->node_id, 424 *nodes); 425 break; 426 case MPOL_DEFAULT: 427 break; 428 case MPOL_INTERLEAVE: 429 *nodes = p->v.nodes; 430 break; 431 case MPOL_PREFERRED: 432 /* or use current node instead of online map? */ 433 if (p->v.preferred_node < 0) 434 *nodes = node_online_map; 435 else 436 node_set(p->v.preferred_node, *nodes); 437 break; 438 default: 439 BUG(); 440 } 441 } 442 443 static int lookup_node(struct mm_struct *mm, unsigned long addr) 444 { 445 struct page *p; 446 int err; 447 448 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); 449 if (err >= 0) { 450 err = page_to_nid(p); 451 put_page(p); 452 } 453 return err; 454 } 455 456 /* Retrieve NUMA policy */ 457 long do_get_mempolicy(int *policy, nodemask_t *nmask, 458 unsigned long addr, unsigned long flags) 459 { 460 int err; 461 struct mm_struct *mm = current->mm; 462 struct vm_area_struct *vma = NULL; 463 struct mempolicy *pol = current->mempolicy; 464 465 cpuset_update_task_memory_state(); 466 if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR)) 467 return -EINVAL; 468 if (flags & MPOL_F_ADDR) { 469 down_read(&mm->mmap_sem); 470 vma = find_vma_intersection(mm, addr, addr+1); 471 if (!vma) { 472 up_read(&mm->mmap_sem); 473 return -EFAULT; 474 } 475 if (vma->vm_ops && vma->vm_ops->get_policy) 476 pol = vma->vm_ops->get_policy(vma, addr); 477 else 478 pol = vma->vm_policy; 479 } else if (addr) 480 return -EINVAL; 481 482 if (!pol) 483 pol = &default_policy; 484 485 if (flags & MPOL_F_NODE) { 486 if (flags & MPOL_F_ADDR) { 487 err = lookup_node(mm, addr); 488 if (err < 0) 489 goto out; 490 *policy = err; 491 } else if (pol == current->mempolicy && 492 pol->policy == MPOL_INTERLEAVE) { 493 *policy = current->il_next; 494 } else { 495 err = -EINVAL; 496 goto out; 497 } 498 } else 499 *policy = pol->policy; 500 501 if (vma) { 502 up_read(¤t->mm->mmap_sem); 503 vma = NULL; 504 } 505 506 err = 0; 507 if (nmask) 508 get_zonemask(pol, nmask); 509 510 out: 511 if (vma) 512 up_read(¤t->mm->mmap_sem); 513 return err; 514 } 515 516 /* 517 * page migration 518 */ 519 520 /* Check if we are the only process mapping the page in question */ 521 static inline int single_mm_mapping(struct mm_struct *mm, 522 struct address_space *mapping) 523 { 524 struct vm_area_struct *vma; 525 struct prio_tree_iter iter; 526 int rc = 1; 527 528 spin_lock(&mapping->i_mmap_lock); 529 vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) 530 if (mm != vma->vm_mm) { 531 rc = 0; 532 goto out; 533 } 534 list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) 535 if (mm != vma->vm_mm) { 536 rc = 0; 537 goto out; 538 } 539 out: 540 spin_unlock(&mapping->i_mmap_lock); 541 return rc; 542 } 543 544 /* 545 * Add a page to be migrated to the pagelist 546 */ 547 static void migrate_page_add(struct vm_area_struct *vma, 548 struct page *page, struct list_head *pagelist, unsigned long flags) 549 { 550 /* 551 * Avoid migrating a page that is shared by others and not writable. 552 */ 553 if ((flags & MPOL_MF_MOVE_ALL) || !page->mapping || PageAnon(page) || 554 mapping_writably_mapped(page->mapping) || 555 single_mm_mapping(vma->vm_mm, page->mapping)) { 556 int rc = isolate_lru_page(page); 557 558 if (rc == 1) 559 list_add(&page->lru, pagelist); 560 /* 561 * If the isolate attempt was not successful then we just 562 * encountered an unswappable page. Something must be wrong. 563 */ 564 WARN_ON(rc == 0); 565 } 566 } 567 568 static int swap_pages(struct list_head *pagelist) 569 { 570 LIST_HEAD(moved); 571 LIST_HEAD(failed); 572 int n; 573 574 n = migrate_pages(pagelist, NULL, &moved, &failed); 575 putback_lru_pages(&failed); 576 putback_lru_pages(&moved); 577 578 return n; 579 } 580 581 /* 582 * For now migrate_pages simply swaps out the pages from nodes that are in 583 * the source set but not in the target set. In the future, we would 584 * want a function that moves pages between the two nodesets in such 585 * a way as to preserve the physical layout as much as possible. 586 * 587 * Returns the number of page that could not be moved. 588 */ 589 int do_migrate_pages(struct mm_struct *mm, 590 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) 591 { 592 LIST_HEAD(pagelist); 593 int count = 0; 594 nodemask_t nodes; 595 596 nodes_andnot(nodes, *from_nodes, *to_nodes); 597 598 down_read(&mm->mmap_sem); 599 check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nodes, 600 flags | MPOL_MF_DISCONTIG_OK, &pagelist); 601 602 if (!list_empty(&pagelist)) { 603 count = swap_pages(&pagelist); 604 putback_lru_pages(&pagelist); 605 } 606 607 up_read(&mm->mmap_sem); 608 return count; 609 } 610 611 long do_mbind(unsigned long start, unsigned long len, 612 unsigned long mode, nodemask_t *nmask, unsigned long flags) 613 { 614 struct vm_area_struct *vma; 615 struct mm_struct *mm = current->mm; 616 struct mempolicy *new; 617 unsigned long end; 618 int err; 619 LIST_HEAD(pagelist); 620 621 if ((flags & ~(unsigned long)(MPOL_MF_STRICT | 622 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) 623 || mode > MPOL_MAX) 624 return -EINVAL; 625 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_RESOURCE)) 626 return -EPERM; 627 628 if (start & ~PAGE_MASK) 629 return -EINVAL; 630 631 if (mode == MPOL_DEFAULT) 632 flags &= ~MPOL_MF_STRICT; 633 634 len = (len + PAGE_SIZE - 1) & PAGE_MASK; 635 end = start + len; 636 637 if (end < start) 638 return -EINVAL; 639 if (end == start) 640 return 0; 641 642 if (mpol_check_policy(mode, nmask)) 643 return -EINVAL; 644 645 new = mpol_new(mode, nmask); 646 if (IS_ERR(new)) 647 return PTR_ERR(new); 648 649 /* 650 * If we are using the default policy then operation 651 * on discontinuous address spaces is okay after all 652 */ 653 if (!new) 654 flags |= MPOL_MF_DISCONTIG_OK; 655 656 PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len, 657 mode,nodes_addr(nodes)[0]); 658 659 down_write(&mm->mmap_sem); 660 vma = check_range(mm, start, end, nmask, 661 flags | MPOL_MF_INVERT, &pagelist); 662 663 err = PTR_ERR(vma); 664 if (!IS_ERR(vma)) { 665 int nr_failed = 0; 666 667 err = mbind_range(vma, start, end, new); 668 if (!list_empty(&pagelist)) 669 nr_failed = swap_pages(&pagelist); 670 671 if (!err && nr_failed && (flags & MPOL_MF_STRICT)) 672 err = -EIO; 673 } 674 if (!list_empty(&pagelist)) 675 putback_lru_pages(&pagelist); 676 677 up_write(&mm->mmap_sem); 678 mpol_free(new); 679 return err; 680 } 681 682 /* 683 * User space interface with variable sized bitmaps for nodelists. 684 */ 685 686 /* Copy a node mask from user space. */ 687 static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, 688 unsigned long maxnode) 689 { 690 unsigned long k; 691 unsigned long nlongs; 692 unsigned long endmask; 693 694 --maxnode; 695 nodes_clear(*nodes); 696 if (maxnode == 0 || !nmask) 697 return 0; 698 699 nlongs = BITS_TO_LONGS(maxnode); 700 if ((maxnode % BITS_PER_LONG) == 0) 701 endmask = ~0UL; 702 else 703 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; 704 705 /* When the user specified more nodes than supported just check 706 if the non supported part is all zero. */ 707 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { 708 if (nlongs > PAGE_SIZE/sizeof(long)) 709 return -EINVAL; 710 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { 711 unsigned long t; 712 if (get_user(t, nmask + k)) 713 return -EFAULT; 714 if (k == nlongs - 1) { 715 if (t & endmask) 716 return -EINVAL; 717 } else if (t) 718 return -EINVAL; 719 } 720 nlongs = BITS_TO_LONGS(MAX_NUMNODES); 721 endmask = ~0UL; 722 } 723 724 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) 725 return -EFAULT; 726 nodes_addr(*nodes)[nlongs-1] &= endmask; 727 return 0; 728 } 729 730 /* Copy a kernel node mask to user space */ 731 static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, 732 nodemask_t *nodes) 733 { 734 unsigned long copy = ALIGN(maxnode-1, 64) / 8; 735 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); 736 737 if (copy > nbytes) { 738 if (copy > PAGE_SIZE) 739 return -EINVAL; 740 if (clear_user((char __user *)mask + nbytes, copy - nbytes)) 741 return -EFAULT; 742 copy = nbytes; 743 } 744 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; 745 } 746 747 asmlinkage long sys_mbind(unsigned long start, unsigned long len, 748 unsigned long mode, 749 unsigned long __user *nmask, unsigned long maxnode, 750 unsigned flags) 751 { 752 nodemask_t nodes; 753 int err; 754 755 err = get_nodes(&nodes, nmask, maxnode); 756 if (err) 757 return err; 758 return do_mbind(start, len, mode, &nodes, flags); 759 } 760 761 /* Set the process memory policy */ 762 asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, 763 unsigned long maxnode) 764 { 765 int err; 766 nodemask_t nodes; 767 768 if (mode < 0 || mode > MPOL_MAX) 769 return -EINVAL; 770 err = get_nodes(&nodes, nmask, maxnode); 771 if (err) 772 return err; 773 return do_set_mempolicy(mode, &nodes); 774 } 775 776 asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, 777 const unsigned long __user *old_nodes, 778 const unsigned long __user *new_nodes) 779 { 780 struct mm_struct *mm; 781 struct task_struct *task; 782 nodemask_t old; 783 nodemask_t new; 784 nodemask_t task_nodes; 785 int err; 786 787 err = get_nodes(&old, old_nodes, maxnode); 788 if (err) 789 return err; 790 791 err = get_nodes(&new, new_nodes, maxnode); 792 if (err) 793 return err; 794 795 /* Find the mm_struct */ 796 read_lock(&tasklist_lock); 797 task = pid ? find_task_by_pid(pid) : current; 798 if (!task) { 799 read_unlock(&tasklist_lock); 800 return -ESRCH; 801 } 802 mm = get_task_mm(task); 803 read_unlock(&tasklist_lock); 804 805 if (!mm) 806 return -EINVAL; 807 808 /* 809 * Check if this process has the right to modify the specified 810 * process. The right exists if the process has administrative 811 * capabilities, superuser priviledges or the same 812 * userid as the target process. 813 */ 814 if ((current->euid != task->suid) && (current->euid != task->uid) && 815 (current->uid != task->suid) && (current->uid != task->uid) && 816 !capable(CAP_SYS_ADMIN)) { 817 err = -EPERM; 818 goto out; 819 } 820 821 task_nodes = cpuset_mems_allowed(task); 822 /* Is the user allowed to access the target nodes? */ 823 if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_ADMIN)) { 824 err = -EPERM; 825 goto out; 826 } 827 828 err = do_migrate_pages(mm, &old, &new, MPOL_MF_MOVE); 829 out: 830 mmput(mm); 831 return err; 832 } 833 834 835 /* Retrieve NUMA policy */ 836 asmlinkage long sys_get_mempolicy(int __user *policy, 837 unsigned long __user *nmask, 838 unsigned long maxnode, 839 unsigned long addr, unsigned long flags) 840 { 841 int err, pval; 842 nodemask_t nodes; 843 844 if (nmask != NULL && maxnode < MAX_NUMNODES) 845 return -EINVAL; 846 847 err = do_get_mempolicy(&pval, &nodes, addr, flags); 848 849 if (err) 850 return err; 851 852 if (policy && put_user(pval, policy)) 853 return -EFAULT; 854 855 if (nmask) 856 err = copy_nodes_to_user(nmask, maxnode, &nodes); 857 858 return err; 859 } 860 861 #ifdef CONFIG_COMPAT 862 863 asmlinkage long compat_sys_get_mempolicy(int __user *policy, 864 compat_ulong_t __user *nmask, 865 compat_ulong_t maxnode, 866 compat_ulong_t addr, compat_ulong_t flags) 867 { 868 long err; 869 unsigned long __user *nm = NULL; 870 unsigned long nr_bits, alloc_size; 871 DECLARE_BITMAP(bm, MAX_NUMNODES); 872 873 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 874 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 875 876 if (nmask) 877 nm = compat_alloc_user_space(alloc_size); 878 879 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); 880 881 if (!err && nmask) { 882 err = copy_from_user(bm, nm, alloc_size); 883 /* ensure entire bitmap is zeroed */ 884 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); 885 err |= compat_put_bitmap(nmask, bm, nr_bits); 886 } 887 888 return err; 889 } 890 891 asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, 892 compat_ulong_t maxnode) 893 { 894 long err = 0; 895 unsigned long __user *nm = NULL; 896 unsigned long nr_bits, alloc_size; 897 DECLARE_BITMAP(bm, MAX_NUMNODES); 898 899 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 900 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 901 902 if (nmask) { 903 err = compat_get_bitmap(bm, nmask, nr_bits); 904 nm = compat_alloc_user_space(alloc_size); 905 err |= copy_to_user(nm, bm, alloc_size); 906 } 907 908 if (err) 909 return -EFAULT; 910 911 return sys_set_mempolicy(mode, nm, nr_bits+1); 912 } 913 914 asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, 915 compat_ulong_t mode, compat_ulong_t __user *nmask, 916 compat_ulong_t maxnode, compat_ulong_t flags) 917 { 918 long err = 0; 919 unsigned long __user *nm = NULL; 920 unsigned long nr_bits, alloc_size; 921 nodemask_t bm; 922 923 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); 924 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; 925 926 if (nmask) { 927 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); 928 nm = compat_alloc_user_space(alloc_size); 929 err |= copy_to_user(nm, nodes_addr(bm), alloc_size); 930 } 931 932 if (err) 933 return -EFAULT; 934 935 return sys_mbind(start, len, mode, nm, nr_bits+1, flags); 936 } 937 938 #endif 939 940 /* Return effective policy for a VMA */ 941 static struct mempolicy * get_vma_policy(struct task_struct *task, 942 struct vm_area_struct *vma, unsigned long addr) 943 { 944 struct mempolicy *pol = task->mempolicy; 945 946 if (vma) { 947 if (vma->vm_ops && vma->vm_ops->get_policy) 948 pol = vma->vm_ops->get_policy(vma, addr); 949 else if (vma->vm_policy && 950 vma->vm_policy->policy != MPOL_DEFAULT) 951 pol = vma->vm_policy; 952 } 953 if (!pol) 954 pol = &default_policy; 955 return pol; 956 } 957 958 /* Return a zonelist representing a mempolicy */ 959 static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy) 960 { 961 int nd; 962 963 switch (policy->policy) { 964 case MPOL_PREFERRED: 965 nd = policy->v.preferred_node; 966 if (nd < 0) 967 nd = numa_node_id(); 968 break; 969 case MPOL_BIND: 970 /* Lower zones don't get a policy applied */ 971 /* Careful: current->mems_allowed might have moved */ 972 if (gfp_zone(gfp) >= policy_zone) 973 if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist)) 974 return policy->v.zonelist; 975 /*FALL THROUGH*/ 976 case MPOL_INTERLEAVE: /* should not happen */ 977 case MPOL_DEFAULT: 978 nd = numa_node_id(); 979 break; 980 default: 981 nd = 0; 982 BUG(); 983 } 984 return NODE_DATA(nd)->node_zonelists + gfp_zone(gfp); 985 } 986 987 /* Do dynamic interleaving for a process */ 988 static unsigned interleave_nodes(struct mempolicy *policy) 989 { 990 unsigned nid, next; 991 struct task_struct *me = current; 992 993 nid = me->il_next; 994 next = next_node(nid, policy->v.nodes); 995 if (next >= MAX_NUMNODES) 996 next = first_node(policy->v.nodes); 997 me->il_next = next; 998 return nid; 999 } 1000 1001 /* Do static interleaving for a VMA with known offset. */ 1002 static unsigned offset_il_node(struct mempolicy *pol, 1003 struct vm_area_struct *vma, unsigned long off) 1004 { 1005 unsigned nnodes = nodes_weight(pol->v.nodes); 1006 unsigned target = (unsigned)off % nnodes; 1007 int c; 1008 int nid = -1; 1009 1010 c = 0; 1011 do { 1012 nid = next_node(nid, pol->v.nodes); 1013 c++; 1014 } while (c <= target); 1015 return nid; 1016 } 1017 1018 /* Determine a node number for interleave */ 1019 static inline unsigned interleave_nid(struct mempolicy *pol, 1020 struct vm_area_struct *vma, unsigned long addr, int shift) 1021 { 1022 if (vma) { 1023 unsigned long off; 1024 1025 off = vma->vm_pgoff; 1026 off += (addr - vma->vm_start) >> shift; 1027 return offset_il_node(pol, vma, off); 1028 } else 1029 return interleave_nodes(pol); 1030 } 1031 1032 /* Return a zonelist suitable for a huge page allocation. */ 1033 struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr) 1034 { 1035 struct mempolicy *pol = get_vma_policy(current, vma, addr); 1036 1037 if (pol->policy == MPOL_INTERLEAVE) { 1038 unsigned nid; 1039 1040 nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT); 1041 return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER); 1042 } 1043 return zonelist_policy(GFP_HIGHUSER, pol); 1044 } 1045 1046 /* Allocate a page in interleaved policy. 1047 Own path because it needs to do special accounting. */ 1048 static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, 1049 unsigned nid) 1050 { 1051 struct zonelist *zl; 1052 struct page *page; 1053 1054 zl = NODE_DATA(nid)->node_zonelists + gfp_zone(gfp); 1055 page = __alloc_pages(gfp, order, zl); 1056 if (page && page_zone(page) == zl->zones[0]) { 1057 zone_pcp(zl->zones[0],get_cpu())->interleave_hit++; 1058 put_cpu(); 1059 } 1060 return page; 1061 } 1062 1063 /** 1064 * alloc_page_vma - Allocate a page for a VMA. 1065 * 1066 * @gfp: 1067 * %GFP_USER user allocation. 1068 * %GFP_KERNEL kernel allocations, 1069 * %GFP_HIGHMEM highmem/user allocations, 1070 * %GFP_FS allocation should not call back into a file system. 1071 * %GFP_ATOMIC don't sleep. 1072 * 1073 * @vma: Pointer to VMA or NULL if not available. 1074 * @addr: Virtual Address of the allocation. Must be inside the VMA. 1075 * 1076 * This function allocates a page from the kernel page pool and applies 1077 * a NUMA policy associated with the VMA or the current process. 1078 * When VMA is not NULL caller must hold down_read on the mmap_sem of the 1079 * mm_struct of the VMA to prevent it from going away. Should be used for 1080 * all allocations for pages that will be mapped into 1081 * user space. Returns NULL when no page can be allocated. 1082 * 1083 * Should be called with the mm_sem of the vma hold. 1084 */ 1085 struct page * 1086 alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) 1087 { 1088 struct mempolicy *pol = get_vma_policy(current, vma, addr); 1089 1090 cpuset_update_task_memory_state(); 1091 1092 if (unlikely(pol->policy == MPOL_INTERLEAVE)) { 1093 unsigned nid; 1094 1095 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT); 1096 return alloc_page_interleave(gfp, 0, nid); 1097 } 1098 return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol)); 1099 } 1100 1101 /** 1102 * alloc_pages_current - Allocate pages. 1103 * 1104 * @gfp: 1105 * %GFP_USER user allocation, 1106 * %GFP_KERNEL kernel allocation, 1107 * %GFP_HIGHMEM highmem allocation, 1108 * %GFP_FS don't call back into a file system. 1109 * %GFP_ATOMIC don't sleep. 1110 * @order: Power of two of allocation size in pages. 0 is a single page. 1111 * 1112 * Allocate a page from the kernel page pool. When not in 1113 * interrupt context and apply the current process NUMA policy. 1114 * Returns NULL when no page can be allocated. 1115 * 1116 * Don't call cpuset_update_task_memory_state() unless 1117 * 1) it's ok to take cpuset_sem (can WAIT), and 1118 * 2) allocating for current task (not interrupt). 1119 */ 1120 struct page *alloc_pages_current(gfp_t gfp, unsigned order) 1121 { 1122 struct mempolicy *pol = current->mempolicy; 1123 1124 if ((gfp & __GFP_WAIT) && !in_interrupt()) 1125 cpuset_update_task_memory_state(); 1126 if (!pol || in_interrupt()) 1127 pol = &default_policy; 1128 if (pol->policy == MPOL_INTERLEAVE) 1129 return alloc_page_interleave(gfp, order, interleave_nodes(pol)); 1130 return __alloc_pages(gfp, order, zonelist_policy(gfp, pol)); 1131 } 1132 EXPORT_SYMBOL(alloc_pages_current); 1133 1134 /* 1135 * If mpol_copy() sees current->cpuset == cpuset_being_rebound, then it 1136 * rebinds the mempolicy its copying by calling mpol_rebind_policy() 1137 * with the mems_allowed returned by cpuset_mems_allowed(). This 1138 * keeps mempolicies cpuset relative after its cpuset moves. See 1139 * further kernel/cpuset.c update_nodemask(). 1140 */ 1141 void *cpuset_being_rebound; 1142 1143 /* Slow path of a mempolicy copy */ 1144 struct mempolicy *__mpol_copy(struct mempolicy *old) 1145 { 1146 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); 1147 1148 if (!new) 1149 return ERR_PTR(-ENOMEM); 1150 if (current_cpuset_is_being_rebound()) { 1151 nodemask_t mems = cpuset_mems_allowed(current); 1152 mpol_rebind_policy(old, &mems); 1153 } 1154 *new = *old; 1155 atomic_set(&new->refcnt, 1); 1156 if (new->policy == MPOL_BIND) { 1157 int sz = ksize(old->v.zonelist); 1158 new->v.zonelist = kmalloc(sz, SLAB_KERNEL); 1159 if (!new->v.zonelist) { 1160 kmem_cache_free(policy_cache, new); 1161 return ERR_PTR(-ENOMEM); 1162 } 1163 memcpy(new->v.zonelist, old->v.zonelist, sz); 1164 } 1165 return new; 1166 } 1167 1168 /* Slow path of a mempolicy comparison */ 1169 int __mpol_equal(struct mempolicy *a, struct mempolicy *b) 1170 { 1171 if (!a || !b) 1172 return 0; 1173 if (a->policy != b->policy) 1174 return 0; 1175 switch (a->policy) { 1176 case MPOL_DEFAULT: 1177 return 1; 1178 case MPOL_INTERLEAVE: 1179 return nodes_equal(a->v.nodes, b->v.nodes); 1180 case MPOL_PREFERRED: 1181 return a->v.preferred_node == b->v.preferred_node; 1182 case MPOL_BIND: { 1183 int i; 1184 for (i = 0; a->v.zonelist->zones[i]; i++) 1185 if (a->v.zonelist->zones[i] != b->v.zonelist->zones[i]) 1186 return 0; 1187 return b->v.zonelist->zones[i] == NULL; 1188 } 1189 default: 1190 BUG(); 1191 return 0; 1192 } 1193 } 1194 1195 /* Slow path of a mpol destructor. */ 1196 void __mpol_free(struct mempolicy *p) 1197 { 1198 if (!atomic_dec_and_test(&p->refcnt)) 1199 return; 1200 if (p->policy == MPOL_BIND) 1201 kfree(p->v.zonelist); 1202 p->policy = MPOL_DEFAULT; 1203 kmem_cache_free(policy_cache, p); 1204 } 1205 1206 /* 1207 * Shared memory backing store policy support. 1208 * 1209 * Remember policies even when nobody has shared memory mapped. 1210 * The policies are kept in Red-Black tree linked from the inode. 1211 * They are protected by the sp->lock spinlock, which should be held 1212 * for any accesses to the tree. 1213 */ 1214 1215 /* lookup first element intersecting start-end */ 1216 /* Caller holds sp->lock */ 1217 static struct sp_node * 1218 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) 1219 { 1220 struct rb_node *n = sp->root.rb_node; 1221 1222 while (n) { 1223 struct sp_node *p = rb_entry(n, struct sp_node, nd); 1224 1225 if (start >= p->end) 1226 n = n->rb_right; 1227 else if (end <= p->start) 1228 n = n->rb_left; 1229 else 1230 break; 1231 } 1232 if (!n) 1233 return NULL; 1234 for (;;) { 1235 struct sp_node *w = NULL; 1236 struct rb_node *prev = rb_prev(n); 1237 if (!prev) 1238 break; 1239 w = rb_entry(prev, struct sp_node, nd); 1240 if (w->end <= start) 1241 break; 1242 n = prev; 1243 } 1244 return rb_entry(n, struct sp_node, nd); 1245 } 1246 1247 /* Insert a new shared policy into the list. */ 1248 /* Caller holds sp->lock */ 1249 static void sp_insert(struct shared_policy *sp, struct sp_node *new) 1250 { 1251 struct rb_node **p = &sp->root.rb_node; 1252 struct rb_node *parent = NULL; 1253 struct sp_node *nd; 1254 1255 while (*p) { 1256 parent = *p; 1257 nd = rb_entry(parent, struct sp_node, nd); 1258 if (new->start < nd->start) 1259 p = &(*p)->rb_left; 1260 else if (new->end > nd->end) 1261 p = &(*p)->rb_right; 1262 else 1263 BUG(); 1264 } 1265 rb_link_node(&new->nd, parent, p); 1266 rb_insert_color(&new->nd, &sp->root); 1267 PDprintk("inserting %lx-%lx: %d\n", new->start, new->end, 1268 new->policy ? new->policy->policy : 0); 1269 } 1270 1271 /* Find shared policy intersecting idx */ 1272 struct mempolicy * 1273 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) 1274 { 1275 struct mempolicy *pol = NULL; 1276 struct sp_node *sn; 1277 1278 if (!sp->root.rb_node) 1279 return NULL; 1280 spin_lock(&sp->lock); 1281 sn = sp_lookup(sp, idx, idx+1); 1282 if (sn) { 1283 mpol_get(sn->policy); 1284 pol = sn->policy; 1285 } 1286 spin_unlock(&sp->lock); 1287 return pol; 1288 } 1289 1290 static void sp_delete(struct shared_policy *sp, struct sp_node *n) 1291 { 1292 PDprintk("deleting %lx-l%x\n", n->start, n->end); 1293 rb_erase(&n->nd, &sp->root); 1294 mpol_free(n->policy); 1295 kmem_cache_free(sn_cache, n); 1296 } 1297 1298 struct sp_node * 1299 sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol) 1300 { 1301 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL); 1302 1303 if (!n) 1304 return NULL; 1305 n->start = start; 1306 n->end = end; 1307 mpol_get(pol); 1308 n->policy = pol; 1309 return n; 1310 } 1311 1312 /* Replace a policy range. */ 1313 static int shared_policy_replace(struct shared_policy *sp, unsigned long start, 1314 unsigned long end, struct sp_node *new) 1315 { 1316 struct sp_node *n, *new2 = NULL; 1317 1318 restart: 1319 spin_lock(&sp->lock); 1320 n = sp_lookup(sp, start, end); 1321 /* Take care of old policies in the same range. */ 1322 while (n && n->start < end) { 1323 struct rb_node *next = rb_next(&n->nd); 1324 if (n->start >= start) { 1325 if (n->end <= end) 1326 sp_delete(sp, n); 1327 else 1328 n->start = end; 1329 } else { 1330 /* Old policy spanning whole new range. */ 1331 if (n->end > end) { 1332 if (!new2) { 1333 spin_unlock(&sp->lock); 1334 new2 = sp_alloc(end, n->end, n->policy); 1335 if (!new2) 1336 return -ENOMEM; 1337 goto restart; 1338 } 1339 n->end = start; 1340 sp_insert(sp, new2); 1341 new2 = NULL; 1342 break; 1343 } else 1344 n->end = start; 1345 } 1346 if (!next) 1347 break; 1348 n = rb_entry(next, struct sp_node, nd); 1349 } 1350 if (new) 1351 sp_insert(sp, new); 1352 spin_unlock(&sp->lock); 1353 if (new2) { 1354 mpol_free(new2->policy); 1355 kmem_cache_free(sn_cache, new2); 1356 } 1357 return 0; 1358 } 1359 1360 int mpol_set_shared_policy(struct shared_policy *info, 1361 struct vm_area_struct *vma, struct mempolicy *npol) 1362 { 1363 int err; 1364 struct sp_node *new = NULL; 1365 unsigned long sz = vma_pages(vma); 1366 1367 PDprintk("set_shared_policy %lx sz %lu %d %lx\n", 1368 vma->vm_pgoff, 1369 sz, npol? npol->policy : -1, 1370 npol ? nodes_addr(npol->v.nodes)[0] : -1); 1371 1372 if (npol) { 1373 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); 1374 if (!new) 1375 return -ENOMEM; 1376 } 1377 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); 1378 if (err && new) 1379 kmem_cache_free(sn_cache, new); 1380 return err; 1381 } 1382 1383 /* Free a backing policy store on inode delete. */ 1384 void mpol_free_shared_policy(struct shared_policy *p) 1385 { 1386 struct sp_node *n; 1387 struct rb_node *next; 1388 1389 if (!p->root.rb_node) 1390 return; 1391 spin_lock(&p->lock); 1392 next = rb_first(&p->root); 1393 while (next) { 1394 n = rb_entry(next, struct sp_node, nd); 1395 next = rb_next(&n->nd); 1396 rb_erase(&n->nd, &p->root); 1397 mpol_free(n->policy); 1398 kmem_cache_free(sn_cache, n); 1399 } 1400 spin_unlock(&p->lock); 1401 } 1402 1403 /* assumes fs == KERNEL_DS */ 1404 void __init numa_policy_init(void) 1405 { 1406 policy_cache = kmem_cache_create("numa_policy", 1407 sizeof(struct mempolicy), 1408 0, SLAB_PANIC, NULL, NULL); 1409 1410 sn_cache = kmem_cache_create("shared_policy_node", 1411 sizeof(struct sp_node), 1412 0, SLAB_PANIC, NULL, NULL); 1413 1414 /* Set interleaving policy for system init. This way not all 1415 the data structures allocated at system boot end up in node zero. */ 1416 1417 if (do_set_mempolicy(MPOL_INTERLEAVE, &node_online_map)) 1418 printk("numa_policy_init: interleaving failed\n"); 1419 } 1420 1421 /* Reset policy of current process to default */ 1422 void numa_default_policy(void) 1423 { 1424 do_set_mempolicy(MPOL_DEFAULT, NULL); 1425 } 1426 1427 /* Migrate a policy to a different set of nodes */ 1428 void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask) 1429 { 1430 nodemask_t *mpolmask; 1431 nodemask_t tmp; 1432 1433 if (!pol) 1434 return; 1435 mpolmask = &pol->cpuset_mems_allowed; 1436 if (nodes_equal(*mpolmask, *newmask)) 1437 return; 1438 1439 switch (pol->policy) { 1440 case MPOL_DEFAULT: 1441 break; 1442 case MPOL_INTERLEAVE: 1443 nodes_remap(tmp, pol->v.nodes, *mpolmask, *newmask); 1444 pol->v.nodes = tmp; 1445 *mpolmask = *newmask; 1446 current->il_next = node_remap(current->il_next, 1447 *mpolmask, *newmask); 1448 break; 1449 case MPOL_PREFERRED: 1450 pol->v.preferred_node = node_remap(pol->v.preferred_node, 1451 *mpolmask, *newmask); 1452 *mpolmask = *newmask; 1453 break; 1454 case MPOL_BIND: { 1455 nodemask_t nodes; 1456 struct zone **z; 1457 struct zonelist *zonelist; 1458 1459 nodes_clear(nodes); 1460 for (z = pol->v.zonelist->zones; *z; z++) 1461 node_set((*z)->zone_pgdat->node_id, nodes); 1462 nodes_remap(tmp, nodes, *mpolmask, *newmask); 1463 nodes = tmp; 1464 1465 zonelist = bind_zonelist(&nodes); 1466 1467 /* If no mem, then zonelist is NULL and we keep old zonelist. 1468 * If that old zonelist has no remaining mems_allowed nodes, 1469 * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT. 1470 */ 1471 1472 if (zonelist) { 1473 /* Good - got mem - substitute new zonelist */ 1474 kfree(pol->v.zonelist); 1475 pol->v.zonelist = zonelist; 1476 } 1477 *mpolmask = *newmask; 1478 break; 1479 } 1480 default: 1481 BUG(); 1482 break; 1483 } 1484 } 1485 1486 /* 1487 * Wrapper for mpol_rebind_policy() that just requires task 1488 * pointer, and updates task mempolicy. 1489 */ 1490 1491 void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) 1492 { 1493 mpol_rebind_policy(tsk->mempolicy, new); 1494 } 1495 1496 /* 1497 * Rebind each vma in mm to new nodemask. 1498 * 1499 * Call holding a reference to mm. Takes mm->mmap_sem during call. 1500 */ 1501 1502 void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) 1503 { 1504 struct vm_area_struct *vma; 1505 1506 down_write(&mm->mmap_sem); 1507 for (vma = mm->mmap; vma; vma = vma->vm_next) 1508 mpol_rebind_policy(vma->vm_policy, new); 1509 up_write(&mm->mmap_sem); 1510 } 1511 1512 /* 1513 * Display pages allocated per node and memory policy via /proc. 1514 */ 1515 1516 static const char *policy_types[] = { "default", "prefer", "bind", 1517 "interleave" }; 1518 1519 /* 1520 * Convert a mempolicy into a string. 1521 * Returns the number of characters in buffer (if positive) 1522 * or an error (negative) 1523 */ 1524 static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) 1525 { 1526 char *p = buffer; 1527 int l; 1528 nodemask_t nodes; 1529 int mode = pol ? pol->policy : MPOL_DEFAULT; 1530 1531 switch (mode) { 1532 case MPOL_DEFAULT: 1533 nodes_clear(nodes); 1534 break; 1535 1536 case MPOL_PREFERRED: 1537 nodes_clear(nodes); 1538 node_set(pol->v.preferred_node, nodes); 1539 break; 1540 1541 case MPOL_BIND: 1542 get_zonemask(pol, &nodes); 1543 break; 1544 1545 case MPOL_INTERLEAVE: 1546 nodes = pol->v.nodes; 1547 break; 1548 1549 default: 1550 BUG(); 1551 return -EFAULT; 1552 } 1553 1554 l = strlen(policy_types[mode]); 1555 if (buffer + maxlen < p + l + 1) 1556 return -ENOSPC; 1557 1558 strcpy(p, policy_types[mode]); 1559 p += l; 1560 1561 if (!nodes_empty(nodes)) { 1562 if (buffer + maxlen < p + 2) 1563 return -ENOSPC; 1564 *p++ = '='; 1565 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); 1566 } 1567 return p - buffer; 1568 } 1569 1570 struct numa_maps { 1571 unsigned long pages; 1572 unsigned long anon; 1573 unsigned long mapped; 1574 unsigned long mapcount_max; 1575 unsigned long node[MAX_NUMNODES]; 1576 }; 1577 1578 static void gather_stats(struct page *page, void *private) 1579 { 1580 struct numa_maps *md = private; 1581 int count = page_mapcount(page); 1582 1583 if (count) 1584 md->mapped++; 1585 1586 if (count > md->mapcount_max) 1587 md->mapcount_max = count; 1588 1589 md->pages++; 1590 1591 if (PageAnon(page)) 1592 md->anon++; 1593 1594 md->node[page_to_nid(page)]++; 1595 cond_resched(); 1596 } 1597 1598 int show_numa_map(struct seq_file *m, void *v) 1599 { 1600 struct task_struct *task = m->private; 1601 struct vm_area_struct *vma = v; 1602 struct numa_maps *md; 1603 int n; 1604 char buffer[50]; 1605 1606 if (!vma->vm_mm) 1607 return 0; 1608 1609 md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL); 1610 if (!md) 1611 return 0; 1612 1613 check_pgd_range(vma, vma->vm_start, vma->vm_end, 1614 &node_online_map, MPOL_MF_STATS, md); 1615 1616 if (md->pages) { 1617 mpol_to_str(buffer, sizeof(buffer), 1618 get_vma_policy(task, vma, vma->vm_start)); 1619 1620 seq_printf(m, "%08lx %s pages=%lu mapped=%lu maxref=%lu", 1621 vma->vm_start, buffer, md->pages, 1622 md->mapped, md->mapcount_max); 1623 1624 if (md->anon) 1625 seq_printf(m," anon=%lu",md->anon); 1626 1627 for_each_online_node(n) 1628 if (md->node[n]) 1629 seq_printf(m, " N%d=%lu", n, md->node[n]); 1630 1631 seq_putc(m, '\n'); 1632 } 1633 kfree(md); 1634 1635 if (m->count < m->size) 1636 m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0; 1637 return 0; 1638 } 1639 1640