1 /* 2 * linux/mm/vmstat.c 3 * 4 * Manages VM statistics 5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 6 * 7 * zoned VM statistics 8 * Copyright (C) 2006 Silicon Graphics, Inc., 9 * Christoph Lameter <christoph@lameter.com> 10 */ 11 12 #include <linux/mm.h> 13 #include <linux/err.h> 14 #include <linux/module.h> 15 #include <linux/cpu.h> 16 #include <linux/sched.h> 17 18 #ifdef CONFIG_VM_EVENT_COUNTERS 19 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; 20 EXPORT_PER_CPU_SYMBOL(vm_event_states); 21 22 static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask) 23 { 24 int cpu; 25 int i; 26 27 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); 28 29 for_each_cpu_mask(cpu, *cpumask) { 30 struct vm_event_state *this = &per_cpu(vm_event_states, cpu); 31 32 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) 33 ret[i] += this->event[i]; 34 } 35 } 36 37 /* 38 * Accumulate the vm event counters across all CPUs. 39 * The result is unavoidably approximate - it can change 40 * during and after execution of this function. 41 */ 42 void all_vm_events(unsigned long *ret) 43 { 44 get_online_cpus(); 45 sum_vm_events(ret, &cpu_online_map); 46 put_online_cpus(); 47 } 48 EXPORT_SYMBOL_GPL(all_vm_events); 49 50 #ifdef CONFIG_HOTPLUG 51 /* 52 * Fold the foreign cpu events into our own. 53 * 54 * This is adding to the events on one processor 55 * but keeps the global counts constant. 56 */ 57 void vm_events_fold_cpu(int cpu) 58 { 59 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu); 60 int i; 61 62 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { 63 count_vm_events(i, fold_state->event[i]); 64 fold_state->event[i] = 0; 65 } 66 } 67 #endif /* CONFIG_HOTPLUG */ 68 69 #endif /* CONFIG_VM_EVENT_COUNTERS */ 70 71 /* 72 * Manage combined zone based / global counters 73 * 74 * vm_stat contains the global counters 75 */ 76 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 77 EXPORT_SYMBOL(vm_stat); 78 79 #ifdef CONFIG_SMP 80 81 static int calculate_threshold(struct zone *zone) 82 { 83 int threshold; 84 int mem; /* memory in 128 MB units */ 85 86 /* 87 * The threshold scales with the number of processors and the amount 88 * of memory per zone. More memory means that we can defer updates for 89 * longer, more processors could lead to more contention. 90 * fls() is used to have a cheap way of logarithmic scaling. 91 * 92 * Some sample thresholds: 93 * 94 * Threshold Processors (fls) Zonesize fls(mem+1) 95 * ------------------------------------------------------------------ 96 * 8 1 1 0.9-1 GB 4 97 * 16 2 2 0.9-1 GB 4 98 * 20 2 2 1-2 GB 5 99 * 24 2 2 2-4 GB 6 100 * 28 2 2 4-8 GB 7 101 * 32 2 2 8-16 GB 8 102 * 4 2 2 <128M 1 103 * 30 4 3 2-4 GB 5 104 * 48 4 3 8-16 GB 8 105 * 32 8 4 1-2 GB 4 106 * 32 8 4 0.9-1GB 4 107 * 10 16 5 <128M 1 108 * 40 16 5 900M 4 109 * 70 64 7 2-4 GB 5 110 * 84 64 7 4-8 GB 6 111 * 108 512 9 4-8 GB 6 112 * 125 1024 10 8-16 GB 8 113 * 125 1024 10 16-32 GB 9 114 */ 115 116 mem = zone->present_pages >> (27 - PAGE_SHIFT); 117 118 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); 119 120 /* 121 * Maximum threshold is 125 122 */ 123 threshold = min(125, threshold); 124 125 return threshold; 126 } 127 128 /* 129 * Refresh the thresholds for each zone. 130 */ 131 static void refresh_zone_stat_thresholds(void) 132 { 133 struct zone *zone; 134 int cpu; 135 int threshold; 136 137 for_each_zone(zone) { 138 139 if (!zone->present_pages) 140 continue; 141 142 threshold = calculate_threshold(zone); 143 144 for_each_online_cpu(cpu) 145 zone_pcp(zone, cpu)->stat_threshold = threshold; 146 } 147 } 148 149 /* 150 * For use when we know that interrupts are disabled. 151 */ 152 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 153 int delta) 154 { 155 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id()); 156 s8 *p = pcp->vm_stat_diff + item; 157 long x; 158 159 x = delta + *p; 160 161 if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) { 162 zone_page_state_add(x, zone, item); 163 x = 0; 164 } 165 *p = x; 166 } 167 EXPORT_SYMBOL(__mod_zone_page_state); 168 169 /* 170 * For an unknown interrupt state 171 */ 172 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 173 int delta) 174 { 175 unsigned long flags; 176 177 local_irq_save(flags); 178 __mod_zone_page_state(zone, item, delta); 179 local_irq_restore(flags); 180 } 181 EXPORT_SYMBOL(mod_zone_page_state); 182 183 /* 184 * Optimized increment and decrement functions. 185 * 186 * These are only for a single page and therefore can take a struct page * 187 * argument instead of struct zone *. This allows the inclusion of the code 188 * generated for page_zone(page) into the optimized functions. 189 * 190 * No overflow check is necessary and therefore the differential can be 191 * incremented or decremented in place which may allow the compilers to 192 * generate better code. 193 * The increment or decrement is known and therefore one boundary check can 194 * be omitted. 195 * 196 * NOTE: These functions are very performance sensitive. Change only 197 * with care. 198 * 199 * Some processors have inc/dec instructions that are atomic vs an interrupt. 200 * However, the code must first determine the differential location in a zone 201 * based on the processor number and then inc/dec the counter. There is no 202 * guarantee without disabling preemption that the processor will not change 203 * in between and therefore the atomicity vs. interrupt cannot be exploited 204 * in a useful way here. 205 */ 206 void __inc_zone_state(struct zone *zone, enum zone_stat_item item) 207 { 208 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id()); 209 s8 *p = pcp->vm_stat_diff + item; 210 211 (*p)++; 212 213 if (unlikely(*p > pcp->stat_threshold)) { 214 int overstep = pcp->stat_threshold / 2; 215 216 zone_page_state_add(*p + overstep, zone, item); 217 *p = -overstep; 218 } 219 } 220 221 void __inc_zone_page_state(struct page *page, enum zone_stat_item item) 222 { 223 __inc_zone_state(page_zone(page), item); 224 } 225 EXPORT_SYMBOL(__inc_zone_page_state); 226 227 void __dec_zone_state(struct zone *zone, enum zone_stat_item item) 228 { 229 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id()); 230 s8 *p = pcp->vm_stat_diff + item; 231 232 (*p)--; 233 234 if (unlikely(*p < - pcp->stat_threshold)) { 235 int overstep = pcp->stat_threshold / 2; 236 237 zone_page_state_add(*p - overstep, zone, item); 238 *p = overstep; 239 } 240 } 241 242 void __dec_zone_page_state(struct page *page, enum zone_stat_item item) 243 { 244 __dec_zone_state(page_zone(page), item); 245 } 246 EXPORT_SYMBOL(__dec_zone_page_state); 247 248 void inc_zone_state(struct zone *zone, enum zone_stat_item item) 249 { 250 unsigned long flags; 251 252 local_irq_save(flags); 253 __inc_zone_state(zone, item); 254 local_irq_restore(flags); 255 } 256 257 void inc_zone_page_state(struct page *page, enum zone_stat_item item) 258 { 259 unsigned long flags; 260 struct zone *zone; 261 262 zone = page_zone(page); 263 local_irq_save(flags); 264 __inc_zone_state(zone, item); 265 local_irq_restore(flags); 266 } 267 EXPORT_SYMBOL(inc_zone_page_state); 268 269 void dec_zone_page_state(struct page *page, enum zone_stat_item item) 270 { 271 unsigned long flags; 272 273 local_irq_save(flags); 274 __dec_zone_page_state(page, item); 275 local_irq_restore(flags); 276 } 277 EXPORT_SYMBOL(dec_zone_page_state); 278 279 /* 280 * Update the zone counters for one cpu. 281 * 282 * The cpu specified must be either the current cpu or a processor that 283 * is not online. If it is the current cpu then the execution thread must 284 * be pinned to the current cpu. 285 * 286 * Note that refresh_cpu_vm_stats strives to only access 287 * node local memory. The per cpu pagesets on remote zones are placed 288 * in the memory local to the processor using that pageset. So the 289 * loop over all zones will access a series of cachelines local to 290 * the processor. 291 * 292 * The call to zone_page_state_add updates the cachelines with the 293 * statistics in the remote zone struct as well as the global cachelines 294 * with the global counters. These could cause remote node cache line 295 * bouncing and will have to be only done when necessary. 296 */ 297 void refresh_cpu_vm_stats(int cpu) 298 { 299 struct zone *zone; 300 int i; 301 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; 302 303 for_each_zone(zone) { 304 struct per_cpu_pageset *p; 305 306 if (!populated_zone(zone)) 307 continue; 308 309 p = zone_pcp(zone, cpu); 310 311 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 312 if (p->vm_stat_diff[i]) { 313 unsigned long flags; 314 int v; 315 316 local_irq_save(flags); 317 v = p->vm_stat_diff[i]; 318 p->vm_stat_diff[i] = 0; 319 local_irq_restore(flags); 320 atomic_long_add(v, &zone->vm_stat[i]); 321 global_diff[i] += v; 322 #ifdef CONFIG_NUMA 323 /* 3 seconds idle till flush */ 324 p->expire = 3; 325 #endif 326 } 327 cond_resched(); 328 #ifdef CONFIG_NUMA 329 /* 330 * Deal with draining the remote pageset of this 331 * processor 332 * 333 * Check if there are pages remaining in this pageset 334 * if not then there is nothing to expire. 335 */ 336 if (!p->expire || !p->pcp.count) 337 continue; 338 339 /* 340 * We never drain zones local to this processor. 341 */ 342 if (zone_to_nid(zone) == numa_node_id()) { 343 p->expire = 0; 344 continue; 345 } 346 347 p->expire--; 348 if (p->expire) 349 continue; 350 351 if (p->pcp.count) 352 drain_zone_pages(zone, &p->pcp); 353 #endif 354 } 355 356 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 357 if (global_diff[i]) 358 atomic_long_add(global_diff[i], &vm_stat[i]); 359 } 360 361 #endif 362 363 #ifdef CONFIG_NUMA 364 /* 365 * zonelist = the list of zones passed to the allocator 366 * z = the zone from which the allocation occurred. 367 * 368 * Must be called with interrupts disabled. 369 */ 370 void zone_statistics(struct zone *preferred_zone, struct zone *z) 371 { 372 if (z->zone_pgdat == preferred_zone->zone_pgdat) { 373 __inc_zone_state(z, NUMA_HIT); 374 } else { 375 __inc_zone_state(z, NUMA_MISS); 376 __inc_zone_state(preferred_zone, NUMA_FOREIGN); 377 } 378 if (z->node == numa_node_id()) 379 __inc_zone_state(z, NUMA_LOCAL); 380 else 381 __inc_zone_state(z, NUMA_OTHER); 382 } 383 #endif 384 385 #ifdef CONFIG_PROC_FS 386 387 #include <linux/seq_file.h> 388 389 static char * const migratetype_names[MIGRATE_TYPES] = { 390 "Unmovable", 391 "Reclaimable", 392 "Movable", 393 "Reserve", 394 "Isolate", 395 }; 396 397 static void *frag_start(struct seq_file *m, loff_t *pos) 398 { 399 pg_data_t *pgdat; 400 loff_t node = *pos; 401 for (pgdat = first_online_pgdat(); 402 pgdat && node; 403 pgdat = next_online_pgdat(pgdat)) 404 --node; 405 406 return pgdat; 407 } 408 409 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 410 { 411 pg_data_t *pgdat = (pg_data_t *)arg; 412 413 (*pos)++; 414 return next_online_pgdat(pgdat); 415 } 416 417 static void frag_stop(struct seq_file *m, void *arg) 418 { 419 } 420 421 /* Walk all the zones in a node and print using a callback */ 422 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, 423 void (*print)(struct seq_file *m, pg_data_t *, struct zone *)) 424 { 425 struct zone *zone; 426 struct zone *node_zones = pgdat->node_zones; 427 unsigned long flags; 428 429 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 430 if (!populated_zone(zone)) 431 continue; 432 433 spin_lock_irqsave(&zone->lock, flags); 434 print(m, pgdat, zone); 435 spin_unlock_irqrestore(&zone->lock, flags); 436 } 437 } 438 439 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, 440 struct zone *zone) 441 { 442 int order; 443 444 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 445 for (order = 0; order < MAX_ORDER; ++order) 446 seq_printf(m, "%6lu ", zone->free_area[order].nr_free); 447 seq_putc(m, '\n'); 448 } 449 450 /* 451 * This walks the free areas for each zone. 452 */ 453 static int frag_show(struct seq_file *m, void *arg) 454 { 455 pg_data_t *pgdat = (pg_data_t *)arg; 456 walk_zones_in_node(m, pgdat, frag_show_print); 457 return 0; 458 } 459 460 static void pagetypeinfo_showfree_print(struct seq_file *m, 461 pg_data_t *pgdat, struct zone *zone) 462 { 463 int order, mtype; 464 465 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { 466 seq_printf(m, "Node %4d, zone %8s, type %12s ", 467 pgdat->node_id, 468 zone->name, 469 migratetype_names[mtype]); 470 for (order = 0; order < MAX_ORDER; ++order) { 471 unsigned long freecount = 0; 472 struct free_area *area; 473 struct list_head *curr; 474 475 area = &(zone->free_area[order]); 476 477 list_for_each(curr, &area->free_list[mtype]) 478 freecount++; 479 seq_printf(m, "%6lu ", freecount); 480 } 481 seq_putc(m, '\n'); 482 } 483 } 484 485 /* Print out the free pages at each order for each migatetype */ 486 static int pagetypeinfo_showfree(struct seq_file *m, void *arg) 487 { 488 int order; 489 pg_data_t *pgdat = (pg_data_t *)arg; 490 491 /* Print header */ 492 seq_printf(m, "%-43s ", "Free pages count per migrate type at order"); 493 for (order = 0; order < MAX_ORDER; ++order) 494 seq_printf(m, "%6d ", order); 495 seq_putc(m, '\n'); 496 497 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print); 498 499 return 0; 500 } 501 502 static void pagetypeinfo_showblockcount_print(struct seq_file *m, 503 pg_data_t *pgdat, struct zone *zone) 504 { 505 int mtype; 506 unsigned long pfn; 507 unsigned long start_pfn = zone->zone_start_pfn; 508 unsigned long end_pfn = start_pfn + zone->spanned_pages; 509 unsigned long count[MIGRATE_TYPES] = { 0, }; 510 511 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 512 struct page *page; 513 514 if (!pfn_valid(pfn)) 515 continue; 516 517 page = pfn_to_page(pfn); 518 mtype = get_pageblock_migratetype(page); 519 520 count[mtype]++; 521 } 522 523 /* Print counts */ 524 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 525 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 526 seq_printf(m, "%12lu ", count[mtype]); 527 seq_putc(m, '\n'); 528 } 529 530 /* Print out the free pages at each order for each migratetype */ 531 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg) 532 { 533 int mtype; 534 pg_data_t *pgdat = (pg_data_t *)arg; 535 536 seq_printf(m, "\n%-23s", "Number of blocks type "); 537 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 538 seq_printf(m, "%12s ", migratetype_names[mtype]); 539 seq_putc(m, '\n'); 540 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print); 541 542 return 0; 543 } 544 545 /* 546 * This prints out statistics in relation to grouping pages by mobility. 547 * It is expensive to collect so do not constantly read the file. 548 */ 549 static int pagetypeinfo_show(struct seq_file *m, void *arg) 550 { 551 pg_data_t *pgdat = (pg_data_t *)arg; 552 553 /* check memoryless node */ 554 if (!node_state(pgdat->node_id, N_HIGH_MEMORY)) 555 return 0; 556 557 seq_printf(m, "Page block order: %d\n", pageblock_order); 558 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages); 559 seq_putc(m, '\n'); 560 pagetypeinfo_showfree(m, pgdat); 561 pagetypeinfo_showblockcount(m, pgdat); 562 563 return 0; 564 } 565 566 const struct seq_operations fragmentation_op = { 567 .start = frag_start, 568 .next = frag_next, 569 .stop = frag_stop, 570 .show = frag_show, 571 }; 572 573 const struct seq_operations pagetypeinfo_op = { 574 .start = frag_start, 575 .next = frag_next, 576 .stop = frag_stop, 577 .show = pagetypeinfo_show, 578 }; 579 580 #ifdef CONFIG_ZONE_DMA 581 #define TEXT_FOR_DMA(xx) xx "_dma", 582 #else 583 #define TEXT_FOR_DMA(xx) 584 #endif 585 586 #ifdef CONFIG_ZONE_DMA32 587 #define TEXT_FOR_DMA32(xx) xx "_dma32", 588 #else 589 #define TEXT_FOR_DMA32(xx) 590 #endif 591 592 #ifdef CONFIG_HIGHMEM 593 #define TEXT_FOR_HIGHMEM(xx) xx "_high", 594 #else 595 #define TEXT_FOR_HIGHMEM(xx) 596 #endif 597 598 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \ 599 TEXT_FOR_HIGHMEM(xx) xx "_movable", 600 601 static const char * const vmstat_text[] = { 602 /* Zoned VM counters */ 603 "nr_free_pages", 604 "nr_inactive", 605 "nr_active", 606 "nr_anon_pages", 607 "nr_mapped", 608 "nr_file_pages", 609 "nr_dirty", 610 "nr_writeback", 611 "nr_slab_reclaimable", 612 "nr_slab_unreclaimable", 613 "nr_page_table_pages", 614 "nr_unstable", 615 "nr_bounce", 616 "nr_vmscan_write", 617 "nr_writeback_temp", 618 619 #ifdef CONFIG_NUMA 620 "numa_hit", 621 "numa_miss", 622 "numa_foreign", 623 "numa_interleave", 624 "numa_local", 625 "numa_other", 626 #endif 627 628 #ifdef CONFIG_VM_EVENT_COUNTERS 629 "pgpgin", 630 "pgpgout", 631 "pswpin", 632 "pswpout", 633 634 TEXTS_FOR_ZONES("pgalloc") 635 636 "pgfree", 637 "pgactivate", 638 "pgdeactivate", 639 640 "pgfault", 641 "pgmajfault", 642 643 TEXTS_FOR_ZONES("pgrefill") 644 TEXTS_FOR_ZONES("pgsteal") 645 TEXTS_FOR_ZONES("pgscan_kswapd") 646 TEXTS_FOR_ZONES("pgscan_direct") 647 648 "pginodesteal", 649 "slabs_scanned", 650 "kswapd_steal", 651 "kswapd_inodesteal", 652 "pageoutrun", 653 "allocstall", 654 655 "pgrotated", 656 #ifdef CONFIG_HUGETLB_PAGE 657 "htlb_buddy_alloc_success", 658 "htlb_buddy_alloc_fail", 659 #endif 660 #endif 661 }; 662 663 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 664 struct zone *zone) 665 { 666 int i; 667 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 668 seq_printf(m, 669 "\n pages free %lu" 670 "\n min %lu" 671 "\n low %lu" 672 "\n high %lu" 673 "\n scanned %lu (a: %lu i: %lu)" 674 "\n spanned %lu" 675 "\n present %lu", 676 zone_page_state(zone, NR_FREE_PAGES), 677 zone->pages_min, 678 zone->pages_low, 679 zone->pages_high, 680 zone->pages_scanned, 681 zone->nr_scan_active, zone->nr_scan_inactive, 682 zone->spanned_pages, 683 zone->present_pages); 684 685 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 686 seq_printf(m, "\n %-12s %lu", vmstat_text[i], 687 zone_page_state(zone, i)); 688 689 seq_printf(m, 690 "\n protection: (%lu", 691 zone->lowmem_reserve[0]); 692 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 693 seq_printf(m, ", %lu", zone->lowmem_reserve[i]); 694 seq_printf(m, 695 ")" 696 "\n pagesets"); 697 for_each_online_cpu(i) { 698 struct per_cpu_pageset *pageset; 699 700 pageset = zone_pcp(zone, i); 701 seq_printf(m, 702 "\n cpu: %i" 703 "\n count: %i" 704 "\n high: %i" 705 "\n batch: %i", 706 i, 707 pageset->pcp.count, 708 pageset->pcp.high, 709 pageset->pcp.batch); 710 #ifdef CONFIG_SMP 711 seq_printf(m, "\n vm stats threshold: %d", 712 pageset->stat_threshold); 713 #endif 714 } 715 seq_printf(m, 716 "\n all_unreclaimable: %u" 717 "\n prev_priority: %i" 718 "\n start_pfn: %lu", 719 zone_is_all_unreclaimable(zone), 720 zone->prev_priority, 721 zone->zone_start_pfn); 722 seq_putc(m, '\n'); 723 } 724 725 /* 726 * Output information about zones in @pgdat. 727 */ 728 static int zoneinfo_show(struct seq_file *m, void *arg) 729 { 730 pg_data_t *pgdat = (pg_data_t *)arg; 731 walk_zones_in_node(m, pgdat, zoneinfo_show_print); 732 return 0; 733 } 734 735 const struct seq_operations zoneinfo_op = { 736 .start = frag_start, /* iterate over all zones. The same as in 737 * fragmentation. */ 738 .next = frag_next, 739 .stop = frag_stop, 740 .show = zoneinfo_show, 741 }; 742 743 static void *vmstat_start(struct seq_file *m, loff_t *pos) 744 { 745 unsigned long *v; 746 #ifdef CONFIG_VM_EVENT_COUNTERS 747 unsigned long *e; 748 #endif 749 int i; 750 751 if (*pos >= ARRAY_SIZE(vmstat_text)) 752 return NULL; 753 754 #ifdef CONFIG_VM_EVENT_COUNTERS 755 v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) 756 + sizeof(struct vm_event_state), GFP_KERNEL); 757 #else 758 v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long), 759 GFP_KERNEL); 760 #endif 761 m->private = v; 762 if (!v) 763 return ERR_PTR(-ENOMEM); 764 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 765 v[i] = global_page_state(i); 766 #ifdef CONFIG_VM_EVENT_COUNTERS 767 e = v + NR_VM_ZONE_STAT_ITEMS; 768 all_vm_events(e); 769 e[PGPGIN] /= 2; /* sectors -> kbytes */ 770 e[PGPGOUT] /= 2; 771 #endif 772 return v + *pos; 773 } 774 775 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 776 { 777 (*pos)++; 778 if (*pos >= ARRAY_SIZE(vmstat_text)) 779 return NULL; 780 return (unsigned long *)m->private + *pos; 781 } 782 783 static int vmstat_show(struct seq_file *m, void *arg) 784 { 785 unsigned long *l = arg; 786 unsigned long off = l - (unsigned long *)m->private; 787 788 seq_printf(m, "%s %lu\n", vmstat_text[off], *l); 789 return 0; 790 } 791 792 static void vmstat_stop(struct seq_file *m, void *arg) 793 { 794 kfree(m->private); 795 m->private = NULL; 796 } 797 798 const struct seq_operations vmstat_op = { 799 .start = vmstat_start, 800 .next = vmstat_next, 801 .stop = vmstat_stop, 802 .show = vmstat_show, 803 }; 804 805 #endif /* CONFIG_PROC_FS */ 806 807 #ifdef CONFIG_SMP 808 static DEFINE_PER_CPU(struct delayed_work, vmstat_work); 809 int sysctl_stat_interval __read_mostly = HZ; 810 811 static void vmstat_update(struct work_struct *w) 812 { 813 refresh_cpu_vm_stats(smp_processor_id()); 814 schedule_delayed_work(&__get_cpu_var(vmstat_work), 815 sysctl_stat_interval); 816 } 817 818 static void __cpuinit start_cpu_timer(int cpu) 819 { 820 struct delayed_work *vmstat_work = &per_cpu(vmstat_work, cpu); 821 822 INIT_DELAYED_WORK_DEFERRABLE(vmstat_work, vmstat_update); 823 schedule_delayed_work_on(cpu, vmstat_work, HZ + cpu); 824 } 825 826 /* 827 * Use the cpu notifier to insure that the thresholds are recalculated 828 * when necessary. 829 */ 830 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb, 831 unsigned long action, 832 void *hcpu) 833 { 834 long cpu = (long)hcpu; 835 836 switch (action) { 837 case CPU_ONLINE: 838 case CPU_ONLINE_FROZEN: 839 start_cpu_timer(cpu); 840 break; 841 case CPU_DOWN_PREPARE: 842 case CPU_DOWN_PREPARE_FROZEN: 843 cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu)); 844 per_cpu(vmstat_work, cpu).work.func = NULL; 845 break; 846 case CPU_DOWN_FAILED: 847 case CPU_DOWN_FAILED_FROZEN: 848 start_cpu_timer(cpu); 849 break; 850 case CPU_DEAD: 851 case CPU_DEAD_FROZEN: 852 refresh_zone_stat_thresholds(); 853 break; 854 default: 855 break; 856 } 857 return NOTIFY_OK; 858 } 859 860 static struct notifier_block __cpuinitdata vmstat_notifier = 861 { &vmstat_cpuup_callback, NULL, 0 }; 862 863 static int __init setup_vmstat(void) 864 { 865 int cpu; 866 867 refresh_zone_stat_thresholds(); 868 register_cpu_notifier(&vmstat_notifier); 869 870 for_each_online_cpu(cpu) 871 start_cpu_timer(cpu); 872 return 0; 873 } 874 module_init(setup_vmstat) 875 #endif 876