SAFE public projects git trees. - safe/jmp/linux-2.6/blob - mm/vmstat.c

   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 #include <linux/fs.h>
  12 #include <linux/mm.h>
  13 #include <linux/err.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/cpu.h>
  17 #include <linux/vmstat.h>
  18 #include <linux/sched.h>
  19
  20 #ifdef CONFIG_VM_EVENT_COUNTERS
  21 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
  22 EXPORT_PER_CPU_SYMBOL(vm_event_states);
  23
  24 static void sum_vm_events(unsigned long *ret, const struct cpumask *cpumask)
  25 {
  26         int cpu;
  27         int i;
  28
  29         memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
  30
  31         for_each_cpu(cpu, cpumask) {
  32                 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
  33
  34                 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
  35                         ret[i] += this->event[i];
  36         }
  37 }
  38
  39 /*
  40  * Accumulate the vm event counters across all CPUs.
  41  * The result is unavoidably approximate - it can change
  42  * during and after execution of this function.
  43 */
  44 void all_vm_events(unsigned long *ret)
  45 {
  46         get_online_cpus();
  47         sum_vm_events(ret, cpu_online_mask);
  48         put_online_cpus();
  49 }
  50 EXPORT_SYMBOL_GPL(all_vm_events);
  51
  52 #ifdef CONFIG_HOTPLUG
  53 /*
  54  * Fold the foreign cpu events into our own.
  55  *
  56  * This is adding to the events on one processor
  57  * but keeps the global counts constant.
  58  */
  59 void vm_events_fold_cpu(int cpu)
  60 {
  61         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
  62         int i;
  63
  64         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
  65                 count_vm_events(i, fold_state->event[i]);
  66                 fold_state->event[i] = 0;
  67         }
  68 }
  69 #endif /* CONFIG_HOTPLUG */
  70
  71 #endif /* CONFIG_VM_EVENT_COUNTERS */
  72
  73 /*
  74  * Manage combined zone based / global counters
  75  *
  76  * vm_stat contains the global counters
  77  */
  78 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
  79 EXPORT_SYMBOL(vm_stat);
  80
  81 #ifdef CONFIG_SMP
  82
  83 static int calculate_threshold(struct zone *zone)
  84 {
  85         int threshold;
  86         int mem;        /* memory in 128 MB units */
  87
  88         /*
  89          * The threshold scales with the number of processors and the amount
  90          * of memory per zone. More memory means that we can defer updates for
  91          * longer, more processors could lead to more contention.
  92          * fls() is used to have a cheap way of logarithmic scaling.
  93          *
  94          * Some sample thresholds:
  95          *
  96          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
  97          * ------------------------------------------------------------------
  98          * 8            1               1       0.9-1 GB        4
  99          * 16           2               2       0.9-1 GB        4
 100          * 20           2               2       1-2 GB          5
 101          * 24           2               2       2-4 GB          6
 102          * 28           2               2       4-8 GB          7
 103          * 32           2               2       8-16 GB         8
 104          * 4            2               2       <128M           1
 105          * 30           4               3       2-4 GB          5
 106          * 48           4               3       8-16 GB         8
 107          * 32           8               4       1-2 GB          4
 108          * 32           8               4       0.9-1GB         4
 109          * 10           16              5       <128M           1
 110          * 40           16              5       900M            4
 111          * 70           64              7       2-4 GB          5
 112          * 84           64              7       4-8 GB          6
 113          * 108          512             9       4-8 GB          6
 114          * 125          1024            10      8-16 GB         8
 115          * 125          1024            10      16-32 GB        9
 116          */
 117
 118         mem = zone->present_pages >> (27 - PAGE_SHIFT);
 119
 120         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
 121
 122         /*
 123          * Maximum threshold is 125
 124          */
 125         threshold = min(125, threshold);
 126
 127         return threshold;
 128 }
 129
 130 /*
 131  * Refresh the thresholds for each zone.
 132  */
 133 static void refresh_zone_stat_thresholds(void)
 134 {
 135         struct zone *zone;
 136         int cpu;
 137         int threshold;
 138
 139         for_each_populated_zone(zone) {
 140                 threshold = calculate_threshold(zone);
 141
 142                 for_each_online_cpu(cpu)
 143                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 144                                                         = threshold;
 145         }
 146 }
 147
 148 /*
 149  * For use when we know that interrupts are disabled.
 150  */
 151 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 152                                 int delta)
 153 {
 154         struct per_cpu_pageset *pcp = this_cpu_ptr(zone->pageset);
 155
 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 = this_cpu_ptr(zone->pageset);
 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 = this_cpu_ptr(zone->pageset);
 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_populated_zone(zone) {
 304                 struct per_cpu_pageset *p;
 305
 306                 p = per_cpu_ptr(zone->pageset, cpu);
 307
 308                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 309                         if (p->vm_stat_diff[i]) {
 310                                 unsigned long flags;
 311                                 int v;
 312
 313                                 local_irq_save(flags);
 314                                 v = p->vm_stat_diff[i];
 315                                 p->vm_stat_diff[i] = 0;
 316                                 local_irq_restore(flags);
 317                                 atomic_long_add(v, &zone->vm_stat[i]);
 318                                 global_diff[i] += v;
 319 #ifdef CONFIG_NUMA
 320                                 /* 3 seconds idle till flush */
 321                                 p->expire = 3;
 322 #endif
 323                         }
 324                 cond_resched();
 325 #ifdef CONFIG_NUMA
 326                 /*
 327                  * Deal with draining the remote pageset of this
 328                  * processor
 329                  *
 330                  * Check if there are pages remaining in this pageset
 331                  * if not then there is nothing to expire.
 332                  */
 333                 if (!p->expire || !p->pcp.count)
 334                         continue;
 335
 336                 /*
 337                  * We never drain zones local to this processor.
 338                  */
 339                 if (zone_to_nid(zone) == numa_node_id()) {
 340                         p->expire = 0;
 341                         continue;
 342                 }
 343
 344                 p->expire--;
 345                 if (p->expire)
 346                         continue;
 347
 348                 if (p->pcp.count)
 349                         drain_zone_pages(zone, &p->pcp);
 350 #endif
 351         }
 352
 353         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 354                 if (global_diff[i])
 355                         atomic_long_add(global_diff[i], &vm_stat[i]);
 356 }
 357
 358 #endif
 359
 360 #ifdef CONFIG_NUMA
 361 /*
 362  * zonelist = the list of zones passed to the allocator
 363  * z        = the zone from which the allocation occurred.
 364  *
 365  * Must be called with interrupts disabled.
 366  */
 367 void zone_statistics(struct zone *preferred_zone, struct zone *z)
 368 {
 369         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
 370                 __inc_zone_state(z, NUMA_HIT);
 371         } else {
 372                 __inc_zone_state(z, NUMA_MISS);
 373                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
 374         }
 375         if (z->node == numa_node_id())
 376                 __inc_zone_state(z, NUMA_LOCAL);
 377         else
 378                 __inc_zone_state(z, NUMA_OTHER);
 379 }
 380 #endif
 381
 382 #ifdef CONFIG_COMPACTION
 383 struct contig_page_info {
 384         unsigned long free_pages;
 385         unsigned long free_blocks_total;
 386         unsigned long free_blocks_suitable;
 387 };
 388
 389 /*
 390  * Calculate the number of free pages in a zone, how many contiguous
 391  * pages are free and how many are large enough to satisfy an allocation of
 392  * the target size. Note that this function makes no attempt to estimate
 393  * how many suitable free blocks there *might* be if MOVABLE pages were
 394  * migrated. Calculating that is possible, but expensive and can be
 395  * figured out from userspace
 396  */
 397 static void fill_contig_page_info(struct zone *zone,
 398                                 unsigned int suitable_order,
 399                                 struct contig_page_info *info)
 400 {
 401         unsigned int order;
 402
 403         info->free_pages = 0;
 404         info->free_blocks_total = 0;
 405         info->free_blocks_suitable = 0;
 406
 407         for (order = 0; order < MAX_ORDER; order++) {
 408                 unsigned long blocks;
 409
 410                 /* Count number of free blocks */
 411                 blocks = zone->free_area[order].nr_free;
 412                 info->free_blocks_total += blocks;
 413
 414                 /* Count free base pages */
 415                 info->free_pages += blocks << order;
 416
 417                 /* Count the suitable free blocks */
 418                 if (order >= suitable_order)
 419                         info->free_blocks_suitable += blocks <<
 420                                                 (order - suitable_order);
 421         }
 422 }
 423 #endif
 424
 425 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
 426 #include <linux/proc_fs.h>
 427 #include <linux/seq_file.h>
 428
 429 static char * const migratetype_names[MIGRATE_TYPES] = {
 430         "Unmovable",
 431         "Reclaimable",
 432         "Movable",
 433         "Reserve",
 434         "Isolate",
 435 };
 436
 437 static void *frag_start(struct seq_file *m, loff_t *pos)
 438 {
 439         pg_data_t *pgdat;
 440         loff_t node = *pos;
 441         for (pgdat = first_online_pgdat();
 442              pgdat && node;
 443              pgdat = next_online_pgdat(pgdat))
 444                 --node;
 445
 446         return pgdat;
 447 }
 448
 449 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
 450 {
 451         pg_data_t *pgdat = (pg_data_t *)arg;
 452
 453         (*pos)++;
 454         return next_online_pgdat(pgdat);
 455 }
 456
 457 static void frag_stop(struct seq_file *m, void *arg)
 458 {
 459 }
 460
 461 /* Walk all the zones in a node and print using a callback */
 462 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 463                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 464 {
 465         struct zone *zone;
 466         struct zone *node_zones = pgdat->node_zones;
 467         unsigned long flags;
 468
 469         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
 470                 if (!populated_zone(zone))
 471                         continue;
 472
 473                 spin_lock_irqsave(&zone->lock, flags);
 474                 print(m, pgdat, zone);
 475                 spin_unlock_irqrestore(&zone->lock, flags);
 476         }
 477 }
 478 #endif
 479
 480 #ifdef CONFIG_PROC_FS
 481 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
 482                                                 struct zone *zone)
 483 {
 484         int order;
 485
 486         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 487         for (order = 0; order < MAX_ORDER; ++order)
 488                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
 489         seq_putc(m, '\n');
 490 }
 491
 492 /*
 493  * This walks the free areas for each zone.
 494  */
 495 static int frag_show(struct seq_file *m, void *arg)
 496 {
 497         pg_data_t *pgdat = (pg_data_t *)arg;
 498         walk_zones_in_node(m, pgdat, frag_show_print);
 499         return 0;
 500 }
 501
 502 static void pagetypeinfo_showfree_print(struct seq_file *m,
 503                                         pg_data_t *pgdat, struct zone *zone)
 504 {
 505         int order, mtype;
 506
 507         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
 508                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
 509                                         pgdat->node_id,
 510                                         zone->name,
 511                                         migratetype_names[mtype]);
 512                 for (order = 0; order < MAX_ORDER; ++order) {
 513                         unsigned long freecount = 0;
 514                         struct free_area *area;
 515                         struct list_head *curr;
 516
 517                         area = &(zone->free_area[order]);
 518
 519                         list_for_each(curr, &area->free_list[mtype])
 520                                 freecount++;
 521                         seq_printf(m, "%6lu ", freecount);
 522                 }
 523                 seq_putc(m, '\n');
 524         }
 525 }
 526
 527 /* Print out the free pages at each order for each migatetype */
 528 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
 529 {
 530         int order;
 531         pg_data_t *pgdat = (pg_data_t *)arg;
 532
 533         /* Print header */
 534         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
 535         for (order = 0; order < MAX_ORDER; ++order)
 536                 seq_printf(m, "%6d ", order);
 537         seq_putc(m, '\n');
 538
 539         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
 540
 541         return 0;
 542 }
 543
 544 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 545                                         pg_data_t *pgdat, struct zone *zone)
 546 {
 547         int mtype;
 548         unsigned long pfn;
 549         unsigned long start_pfn = zone->zone_start_pfn;
 550         unsigned long end_pfn = start_pfn + zone->spanned_pages;
 551         unsigned long count[MIGRATE_TYPES] = { 0, };
 552
 553         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
 554                 struct page *page;
 555
 556                 if (!pfn_valid(pfn))
 557                         continue;
 558
 559                 page = pfn_to_page(pfn);
 560
 561                 /* Watch for unexpected holes punched in the memmap */
 562                 if (!memmap_valid_within(pfn, page, zone))
 563                         continue;
 564
 565                 mtype = get_pageblock_migratetype(page);
 566
 567                 if (mtype < MIGRATE_TYPES)
 568                         count[mtype]++;
 569         }
 570
 571         /* Print counts */
 572         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 573         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 574                 seq_printf(m, "%12lu ", count[mtype]);
 575         seq_putc(m, '\n');
 576 }
 577
 578 /* Print out the free pages at each order for each migratetype */
 579 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
 580 {
 581         int mtype;
 582         pg_data_t *pgdat = (pg_data_t *)arg;
 583
 584         seq_printf(m, "\n%-23s", "Number of blocks type ");
 585         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 586                 seq_printf(m, "%12s ", migratetype_names[mtype]);
 587         seq_putc(m, '\n');
 588         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
 589
 590         return 0;
 591 }
 592
 593 /*
 594  * This prints out statistics in relation to grouping pages by mobility.
 595  * It is expensive to collect so do not constantly read the file.
 596  */
 597 static int pagetypeinfo_show(struct seq_file *m, void *arg)
 598 {
 599         pg_data_t *pgdat = (pg_data_t *)arg;
 600
 601         /* check memoryless node */
 602         if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
 603                 return 0;
 604
 605         seq_printf(m, "Page block order: %d\n", pageblock_order);
 606         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
 607         seq_putc(m, '\n');
 608         pagetypeinfo_showfree(m, pgdat);
 609         pagetypeinfo_showblockcount(m, pgdat);
 610
 611         return 0;
 612 }
 613
 614 static const struct seq_operations fragmentation_op = {
 615         .start  = frag_start,
 616         .next   = frag_next,
 617         .stop   = frag_stop,
 618         .show   = frag_show,
 619 };
 620
 621 static int fragmentation_open(struct inode *inode, struct file *file)
 622 {
 623         return seq_open(file, &fragmentation_op);
 624 }
 625
 626 static const struct file_operations fragmentation_file_operations = {
 627         .open           = fragmentation_open,
 628         .read           = seq_read,
 629         .llseek         = seq_lseek,
 630         .release        = seq_release,
 631 };
 632
 633 static const struct seq_operations pagetypeinfo_op = {
 634         .start  = frag_start,
 635         .next   = frag_next,
 636         .stop   = frag_stop,
 637         .show   = pagetypeinfo_show,
 638 };
 639
 640 static int pagetypeinfo_open(struct inode *inode, struct file *file)
 641 {
 642         return seq_open(file, &pagetypeinfo_op);
 643 }
 644
 645 static const struct file_operations pagetypeinfo_file_ops = {
 646         .open           = pagetypeinfo_open,
 647         .read           = seq_read,
 648         .llseek         = seq_lseek,
 649         .release        = seq_release,
 650 };
 651
 652 #ifdef CONFIG_ZONE_DMA
 653 #define TEXT_FOR_DMA(xx) xx "_dma",
 654 #else
 655 #define TEXT_FOR_DMA(xx)
 656 #endif
 657
 658 #ifdef CONFIG_ZONE_DMA32
 659 #define TEXT_FOR_DMA32(xx) xx "_dma32",
 660 #else
 661 #define TEXT_FOR_DMA32(xx)
 662 #endif
 663
 664 #ifdef CONFIG_HIGHMEM
 665 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
 666 #else
 667 #define TEXT_FOR_HIGHMEM(xx)
 668 #endif
 669
 670 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
 671                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
 672
 673 static const char * const vmstat_text[] = {
 674         /* Zoned VM counters */
 675         "nr_free_pages",
 676         "nr_inactive_anon",
 677         "nr_active_anon",
 678         "nr_inactive_file",
 679         "nr_active_file",
 680         "nr_unevictable",
 681         "nr_mlock",
 682         "nr_anon_pages",
 683         "nr_mapped",
 684         "nr_file_pages",
 685         "nr_dirty",
 686         "nr_writeback",
 687         "nr_slab_reclaimable",
 688         "nr_slab_unreclaimable",
 689         "nr_page_table_pages",
 690         "nr_kernel_stack",
 691         "nr_unstable",
 692         "nr_bounce",
 693         "nr_vmscan_write",
 694         "nr_writeback_temp",
 695         "nr_isolated_anon",
 696         "nr_isolated_file",
 697         "nr_shmem",
 698 #ifdef CONFIG_NUMA
 699         "numa_hit",
 700         "numa_miss",
 701         "numa_foreign",
 702         "numa_interleave",
 703         "numa_local",
 704         "numa_other",
 705 #endif
 706
 707 #ifdef CONFIG_VM_EVENT_COUNTERS
 708         "pgpgin",
 709         "pgpgout",
 710         "pswpin",
 711         "pswpout",
 712
 713         TEXTS_FOR_ZONES("pgalloc")
 714
 715         "pgfree",
 716         "pgactivate",
 717         "pgdeactivate",
 718
 719         "pgfault",
 720         "pgmajfault",
 721
 722         TEXTS_FOR_ZONES("pgrefill")
 723         TEXTS_FOR_ZONES("pgsteal")
 724         TEXTS_FOR_ZONES("pgscan_kswapd")
 725         TEXTS_FOR_ZONES("pgscan_direct")
 726
 727 #ifdef CONFIG_NUMA
 728         "zone_reclaim_failed",
 729 #endif
 730         "pginodesteal",
 731         "slabs_scanned",
 732         "kswapd_steal",
 733         "kswapd_inodesteal",
 734         "kswapd_low_wmark_hit_quickly",
 735         "kswapd_high_wmark_hit_quickly",
 736         "kswapd_skip_congestion_wait",
 737         "pageoutrun",
 738         "allocstall",
 739
 740         "pgrotated",
 741 #ifdef CONFIG_HUGETLB_PAGE
 742         "htlb_buddy_alloc_success",
 743         "htlb_buddy_alloc_fail",
 744 #endif
 745         "unevictable_pgs_culled",
 746         "unevictable_pgs_scanned",
 747         "unevictable_pgs_rescued",
 748         "unevictable_pgs_mlocked",
 749         "unevictable_pgs_munlocked",
 750         "unevictable_pgs_cleared",
 751         "unevictable_pgs_stranded",
 752         "unevictable_pgs_mlockfreed",
 753 #endif
 754 };
 755
 756 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 757                                                         struct zone *zone)
 758 {
 759         int i;
 760         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
 761         seq_printf(m,
 762                    "\n  pages free     %lu"
 763                    "\n        min      %lu"
 764                    "\n        low      %lu"
 765                    "\n        high     %lu"
 766                    "\n        scanned  %lu"
 767                    "\n        spanned  %lu"
 768                    "\n        present  %lu",
 769                    zone_page_state(zone, NR_FREE_PAGES),
 770                    min_wmark_pages(zone),
 771                    low_wmark_pages(zone),
 772                    high_wmark_pages(zone),
 773                    zone->pages_scanned,
 774                    zone->spanned_pages,
 775                    zone->present_pages);
 776
 777         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 778                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
 779                                 zone_page_state(zone, i));
 780
 781         seq_printf(m,
 782                    "\n        protection: (%lu",
 783                    zone->lowmem_reserve[0]);
 784         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
 785                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
 786         seq_printf(m,
 787                    ")"
 788                    "\n  pagesets");
 789         for_each_online_cpu(i) {
 790                 struct per_cpu_pageset *pageset;
 791
 792                 pageset = per_cpu_ptr(zone->pageset, i);
 793                 seq_printf(m,
 794                            "\n    cpu: %i"
 795                            "\n              count: %i"
 796                            "\n              high:  %i"
 797                            "\n              batch: %i",
 798                            i,
 799                            pageset->pcp.count,
 800                            pageset->pcp.high,
 801                            pageset->pcp.batch);
 802 #ifdef CONFIG_SMP
 803                 seq_printf(m, "\n  vm stats threshold: %d",
 804                                 pageset->stat_threshold);
 805 #endif
 806         }
 807         seq_printf(m,
 808                    "\n  all_unreclaimable: %u"
 809                    "\n  prev_priority:     %i"
 810                    "\n  start_pfn:         %lu"
 811                    "\n  inactive_ratio:    %u",
 812                    zone->all_unreclaimable,
 813                    zone->prev_priority,
 814                    zone->zone_start_pfn,
 815                    zone->inactive_ratio);
 816         seq_putc(m, '\n');
 817 }
 818
 819 /*
 820  * Output information about zones in @pgdat.
 821  */
 822 static int zoneinfo_show(struct seq_file *m, void *arg)
 823 {
 824         pg_data_t *pgdat = (pg_data_t *)arg;
 825         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
 826         return 0;
 827 }
 828
 829 static const struct seq_operations zoneinfo_op = {
 830         .start  = frag_start, /* iterate over all zones. The same as in
 831                                * fragmentation. */
 832         .next   = frag_next,
 833         .stop   = frag_stop,
 834         .show   = zoneinfo_show,
 835 };
 836
 837 static int zoneinfo_open(struct inode *inode, struct file *file)
 838 {
 839         return seq_open(file, &zoneinfo_op);
 840 }
 841
 842 static const struct file_operations proc_zoneinfo_file_operations = {
 843         .open           = zoneinfo_open,
 844         .read           = seq_read,
 845         .llseek         = seq_lseek,
 846         .release        = seq_release,
 847 };
 848
 849 static void *vmstat_start(struct seq_file *m, loff_t *pos)
 850 {
 851         unsigned long *v;
 852 #ifdef CONFIG_VM_EVENT_COUNTERS
 853         unsigned long *e;
 854 #endif
 855         int i;
 856
 857         if (*pos >= ARRAY_SIZE(vmstat_text))
 858                 return NULL;
 859
 860 #ifdef CONFIG_VM_EVENT_COUNTERS
 861         v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
 862                         + sizeof(struct vm_event_state), GFP_KERNEL);
 863 #else
 864         v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
 865                         GFP_KERNEL);
 866 #endif
 867         m->private = v;
 868         if (!v)
 869                 return ERR_PTR(-ENOMEM);
 870         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 871                 v[i] = global_page_state(i);
 872 #ifdef CONFIG_VM_EVENT_COUNTERS
 873         e = v + NR_VM_ZONE_STAT_ITEMS;
 874         all_vm_events(e);
 875         e[PGPGIN] /= 2;         /* sectors -> kbytes */
 876         e[PGPGOUT] /= 2;
 877 #endif
 878         return v + *pos;
 879 }
 880
 881 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
 882 {
 883         (*pos)++;
 884         if (*pos >= ARRAY_SIZE(vmstat_text))
 885                 return NULL;
 886         return (unsigned long *)m->private + *pos;
 887 }
 888
 889 static int vmstat_show(struct seq_file *m, void *arg)
 890 {
 891         unsigned long *l = arg;
 892         unsigned long off = l - (unsigned long *)m->private;
 893
 894         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
 895         return 0;
 896 }
 897
 898 static void vmstat_stop(struct seq_file *m, void *arg)
 899 {
 900         kfree(m->private);
 901         m->private = NULL;
 902 }
 903
 904 static const struct seq_operations vmstat_op = {
 905         .start  = vmstat_start,
 906         .next   = vmstat_next,
 907         .stop   = vmstat_stop,
 908         .show   = vmstat_show,
 909 };
 910
 911 static int vmstat_open(struct inode *inode, struct file *file)
 912 {
 913         return seq_open(file, &vmstat_op);
 914 }
 915
 916 static const struct file_operations proc_vmstat_file_operations = {
 917         .open           = vmstat_open,
 918         .read           = seq_read,
 919         .llseek         = seq_lseek,
 920         .release        = seq_release,
 921 };
 922 #endif /* CONFIG_PROC_FS */
 923
 924 #ifdef CONFIG_SMP
 925 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
 926 int sysctl_stat_interval __read_mostly = HZ;
 927
 928 static void vmstat_update(struct work_struct *w)
 929 {
 930         refresh_cpu_vm_stats(smp_processor_id());
 931         schedule_delayed_work(&__get_cpu_var(vmstat_work),
 932                 round_jiffies_relative(sysctl_stat_interval));
 933 }
 934
 935 static void __cpuinit start_cpu_timer(int cpu)
 936 {
 937         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
 938
 939         INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
 940         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
 941 }
 942
 943 /*
 944  * Use the cpu notifier to insure that the thresholds are recalculated
 945  * when necessary.
 946  */
 947 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
 948                 unsigned long action,
 949                 void *hcpu)
 950 {
 951         long cpu = (long)hcpu;
 952
 953         switch (action) {
 954         case CPU_ONLINE:
 955         case CPU_ONLINE_FROZEN:
 956                 start_cpu_timer(cpu);
 957                 node_set_state(cpu_to_node(cpu), N_CPU);
 958                 break;
 959         case CPU_DOWN_PREPARE:
 960         case CPU_DOWN_PREPARE_FROZEN:
 961                 cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
 962                 per_cpu(vmstat_work, cpu).work.func = NULL;
 963                 break;
 964         case CPU_DOWN_FAILED:
 965         case CPU_DOWN_FAILED_FROZEN:
 966                 start_cpu_timer(cpu);
 967                 break;
 968         case CPU_DEAD:
 969         case CPU_DEAD_FROZEN:
 970                 refresh_zone_stat_thresholds();
 971                 break;
 972         default:
 973                 break;
 974         }
 975         return NOTIFY_OK;
 976 }
 977
 978 static struct notifier_block __cpuinitdata vmstat_notifier =
 979         { &vmstat_cpuup_callback, NULL, 0 };
 980 #endif
 981
 982 static int __init setup_vmstat(void)
 983 {
 984 #ifdef CONFIG_SMP
 985         int cpu;
 986
 987         refresh_zone_stat_thresholds();
 988         register_cpu_notifier(&vmstat_notifier);
 989
 990         for_each_online_cpu(cpu)
 991                 start_cpu_timer(cpu);
 992 #endif
 993 #ifdef CONFIG_PROC_FS
 994         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
 995         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
 996         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
 997         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
 998 #endif
 999         return 0;
1000 }
1001 module_init(setup_vmstat)
1002
1003 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1004 #include <linux/debugfs.h>
1005
1006 static struct dentry *extfrag_debug_root;
1007
1008 /*
1009  * Return an index indicating how much of the available free memory is
1010  * unusable for an allocation of the requested size.
1011  */
1012 static int unusable_free_index(unsigned int order,
1013                                 struct contig_page_info *info)
1014 {
1015         /* No free memory is interpreted as all free memory is unusable */
1016         if (info->free_pages == 0)
1017                 return 1000;
1018
1019         /*
1020          * Index should be a value between 0 and 1. Return a value to 3
1021          * decimal places.
1022          *
1023          * 0 => no fragmentation
1024          * 1 => high fragmentation
1025          */
1026         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1027
1028 }
1029
1030 static void unusable_show_print(struct seq_file *m,
1031                                         pg_data_t *pgdat, struct zone *zone)
1032 {
1033         unsigned int order;
1034         int index;
1035         struct contig_page_info info;
1036
1037         seq_printf(m, "Node %d, zone %8s ",
1038                                 pgdat->node_id,
1039                                 zone->name);
1040         for (order = 0; order < MAX_ORDER; ++order) {
1041                 fill_contig_page_info(zone, order, &info);
1042                 index = unusable_free_index(order, &info);
1043                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1044         }
1045
1046         seq_putc(m, '\n');
1047 }
1048
1049 /*
1050  * Display unusable free space index
1051  *
1052  * The unusable free space index measures how much of the available free
1053  * memory cannot be used to satisfy an allocation of a given size and is a
1054  * value between 0 and 1. The higher the value, the more of free memory is
1055  * unusable and by implication, the worse the external fragmentation is. This
1056  * can be expressed as a percentage by multiplying by 100.
1057  */
1058 static int unusable_show(struct seq_file *m, void *arg)
1059 {
1060         pg_data_t *pgdat = (pg_data_t *)arg;
1061
1062         /* check memoryless node */
1063         if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1064                 return 0;
1065
1066         walk_zones_in_node(m, pgdat, unusable_show_print);
1067
1068         return 0;
1069 }
1070
1071 static const struct seq_operations unusable_op = {
1072         .start  = frag_start,
1073         .next   = frag_next,
1074         .stop   = frag_stop,
1075         .show   = unusable_show,
1076 };
1077
1078 static int unusable_open(struct inode *inode, struct file *file)
1079 {
1080         return seq_open(file, &unusable_op);
1081 }
1082
1083 static const struct file_operations unusable_file_ops = {
1084         .open           = unusable_open,
1085         .read           = seq_read,
1086         .llseek         = seq_lseek,
1087         .release        = seq_release,
1088 };
1089
1090 static int __init extfrag_debug_init(void)
1091 {
1092         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1093         if (!extfrag_debug_root)
1094                 return -ENOMEM;
1095
1096         if (!debugfs_create_file("unusable_index", 0444,
1097                         extfrag_debug_root, NULL, &unusable_file_ops))
1098                 return -ENOMEM;
1099
1100         return 0;
1101 }
1102
1103 module_init(extfrag_debug_init);
1104 #endif