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/cpu.h>
  16 #include <linux/vmstat.h>
  17 #include <linux/sched.h>
  18
  19 #ifdef CONFIG_VM_EVENT_COUNTERS
  20 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
  21 EXPORT_PER_CPU_SYMBOL(vm_event_states);
  22
  23 static void sum_vm_events(unsigned long *ret, const struct cpumask *cpumask)
  24 {
  25         int cpu;
  26         int i;
  27
  28         memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
  29
  30         for_each_cpu(cpu, cpumask) {
  31                 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
  32
  33                 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
  34                         ret[i] += this->event[i];
  35         }
  36 }
  37
  38 /*
  39  * Accumulate the vm event counters across all CPUs.
  40  * The result is unavoidably approximate - it can change
  41  * during and after execution of this function.
  42 */
  43 void all_vm_events(unsigned long *ret)
  44 {
  45         get_online_cpus();
  46         sum_vm_events(ret, cpu_online_mask);
  47         put_online_cpus();
  48 }
  49 EXPORT_SYMBOL_GPL(all_vm_events);
  50
  51 #ifdef CONFIG_HOTPLUG
  52 /*
  53  * Fold the foreign cpu events into our own.
  54  *
  55  * This is adding to the events on one processor
  56  * but keeps the global counts constant.
  57  */
  58 void vm_events_fold_cpu(int cpu)
  59 {
  60         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
  61         int i;
  62
  63         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
  64                 count_vm_events(i, fold_state->event[i]);
  65                 fold_state->event[i] = 0;
  66         }
  67 }
  68 #endif /* CONFIG_HOTPLUG */
  69
  70 #endif /* CONFIG_VM_EVENT_COUNTERS */
  71
  72 /*
  73  * Manage combined zone based / global counters
  74  *
  75  * vm_stat contains the global counters
  76  */
  77 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
  78 EXPORT_SYMBOL(vm_stat);
  79
  80 #ifdef CONFIG_SMP
  81
  82 static int calculate_threshold(struct zone *zone)
  83 {
  84         int threshold;
  85         int mem;        /* memory in 128 MB units */
  86
  87         /*
  88          * The threshold scales with the number of processors and the amount
  89          * of memory per zone. More memory means that we can defer updates for
  90          * longer, more processors could lead to more contention.
  91          * fls() is used to have a cheap way of logarithmic scaling.
  92          *
  93          * Some sample thresholds:
  94          *
  95          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
  96          * ------------------------------------------------------------------
  97          * 8            1               1       0.9-1 GB        4
  98          * 16           2               2       0.9-1 GB        4
  99          * 20           2               2       1-2 GB          5
 100          * 24           2               2       2-4 GB          6
 101          * 28           2               2       4-8 GB          7
 102          * 32           2               2       8-16 GB         8
 103          * 4            2               2       <128M           1
 104          * 30           4               3       2-4 GB          5
 105          * 48           4               3       8-16 GB         8
 106          * 32           8               4       1-2 GB          4
 107          * 32           8               4       0.9-1GB         4
 108          * 10           16              5       <128M           1
 109          * 40           16              5       900M            4
 110          * 70           64              7       2-4 GB          5
 111          * 84           64              7       4-8 GB          6
 112          * 108          512             9       4-8 GB          6
 113          * 125          1024            10      8-16 GB         8
 114          * 125          1024            10      16-32 GB        9
 115          */
 116
 117         mem = zone->present_pages >> (27 - PAGE_SHIFT);
 118
 119         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
 120
 121         /*
 122          * Maximum threshold is 125
 123          */
 124         threshold = min(125, threshold);
 125
 126         return threshold;
 127 }
 128
 129 /*
 130  * Refresh the thresholds for each zone.
 131  */
 132 static void refresh_zone_stat_thresholds(void)
 133 {
 134         struct zone *zone;
 135         int cpu;
 136         int threshold;
 137
 138         for_each_populated_zone(zone) {
 139                 threshold = calculate_threshold(zone);
 140
 141                 for_each_online_cpu(cpu)
 142                         zone_pcp(zone, cpu)->stat_threshold = threshold;
 143         }
 144 }
 145
 146 /*
 147  * For use when we know that interrupts are disabled.
 148  */
 149 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 150                                 int delta)
 151 {
 152         struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
 153         s8 *p = pcp->vm_stat_diff + item;
 154         long x;
 155
 156         x = delta + *p;
 157
 158         if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
 159                 zone_page_state_add(x, zone, item);
 160                 x = 0;
 161         }
 162         *p = x;
 163 }
 164 EXPORT_SYMBOL(__mod_zone_page_state);
 165
 166 /*
 167  * For an unknown interrupt state
 168  */
 169 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 170                                         int delta)
 171 {
 172         unsigned long flags;
 173
 174         local_irq_save(flags);
 175         __mod_zone_page_state(zone, item, delta);
 176         local_irq_restore(flags);
 177 }
 178 EXPORT_SYMBOL(mod_zone_page_state);
 179
 180 /*
 181  * Optimized increment and decrement functions.
 182  *
 183  * These are only for a single page and therefore can take a struct page *
 184  * argument instead of struct zone *. This allows the inclusion of the code
 185  * generated for page_zone(page) into the optimized functions.
 186  *
 187  * No overflow check is necessary and therefore the differential can be
 188  * incremented or decremented in place which may allow the compilers to
 189  * generate better code.
 190  * The increment or decrement is known and therefore one boundary check can
 191  * be omitted.
 192  *
 193  * NOTE: These functions are very performance sensitive. Change only
 194  * with care.
 195  *
 196  * Some processors have inc/dec instructions that are atomic vs an interrupt.
 197  * However, the code must first determine the differential location in a zone
 198  * based on the processor number and then inc/dec the counter. There is no
 199  * guarantee without disabling preemption that the processor will not change
 200  * in between and therefore the atomicity vs. interrupt cannot be exploited
 201  * in a useful way here.
 202  */
 203 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 204 {
 205         struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
 206         s8 *p = pcp->vm_stat_diff + item;
 207
 208         (*p)++;
 209
 210         if (unlikely(*p > pcp->stat_threshold)) {
 211                 int overstep = pcp->stat_threshold / 2;
 212
 213                 zone_page_state_add(*p + overstep, zone, item);
 214                 *p = -overstep;
 215         }
 216 }
 217
 218 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
 219 {
 220         __inc_zone_state(page_zone(page), item);
 221 }
 222 EXPORT_SYMBOL(__inc_zone_page_state);
 223
 224 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 225 {
 226         struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
 227         s8 *p = pcp->vm_stat_diff + item;
 228
 229         (*p)--;
 230
 231         if (unlikely(*p < - pcp->stat_threshold)) {
 232                 int overstep = pcp->stat_threshold / 2;
 233
 234                 zone_page_state_add(*p - overstep, zone, item);
 235                 *p = overstep;
 236         }
 237 }
 238
 239 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
 240 {
 241         __dec_zone_state(page_zone(page), item);
 242 }
 243 EXPORT_SYMBOL(__dec_zone_page_state);
 244
 245 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 246 {
 247         unsigned long flags;
 248
 249         local_irq_save(flags);
 250         __inc_zone_state(zone, item);
 251         local_irq_restore(flags);
 252 }
 253
 254 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 255 {
 256         unsigned long flags;
 257         struct zone *zone;
 258
 259         zone = page_zone(page);
 260         local_irq_save(flags);
 261         __inc_zone_state(zone, item);
 262         local_irq_restore(flags);
 263 }
 264 EXPORT_SYMBOL(inc_zone_page_state);
 265
 266 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 267 {
 268         unsigned long flags;
 269
 270         local_irq_save(flags);
 271         __dec_zone_page_state(page, item);
 272         local_irq_restore(flags);
 273 }
 274 EXPORT_SYMBOL(dec_zone_page_state);
 275
 276 /*
 277  * Update the zone counters for one cpu.
 278  *
 279  * The cpu specified must be either the current cpu or a processor that
 280  * is not online. If it is the current cpu then the execution thread must
 281  * be pinned to the current cpu.
 282  *
 283  * Note that refresh_cpu_vm_stats strives to only access
 284  * node local memory. The per cpu pagesets on remote zones are placed
 285  * in the memory local to the processor using that pageset. So the
 286  * loop over all zones will access a series of cachelines local to
 287  * the processor.
 288  *
 289  * The call to zone_page_state_add updates the cachelines with the
 290  * statistics in the remote zone struct as well as the global cachelines
 291  * with the global counters. These could cause remote node cache line
 292  * bouncing and will have to be only done when necessary.
 293  */
 294 void refresh_cpu_vm_stats(int cpu)
 295 {
 296         struct zone *zone;
 297         int i;
 298         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
 299
 300         for_each_populated_zone(zone) {
 301                 struct per_cpu_pageset *p;
 302
 303                 p = zone_pcp(zone, cpu);
 304
 305                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 306                         if (p->vm_stat_diff[i]) {
 307                                 unsigned long flags;
 308                                 int v;
 309
 310                                 local_irq_save(flags);
 311                                 v = p->vm_stat_diff[i];
 312                                 p->vm_stat_diff[i] = 0;
 313                                 local_irq_restore(flags);
 314                                 atomic_long_add(v, &zone->vm_stat[i]);
 315                                 global_diff[i] += v;
 316 #ifdef CONFIG_NUMA
 317                                 /* 3 seconds idle till flush */
 318                                 p->expire = 3;
 319 #endif
 320                         }
 321                 cond_resched();
 322 #ifdef CONFIG_NUMA
 323                 /*
 324                  * Deal with draining the remote pageset of this
 325                  * processor
 326                  *
 327                  * Check if there are pages remaining in this pageset
 328                  * if not then there is nothing to expire.
 329                  */
 330                 if (!p->expire || !p->pcp.count)
 331                         continue;
 332
 333                 /*
 334                  * We never drain zones local to this processor.
 335                  */
 336                 if (zone_to_nid(zone) == numa_node_id()) {
 337                         p->expire = 0;
 338                         continue;
 339                 }
 340
 341                 p->expire--;
 342                 if (p->expire)
 343                         continue;
 344
 345                 if (p->pcp.count)
 346                         drain_zone_pages(zone, &p->pcp);
 347 #endif
 348         }
 349
 350         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 351                 if (global_diff[i])
 352                         atomic_long_add(global_diff[i], &vm_stat[i]);
 353 }
 354
 355 #endif
 356
 357 #ifdef CONFIG_NUMA
 358 /*
 359  * zonelist = the list of zones passed to the allocator
 360  * z        = the zone from which the allocation occurred.
 361  *
 362  * Must be called with interrupts disabled.
 363  */
 364 void zone_statistics(struct zone *preferred_zone, struct zone *z)
 365 {
 366         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
 367                 __inc_zone_state(z, NUMA_HIT);
 368         } else {
 369                 __inc_zone_state(z, NUMA_MISS);
 370                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
 371         }
 372         if (z->node == numa_node_id())
 373                 __inc_zone_state(z, NUMA_LOCAL);
 374         else
 375                 __inc_zone_state(z, NUMA_OTHER);
 376 }
 377 #endif
 378
 379 #ifdef CONFIG_PROC_FS
 380 #include <linux/proc_fs.h>
 381 #include <linux/seq_file.h>
 382
 383 static char * const migratetype_names[MIGRATE_TYPES] = {
 384         "Unmovable",
 385         "Reclaimable",
 386         "Movable",
 387         "Reserve",
 388         "Isolate",
 389 };
 390
 391 static void *frag_start(struct seq_file *m, loff_t *pos)
 392 {
 393         pg_data_t *pgdat;
 394         loff_t node = *pos;
 395         for (pgdat = first_online_pgdat();
 396              pgdat && node;
 397              pgdat = next_online_pgdat(pgdat))
 398                 --node;
 399
 400         return pgdat;
 401 }
 402
 403 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
 404 {
 405         pg_data_t *pgdat = (pg_data_t *)arg;
 406
 407         (*pos)++;
 408         return next_online_pgdat(pgdat);
 409 }
 410
 411 static void frag_stop(struct seq_file *m, void *arg)
 412 {
 413 }
 414
 415 /* Walk all the zones in a node and print using a callback */
 416 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 417                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 418 {
 419         struct zone *zone;
 420         struct zone *node_zones = pgdat->node_zones;
 421         unsigned long flags;
 422
 423         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
 424                 if (!populated_zone(zone))
 425                         continue;
 426
 427                 spin_lock_irqsave(&zone->lock, flags);
 428                 print(m, pgdat, zone);
 429                 spin_unlock_irqrestore(&zone->lock, flags);
 430         }
 431 }
 432
 433 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
 434                                                 struct zone *zone)
 435 {
 436         int order;
 437
 438         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 439         for (order = 0; order < MAX_ORDER; ++order)
 440                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
 441         seq_putc(m, '\n');
 442 }
 443
 444 /*
 445  * This walks the free areas for each zone.
 446  */
 447 static int frag_show(struct seq_file *m, void *arg)
 448 {
 449         pg_data_t *pgdat = (pg_data_t *)arg;
 450         walk_zones_in_node(m, pgdat, frag_show_print);
 451         return 0;
 452 }
 453
 454 static void pagetypeinfo_showfree_print(struct seq_file *m,
 455                                         pg_data_t *pgdat, struct zone *zone)
 456 {
 457         int order, mtype;
 458
 459         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
 460                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
 461                                         pgdat->node_id,
 462                                         zone->name,
 463                                         migratetype_names[mtype]);
 464                 for (order = 0; order < MAX_ORDER; ++order) {
 465                         unsigned long freecount = 0;
 466                         struct free_area *area;
 467                         struct list_head *curr;
 468
 469                         area = &(zone->free_area[order]);
 470
 471                         list_for_each(curr, &area->free_list[mtype])
 472                                 freecount++;
 473                         seq_printf(m, "%6lu ", freecount);
 474                 }
 475                 seq_putc(m, '\n');
 476         }
 477 }
 478
 479 /* Print out the free pages at each order for each migatetype */
 480 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
 481 {
 482         int order;
 483         pg_data_t *pgdat = (pg_data_t *)arg;
 484
 485         /* Print header */
 486         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
 487         for (order = 0; order < MAX_ORDER; ++order)
 488                 seq_printf(m, "%6d ", order);
 489         seq_putc(m, '\n');
 490
 491         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
 492
 493         return 0;
 494 }
 495
 496 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 497                                         pg_data_t *pgdat, struct zone *zone)
 498 {
 499         int mtype;
 500         unsigned long pfn;
 501         unsigned long start_pfn = zone->zone_start_pfn;
 502         unsigned long end_pfn = start_pfn + zone->spanned_pages;
 503         unsigned long count[MIGRATE_TYPES] = { 0, };
 504
 505         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
 506                 struct page *page;
 507
 508                 if (!pfn_valid(pfn))
 509                         continue;
 510
 511                 page = pfn_to_page(pfn);
 512
 513                 /* Watch for unexpected holes punched in the memmap */
 514                 if (!memmap_valid_within(pfn, page, zone))
 515                         continue;
 516
 517                 mtype = get_pageblock_migratetype(page);
 518
 519                 if (mtype < MIGRATE_TYPES)
 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 static 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 static int fragmentation_open(struct inode *inode, struct file *file)
 574 {
 575         return seq_open(file, &fragmentation_op);
 576 }
 577
 578 static const struct file_operations fragmentation_file_operations = {
 579         .open           = fragmentation_open,
 580         .read           = seq_read,
 581         .llseek         = seq_lseek,
 582         .release        = seq_release,
 583 };
 584
 585 static const struct seq_operations pagetypeinfo_op = {
 586         .start  = frag_start,
 587         .next   = frag_next,
 588         .stop   = frag_stop,
 589         .show   = pagetypeinfo_show,
 590 };
 591
 592 static int pagetypeinfo_open(struct inode *inode, struct file *file)
 593 {
 594         return seq_open(file, &pagetypeinfo_op);
 595 }
 596
 597 static const struct file_operations pagetypeinfo_file_ops = {
 598         .open           = pagetypeinfo_open,
 599         .read           = seq_read,
 600         .llseek         = seq_lseek,
 601         .release        = seq_release,
 602 };
 603
 604 #ifdef CONFIG_ZONE_DMA
 605 #define TEXT_FOR_DMA(xx) xx "_dma",
 606 #else
 607 #define TEXT_FOR_DMA(xx)
 608 #endif
 609
 610 #ifdef CONFIG_ZONE_DMA32
 611 #define TEXT_FOR_DMA32(xx) xx "_dma32",
 612 #else
 613 #define TEXT_FOR_DMA32(xx)
 614 #endif
 615
 616 #ifdef CONFIG_HIGHMEM
 617 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
 618 #else
 619 #define TEXT_FOR_HIGHMEM(xx)
 620 #endif
 621
 622 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
 623                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
 624
 625 static const char * const vmstat_text[] = {
 626         /* Zoned VM counters */
 627         "nr_free_pages",
 628         "nr_inactive_anon",
 629         "nr_active_anon",
 630         "nr_inactive_file",
 631         "nr_active_file",
 632         "nr_unevictable",
 633         "nr_mlock",
 634         "nr_anon_pages",
 635         "nr_mapped",
 636         "nr_file_pages",
 637         "nr_dirty",
 638         "nr_writeback",
 639         "nr_slab_reclaimable",
 640         "nr_slab_unreclaimable",
 641         "nr_page_table_pages",
 642         "nr_kernel_stack",
 643         "nr_unstable",
 644         "nr_bounce",
 645         "nr_vmscan_write",
 646         "nr_writeback_temp",
 647         "nr_isolated_anon",
 648         "nr_isolated_file",
 649         "nr_shmem",
 650 #ifdef CONFIG_NUMA
 651         "numa_hit",
 652         "numa_miss",
 653         "numa_foreign",
 654         "numa_interleave",
 655         "numa_local",
 656         "numa_other",
 657 #endif
 658
 659 #ifdef CONFIG_VM_EVENT_COUNTERS
 660         "pgpgin",
 661         "pgpgout",
 662         "pswpin",
 663         "pswpout",
 664
 665         TEXTS_FOR_ZONES("pgalloc")
 666
 667         "pgfree",
 668         "pgactivate",
 669         "pgdeactivate",
 670
 671         "pgfault",
 672         "pgmajfault",
 673
 674         TEXTS_FOR_ZONES("pgrefill")
 675         TEXTS_FOR_ZONES("pgsteal")
 676         TEXTS_FOR_ZONES("pgscan_kswapd")
 677         TEXTS_FOR_ZONES("pgscan_direct")
 678
 679 #ifdef CONFIG_NUMA
 680         "zone_reclaim_failed",
 681 #endif
 682         "pginodesteal",
 683         "slabs_scanned",
 684         "kswapd_steal",
 685         "kswapd_inodesteal",
 686         "pageoutrun",
 687         "allocstall",
 688
 689         "pgrotated",
 690 #ifdef CONFIG_HUGETLB_PAGE
 691         "htlb_buddy_alloc_success",
 692         "htlb_buddy_alloc_fail",
 693 #endif
 694         "unevictable_pgs_culled",
 695         "unevictable_pgs_scanned",
 696         "unevictable_pgs_rescued",
 697         "unevictable_pgs_mlocked",
 698         "unevictable_pgs_munlocked",
 699         "unevictable_pgs_cleared",
 700         "unevictable_pgs_stranded",
 701         "unevictable_pgs_mlockfreed",
 702 #endif
 703 };
 704
 705 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 706                                                         struct zone *zone)
 707 {
 708         int i;
 709         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
 710         seq_printf(m,
 711                    "\n  pages free     %lu"
 712                    "\n        min      %lu"
 713                    "\n        low      %lu"
 714                    "\n        high     %lu"
 715                    "\n        scanned  %lu"
 716                    "\n        spanned  %lu"
 717                    "\n        present  %lu",
 718                    zone_page_state(zone, NR_FREE_PAGES),
 719                    min_wmark_pages(zone),
 720                    low_wmark_pages(zone),
 721                    high_wmark_pages(zone),
 722                    zone->pages_scanned,
 723                    zone->spanned_pages,
 724                    zone->present_pages);
 725
 726         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 727                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
 728                                 zone_page_state(zone, i));
 729
 730         seq_printf(m,
 731                    "\n        protection: (%lu",
 732                    zone->lowmem_reserve[0]);
 733         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
 734                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
 735         seq_printf(m,
 736                    ")"
 737                    "\n  pagesets");
 738         for_each_online_cpu(i) {
 739                 struct per_cpu_pageset *pageset;
 740
 741                 pageset = zone_pcp(zone, i);
 742                 seq_printf(m,
 743                            "\n    cpu: %i"
 744                            "\n              count: %i"
 745                            "\n              high:  %i"
 746                            "\n              batch: %i",
 747                            i,
 748                            pageset->pcp.count,
 749                            pageset->pcp.high,
 750                            pageset->pcp.batch);
 751 #ifdef CONFIG_SMP
 752                 seq_printf(m, "\n  vm stats threshold: %d",
 753                                 pageset->stat_threshold);
 754 #endif
 755         }
 756         seq_printf(m,
 757                    "\n  all_unreclaimable: %u"
 758                    "\n  prev_priority:     %i"
 759                    "\n  start_pfn:         %lu"
 760                    "\n  inactive_ratio:    %u",
 761                            zone_is_all_unreclaimable(zone),
 762                    zone->prev_priority,
 763                    zone->zone_start_pfn,
 764                    zone->inactive_ratio);
 765         seq_putc(m, '\n');
 766 }
 767
 768 /*
 769  * Output information about zones in @pgdat.
 770  */
 771 static int zoneinfo_show(struct seq_file *m, void *arg)
 772 {
 773         pg_data_t *pgdat = (pg_data_t *)arg;
 774         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
 775         return 0;
 776 }
 777
 778 static const struct seq_operations zoneinfo_op = {
 779         .start  = frag_start, /* iterate over all zones. The same as in
 780                                * fragmentation. */
 781         .next   = frag_next,
 782         .stop   = frag_stop,
 783         .show   = zoneinfo_show,
 784 };
 785
 786 static int zoneinfo_open(struct inode *inode, struct file *file)
 787 {
 788         return seq_open(file, &zoneinfo_op);
 789 }
 790
 791 static const struct file_operations proc_zoneinfo_file_operations = {
 792         .open           = zoneinfo_open,
 793         .read           = seq_read,
 794         .llseek         = seq_lseek,
 795         .release        = seq_release,
 796 };
 797
 798 static void *vmstat_start(struct seq_file *m, loff_t *pos)
 799 {
 800         unsigned long *v;
 801 #ifdef CONFIG_VM_EVENT_COUNTERS
 802         unsigned long *e;
 803 #endif
 804         int i;
 805
 806         if (*pos >= ARRAY_SIZE(vmstat_text))
 807                 return NULL;
 808
 809 #ifdef CONFIG_VM_EVENT_COUNTERS
 810         v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
 811                         + sizeof(struct vm_event_state), GFP_KERNEL);
 812 #else
 813         v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
 814                         GFP_KERNEL);
 815 #endif
 816         m->private = v;
 817         if (!v)
 818                 return ERR_PTR(-ENOMEM);
 819         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 820                 v[i] = global_page_state(i);
 821 #ifdef CONFIG_VM_EVENT_COUNTERS
 822         e = v + NR_VM_ZONE_STAT_ITEMS;
 823         all_vm_events(e);
 824         e[PGPGIN] /= 2;         /* sectors -> kbytes */
 825         e[PGPGOUT] /= 2;
 826 #endif
 827         return v + *pos;
 828 }
 829
 830 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
 831 {
 832         (*pos)++;
 833         if (*pos >= ARRAY_SIZE(vmstat_text))
 834                 return NULL;
 835         return (unsigned long *)m->private + *pos;
 836 }
 837
 838 static int vmstat_show(struct seq_file *m, void *arg)
 839 {
 840         unsigned long *l = arg;
 841         unsigned long off = l - (unsigned long *)m->private;
 842
 843         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
 844         return 0;
 845 }
 846
 847 static void vmstat_stop(struct seq_file *m, void *arg)
 848 {
 849         kfree(m->private);
 850         m->private = NULL;
 851 }
 852
 853 static const struct seq_operations vmstat_op = {
 854         .start  = vmstat_start,
 855         .next   = vmstat_next,
 856         .stop   = vmstat_stop,
 857         .show   = vmstat_show,
 858 };
 859
 860 static int vmstat_open(struct inode *inode, struct file *file)
 861 {
 862         return seq_open(file, &vmstat_op);
 863 }
 864
 865 static const struct file_operations proc_vmstat_file_operations = {
 866         .open           = vmstat_open,
 867         .read           = seq_read,
 868         .llseek         = seq_lseek,
 869         .release        = seq_release,
 870 };
 871 #endif /* CONFIG_PROC_FS */
 872
 873 #ifdef CONFIG_SMP
 874 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
 875 int sysctl_stat_interval __read_mostly = HZ;
 876
 877 static void vmstat_update(struct work_struct *w)
 878 {
 879         refresh_cpu_vm_stats(smp_processor_id());
 880         schedule_delayed_work(&__get_cpu_var(vmstat_work),
 881                 round_jiffies_relative(sysctl_stat_interval));
 882 }
 883
 884 static void __cpuinit start_cpu_timer(int cpu)
 885 {
 886         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
 887
 888         INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
 889         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
 890 }
 891
 892 /*
 893  * Use the cpu notifier to insure that the thresholds are recalculated
 894  * when necessary.
 895  */
 896 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
 897                 unsigned long action,
 898                 void *hcpu)
 899 {
 900         long cpu = (long)hcpu;
 901
 902         switch (action) {
 903         case CPU_ONLINE:
 904         case CPU_ONLINE_FROZEN:
 905                 start_cpu_timer(cpu);
 906                 break;
 907         case CPU_DOWN_PREPARE:
 908         case CPU_DOWN_PREPARE_FROZEN:
 909                 cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
 910                 per_cpu(vmstat_work, cpu).work.func = NULL;
 911                 break;
 912         case CPU_DOWN_FAILED:
 913         case CPU_DOWN_FAILED_FROZEN:
 914                 start_cpu_timer(cpu);
 915                 break;
 916         case CPU_DEAD:
 917         case CPU_DEAD_FROZEN:
 918                 refresh_zone_stat_thresholds();
 919                 break;
 920         default:
 921                 break;
 922         }
 923         return NOTIFY_OK;
 924 }
 925
 926 static struct notifier_block __cpuinitdata vmstat_notifier =
 927         { &vmstat_cpuup_callback, NULL, 0 };
 928 #endif
 929
 930 static int __init setup_vmstat(void)
 931 {
 932 #ifdef CONFIG_SMP
 933         int cpu;
 934
 935         refresh_zone_stat_thresholds();
 936         register_cpu_notifier(&vmstat_notifier);
 937
 938         for_each_online_cpu(cpu)
 939                 start_cpu_timer(cpu);
 940 #endif
 941 #ifdef CONFIG_PROC_FS
 942         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
 943         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
 944         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
 945         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
 946 #endif
 947         return 0;
 948 }
 949 module_init(setup_vmstat)