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 #include <linux/math64.h>
  20 #include <linux/writeback.h>
  21 #include <linux/compaction.h>
  22
  23 #ifdef CONFIG_VM_EVENT_COUNTERS
  24 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
  25 EXPORT_PER_CPU_SYMBOL(vm_event_states);
  26
  27 static void sum_vm_events(unsigned long *ret)
  28 {
  29         int cpu;
  30         int i;
  31
  32         memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
  33
  34         for_each_online_cpu(cpu) {
  35                 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
  36
  37                 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
  38                         ret[i] += this->event[i];
  39         }
  40 }
  41
  42 /*
  43  * Accumulate the vm event counters across all CPUs.
  44  * The result is unavoidably approximate - it can change
  45  * during and after execution of this function.
  46 */
  47 void all_vm_events(unsigned long *ret)
  48 {
  49         get_online_cpus();
  50         sum_vm_events(ret);
  51         put_online_cpus();
  52 }
  53 EXPORT_SYMBOL_GPL(all_vm_events);
  54
  55 #ifdef CONFIG_HOTPLUG
  56 /*
  57  * Fold the foreign cpu events into our own.
  58  *
  59  * This is adding to the events on one processor
  60  * but keeps the global counts constant.
  61  */
  62 void vm_events_fold_cpu(int cpu)
  63 {
  64         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
  65         int i;
  66
  67         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
  68                 count_vm_events(i, fold_state->event[i]);
  69                 fold_state->event[i] = 0;
  70         }
  71 }
  72 #endif /* CONFIG_HOTPLUG */
  73
  74 #endif /* CONFIG_VM_EVENT_COUNTERS */
  75
  76 /*
  77  * Manage combined zone based / global counters
  78  *
  79  * vm_stat contains the global counters
  80  */
  81 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
  82 EXPORT_SYMBOL(vm_stat);
  83
  84 #ifdef CONFIG_SMP
  85
  86 int calculate_pressure_threshold(struct zone *zone)
  87 {
  88         int threshold;
  89         int watermark_distance;
  90
  91         /*
  92          * As vmstats are not up to date, there is drift between the estimated
  93          * and real values. For high thresholds and a high number of CPUs, it
  94          * is possible for the min watermark to be breached while the estimated
  95          * value looks fine. The pressure threshold is a reduced value such
  96          * that even the maximum amount of drift will not accidentally breach
  97          * the min watermark
  98          */
  99         watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
 100         threshold = max(1, (int)(watermark_distance / num_online_cpus()));
 101
 102         /*
 103          * Maximum threshold is 125
 104          */
 105         threshold = min(125, threshold);
 106
 107         return threshold;
 108 }
 109
 110 int calculate_normal_threshold(struct zone *zone)
 111 {
 112         int threshold;
 113         int mem;        /* memory in 128 MB units */
 114
 115         /*
 116          * The threshold scales with the number of processors and the amount
 117          * of memory per zone. More memory means that we can defer updates for
 118          * longer, more processors could lead to more contention.
 119          * fls() is used to have a cheap way of logarithmic scaling.
 120          *
 121          * Some sample thresholds:
 122          *
 123          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
 124          * ------------------------------------------------------------------
 125          * 8            1               1       0.9-1 GB        4
 126          * 16           2               2       0.9-1 GB        4
 127          * 20           2               2       1-2 GB          5
 128          * 24           2               2       2-4 GB          6
 129          * 28           2               2       4-8 GB          7
 130          * 32           2               2       8-16 GB         8
 131          * 4            2               2       <128M           1
 132          * 30           4               3       2-4 GB          5
 133          * 48           4               3       8-16 GB         8
 134          * 32           8               4       1-2 GB          4
 135          * 32           8               4       0.9-1GB         4
 136          * 10           16              5       <128M           1
 137          * 40           16              5       900M            4
 138          * 70           64              7       2-4 GB          5
 139          * 84           64              7       4-8 GB          6
 140          * 108          512             9       4-8 GB          6
 141          * 125          1024            10      8-16 GB         8
 142          * 125          1024            10      16-32 GB        9
 143          */
 144
 145         mem = zone->managed_pages >> (27 - PAGE_SHIFT);
 146
 147         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
 148
 149         /*
 150          * Maximum threshold is 125
 151          */
 152         threshold = min(125, threshold);
 153
 154         return threshold;
 155 }
 156
 157 /*
 158  * Refresh the thresholds for each zone.
 159  */
 160 void refresh_zone_stat_thresholds(void)
 161 {
 162         struct zone *zone;
 163         int cpu;
 164         int threshold;
 165
 166         for_each_populated_zone(zone) {
 167                 unsigned long max_drift, tolerate_drift;
 168
 169                 threshold = calculate_normal_threshold(zone);
 170
 171                 for_each_online_cpu(cpu)
 172                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 173                                                         = threshold;
 174
 175                 /*
 176                  * Only set percpu_drift_mark if there is a danger that
 177                  * NR_FREE_PAGES reports the low watermark is ok when in fact
 178                  * the min watermark could be breached by an allocation
 179                  */
 180                 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
 181                 max_drift = num_online_cpus() * threshold;
 182                 if (max_drift > tolerate_drift)
 183                         zone->percpu_drift_mark = high_wmark_pages(zone) +
 184                                         max_drift;
 185         }
 186 }
 187
 188 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
 189                                 int (*calculate_pressure)(struct zone *))
 190 {
 191         struct zone *zone;
 192         int cpu;
 193         int threshold;
 194         int i;
 195
 196         for (i = 0; i < pgdat->nr_zones; i++) {
 197                 zone = &pgdat->node_zones[i];
 198                 if (!zone->percpu_drift_mark)
 199                         continue;
 200
 201                 threshold = (*calculate_pressure)(zone);
 202                 for_each_possible_cpu(cpu)
 203                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 204                                                         = threshold;
 205         }
 206 }
 207
 208 /*
 209  * For use when we know that interrupts are disabled.
 210  */
 211 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 212                                 int delta)
 213 {
 214         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 215         s8 __percpu *p = pcp->vm_stat_diff + item;
 216         long x;
 217         long t;
 218
 219         x = delta + __this_cpu_read(*p);
 220
 221         t = __this_cpu_read(pcp->stat_threshold);
 222
 223         if (unlikely(x > t || x < -t)) {
 224                 zone_page_state_add(x, zone, item);
 225                 x = 0;
 226         }
 227         __this_cpu_write(*p, x);
 228 }
 229 EXPORT_SYMBOL(__mod_zone_page_state);
 230
 231 /*
 232  * Optimized increment and decrement functions.
 233  *
 234  * These are only for a single page and therefore can take a struct page *
 235  * argument instead of struct zone *. This allows the inclusion of the code
 236  * generated for page_zone(page) into the optimized functions.
 237  *
 238  * No overflow check is necessary and therefore the differential can be
 239  * incremented or decremented in place which may allow the compilers to
 240  * generate better code.
 241  * The increment or decrement is known and therefore one boundary check can
 242  * be omitted.
 243  *
 244  * NOTE: These functions are very performance sensitive. Change only
 245  * with care.
 246  *
 247  * Some processors have inc/dec instructions that are atomic vs an interrupt.
 248  * However, the code must first determine the differential location in a zone
 249  * based on the processor number and then inc/dec the counter. There is no
 250  * guarantee without disabling preemption that the processor will not change
 251  * in between and therefore the atomicity vs. interrupt cannot be exploited
 252  * in a useful way here.
 253  */
 254 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 255 {
 256         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 257         s8 __percpu *p = pcp->vm_stat_diff + item;
 258         s8 v, t;
 259
 260         v = __this_cpu_inc_return(*p);
 261         t = __this_cpu_read(pcp->stat_threshold);
 262         if (unlikely(v > t)) {
 263                 s8 overstep = t >> 1;
 264
 265                 zone_page_state_add(v + overstep, zone, item);
 266                 __this_cpu_write(*p, -overstep);
 267         }
 268 }
 269
 270 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
 271 {
 272         __inc_zone_state(page_zone(page), item);
 273 }
 274 EXPORT_SYMBOL(__inc_zone_page_state);
 275
 276 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 277 {
 278         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 279         s8 __percpu *p = pcp->vm_stat_diff + item;
 280         s8 v, t;
 281
 282         v = __this_cpu_dec_return(*p);
 283         t = __this_cpu_read(pcp->stat_threshold);
 284         if (unlikely(v < - t)) {
 285                 s8 overstep = t >> 1;
 286
 287                 zone_page_state_add(v - overstep, zone, item);
 288                 __this_cpu_write(*p, overstep);
 289         }
 290 }
 291
 292 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
 293 {
 294         __dec_zone_state(page_zone(page), item);
 295 }
 296 EXPORT_SYMBOL(__dec_zone_page_state);
 297
 298 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
 299 /*
 300  * If we have cmpxchg_local support then we do not need to incur the overhead
 301  * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
 302  *
 303  * mod_state() modifies the zone counter state through atomic per cpu
 304  * operations.
 305  *
 306  * Overstep mode specifies how overstep should handled:
 307  *     0       No overstepping
 308  *     1       Overstepping half of threshold
 309  *     -1      Overstepping minus half of threshold
 310 */
 311 static inline void mod_state(struct zone *zone,
 312        enum zone_stat_item item, int delta, int overstep_mode)
 313 {
 314         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 315         s8 __percpu *p = pcp->vm_stat_diff + item;
 316         long o, n, t, z;
 317
 318         do {
 319                 z = 0;  /* overflow to zone counters */
 320
 321                 /*
 322                  * The fetching of the stat_threshold is racy. We may apply
 323                  * a counter threshold to the wrong the cpu if we get
 324                  * rescheduled while executing here. However, the next
 325                  * counter update will apply the threshold again and
 326                  * therefore bring the counter under the threshold again.
 327                  *
 328                  * Most of the time the thresholds are the same anyways
 329                  * for all cpus in a zone.
 330                  */
 331                 t = this_cpu_read(pcp->stat_threshold);
 332
 333                 o = this_cpu_read(*p);
 334                 n = delta + o;
 335
 336                 if (n > t || n < -t) {
 337                         int os = overstep_mode * (t >> 1) ;
 338
 339                         /* Overflow must be added to zone counters */
 340                         z = n + os;
 341                         n = -os;
 342                 }
 343         } while (this_cpu_cmpxchg(*p, o, n) != o);
 344
 345         if (z)
 346                 zone_page_state_add(z, zone, item);
 347 }
 348
 349 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 350                                         int delta)
 351 {
 352         mod_state(zone, item, delta, 0);
 353 }
 354 EXPORT_SYMBOL(mod_zone_page_state);
 355
 356 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 357 {
 358         mod_state(zone, item, 1, 1);
 359 }
 360
 361 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 362 {
 363         mod_state(page_zone(page), item, 1, 1);
 364 }
 365 EXPORT_SYMBOL(inc_zone_page_state);
 366
 367 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 368 {
 369         mod_state(page_zone(page), item, -1, -1);
 370 }
 371 EXPORT_SYMBOL(dec_zone_page_state);
 372 #else
 373 /*
 374  * Use interrupt disable to serialize counter updates
 375  */
 376 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 377                                         int delta)
 378 {
 379         unsigned long flags;
 380
 381         local_irq_save(flags);
 382         __mod_zone_page_state(zone, item, delta);
 383         local_irq_restore(flags);
 384 }
 385 EXPORT_SYMBOL(mod_zone_page_state);
 386
 387 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 388 {
 389         unsigned long flags;
 390
 391         local_irq_save(flags);
 392         __inc_zone_state(zone, item);
 393         local_irq_restore(flags);
 394 }
 395
 396 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 397 {
 398         unsigned long flags;
 399         struct zone *zone;
 400
 401         zone = page_zone(page);
 402         local_irq_save(flags);
 403         __inc_zone_state(zone, item);
 404         local_irq_restore(flags);
 405 }
 406 EXPORT_SYMBOL(inc_zone_page_state);
 407
 408 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 409 {
 410         unsigned long flags;
 411
 412         local_irq_save(flags);
 413         __dec_zone_page_state(page, item);
 414         local_irq_restore(flags);
 415 }
 416 EXPORT_SYMBOL(dec_zone_page_state);
 417 #endif
 418
 419 /*
 420  * Update the zone counters for one cpu.
 421  *
 422  * The cpu specified must be either the current cpu or a processor that
 423  * is not online. If it is the current cpu then the execution thread must
 424  * be pinned to the current cpu.
 425  *
 426  * Note that refresh_cpu_vm_stats strives to only access
 427  * node local memory. The per cpu pagesets on remote zones are placed
 428  * in the memory local to the processor using that pageset. So the
 429  * loop over all zones will access a series of cachelines local to
 430  * the processor.
 431  *
 432  * The call to zone_page_state_add updates the cachelines with the
 433  * statistics in the remote zone struct as well as the global cachelines
 434  * with the global counters. These could cause remote node cache line
 435  * bouncing and will have to be only done when necessary.
 436  */
 437 void refresh_cpu_vm_stats(int cpu)
 438 {
 439         struct zone *zone;
 440         int i;
 441         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
 442
 443         for_each_populated_zone(zone) {
 444                 struct per_cpu_pageset *p;
 445
 446                 p = per_cpu_ptr(zone->pageset, cpu);
 447
 448                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 449                         if (p->vm_stat_diff[i]) {
 450                                 unsigned long flags;
 451                                 int v;
 452
 453                                 local_irq_save(flags);
 454                                 v = p->vm_stat_diff[i];
 455                                 p->vm_stat_diff[i] = 0;
 456                                 local_irq_restore(flags);
 457                                 atomic_long_add(v, &zone->vm_stat[i]);
 458                                 global_diff[i] += v;
 459 #ifdef CONFIG_NUMA
 460                                 /* 3 seconds idle till flush */
 461                                 p->expire = 3;
 462 #endif
 463                         }
 464                 cond_resched();
 465 #ifdef CONFIG_NUMA
 466                 /*
 467                  * Deal with draining the remote pageset of this
 468                  * processor
 469                  *
 470                  * Check if there are pages remaining in this pageset
 471                  * if not then there is nothing to expire.
 472                  */
 473                 if (!p->expire || !p->pcp.count)
 474                         continue;
 475
 476                 /*
 477                  * We never drain zones local to this processor.
 478                  */
 479                 if (zone_to_nid(zone) == numa_node_id()) {
 480                         p->expire = 0;
 481                         continue;
 482                 }
 483
 484                 p->expire--;
 485                 if (p->expire)
 486                         continue;
 487
 488                 if (p->pcp.count)
 489                         drain_zone_pages(zone, &p->pcp);
 490 #endif
 491         }
 492
 493         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 494                 if (global_diff[i])
 495                         atomic_long_add(global_diff[i], &vm_stat[i]);
 496 }
 497
 498 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
 499 {
 500         int i;
 501
 502         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 503                 if (pset->vm_stat_diff[i]) {
 504                         int v = pset->vm_stat_diff[i];
 505                         pset->vm_stat_diff[i] = 0;
 506                         atomic_long_add(v, &zone->vm_stat[i]);
 507                         atomic_long_add(v, &vm_stat[i]);
 508                 }
 509 }
 510 #endif
 511
 512 #ifdef CONFIG_NUMA
 513 /*
 514  * zonelist = the list of zones passed to the allocator
 515  * z        = the zone from which the allocation occurred.
 516  *
 517  * Must be called with interrupts disabled.
 518  *
 519  * When __GFP_OTHER_NODE is set assume the node of the preferred
 520  * zone is the local node. This is useful for daemons who allocate
 521  * memory on behalf of other processes.
 522  */
 523 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
 524 {
 525         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
 526                 __inc_zone_state(z, NUMA_HIT);
 527         } else {
 528                 __inc_zone_state(z, NUMA_MISS);
 529                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
 530         }
 531         if (z->node == ((flags & __GFP_OTHER_NODE) ?
 532                         preferred_zone->node : numa_node_id()))
 533                 __inc_zone_state(z, NUMA_LOCAL);
 534         else
 535                 __inc_zone_state(z, NUMA_OTHER);
 536 }
 537 #endif
 538
 539 #ifdef CONFIG_COMPACTION
 540
 541 struct contig_page_info {
 542         unsigned long free_pages;
 543         unsigned long free_blocks_total;
 544         unsigned long free_blocks_suitable;
 545 };
 546
 547 /*
 548  * Calculate the number of free pages in a zone, how many contiguous
 549  * pages are free and how many are large enough to satisfy an allocation of
 550  * the target size. Note that this function makes no attempt to estimate
 551  * how many suitable free blocks there *might* be if MOVABLE pages were
 552  * migrated. Calculating that is possible, but expensive and can be
 553  * figured out from userspace
 554  */
 555 static void fill_contig_page_info(struct zone *zone,
 556                                 unsigned int suitable_order,
 557                                 struct contig_page_info *info)
 558 {
 559         unsigned int order;
 560
 561         info->free_pages = 0;
 562         info->free_blocks_total = 0;
 563         info->free_blocks_suitable = 0;
 564
 565         for (order = 0; order < MAX_ORDER; order++) {
 566                 unsigned long blocks;
 567
 568                 /* Count number of free blocks */
 569                 blocks = zone->free_area[order].nr_free;
 570                 info->free_blocks_total += blocks;
 571
 572                 /* Count free base pages */
 573                 info->free_pages += blocks << order;
 574
 575                 /* Count the suitable free blocks */
 576                 if (order >= suitable_order)
 577                         info->free_blocks_suitable += blocks <<
 578                                                 (order - suitable_order);
 579         }
 580 }
 581
 582 /*
 583  * A fragmentation index only makes sense if an allocation of a requested
 584  * size would fail. If that is true, the fragmentation index indicates
 585  * whether external fragmentation or a lack of memory was the problem.
 586  * The value can be used to determine if page reclaim or compaction
 587  * should be used
 588  */
 589 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
 590 {
 591         unsigned long requested = 1UL << order;
 592
 593         if (!info->free_blocks_total)
 594                 return 0;
 595
 596         /* Fragmentation index only makes sense when a request would fail */
 597         if (info->free_blocks_suitable)
 598                 return -1000;
 599
 600         /*
 601          * Index is between 0 and 1 so return within 3 decimal places
 602          *
 603          * 0 => allocation would fail due to lack of memory
 604          * 1 => allocation would fail due to fragmentation
 605          */
 606         return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
 607 }
 608
 609 /* Same as __fragmentation index but allocs contig_page_info on stack */
 610 int fragmentation_index(struct zone *zone, unsigned int order)
 611 {
 612         struct contig_page_info info;
 613
 614         fill_contig_page_info(zone, order, &info);
 615         return __fragmentation_index(order, &info);
 616 }
 617 #endif
 618
 619 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
 620 #include <linux/proc_fs.h>
 621 #include <linux/seq_file.h>
 622
 623 static char * const migratetype_names[MIGRATE_TYPES] = {
 624         "Unmovable",
 625         "Reclaimable",
 626         "Movable",
 627         "Reserve",
 628 #ifdef CONFIG_CMA
 629         "CMA",
 630 #endif
 631 #ifdef CONFIG_MEMORY_ISOLATION
 632         "Isolate",
 633 #endif
 634 };
 635
 636 static void *frag_start(struct seq_file *m, loff_t *pos)
 637 {
 638         pg_data_t *pgdat;
 639         loff_t node = *pos;
 640         for (pgdat = first_online_pgdat();
 641              pgdat && node;
 642              pgdat = next_online_pgdat(pgdat))
 643                 --node;
 644
 645         return pgdat;
 646 }
 647
 648 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
 649 {
 650         pg_data_t *pgdat = (pg_data_t *)arg;
 651
 652         (*pos)++;
 653         return next_online_pgdat(pgdat);
 654 }
 655
 656 static void frag_stop(struct seq_file *m, void *arg)
 657 {
 658 }
 659
 660 /* Walk all the zones in a node and print using a callback */
 661 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 662                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 663 {
 664         struct zone *zone;
 665         struct zone *node_zones = pgdat->node_zones;
 666         unsigned long flags;
 667
 668         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
 669                 if (!populated_zone(zone))
 670                         continue;
 671
 672                 spin_lock_irqsave(&zone->lock, flags);
 673                 print(m, pgdat, zone);
 674                 spin_unlock_irqrestore(&zone->lock, flags);
 675         }
 676 }
 677 #endif
 678
 679 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
 680 #ifdef CONFIG_ZONE_DMA
 681 #define TEXT_FOR_DMA(xx) xx "_dma",
 682 #else
 683 #define TEXT_FOR_DMA(xx)
 684 #endif
 685
 686 #ifdef CONFIG_ZONE_DMA32
 687 #define TEXT_FOR_DMA32(xx) xx "_dma32",
 688 #else
 689 #define TEXT_FOR_DMA32(xx)
 690 #endif
 691
 692 #ifdef CONFIG_HIGHMEM
 693 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
 694 #else
 695 #define TEXT_FOR_HIGHMEM(xx)
 696 #endif
 697
 698 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
 699                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
 700
 701 const char * const vmstat_text[] = {
 702         /* Zoned VM counters */
 703         "nr_free_pages",
 704         "nr_inactive_anon",
 705         "nr_active_anon",
 706         "nr_inactive_file",
 707         "nr_active_file",
 708         "nr_unevictable",
 709         "nr_mlock",
 710         "nr_anon_pages",
 711         "nr_mapped",
 712         "nr_file_pages",
 713         "nr_dirty",
 714         "nr_writeback",
 715         "nr_slab_reclaimable",
 716         "nr_slab_unreclaimable",
 717         "nr_page_table_pages",
 718         "nr_kernel_stack",
 719         "nr_unstable",
 720         "nr_bounce",
 721         "nr_vmscan_write",
 722         "nr_vmscan_immediate_reclaim",
 723         "nr_writeback_temp",
 724         "nr_isolated_anon",
 725         "nr_isolated_file",
 726         "nr_shmem",
 727         "nr_dirtied",
 728         "nr_written",
 729
 730 #ifdef CONFIG_NUMA
 731         "numa_hit",
 732         "numa_miss",
 733         "numa_foreign",
 734         "numa_interleave",
 735         "numa_local",
 736         "numa_other",
 737 #endif
 738         "nr_anon_transparent_hugepages",
 739         "nr_free_cma",
 740         "nr_dirty_threshold",
 741         "nr_dirty_background_threshold",
 742
 743 #ifdef CONFIG_VM_EVENT_COUNTERS
 744         "pgpgin",
 745         "pgpgout",
 746         "pswpin",
 747         "pswpout",
 748
 749         TEXTS_FOR_ZONES("pgalloc")
 750
 751         "pgfree",
 752         "pgactivate",
 753         "pgdeactivate",
 754
 755         "pgfault",
 756         "pgmajfault",
 757
 758         TEXTS_FOR_ZONES("pgrefill")
 759         TEXTS_FOR_ZONES("pgsteal_kswapd")
 760         TEXTS_FOR_ZONES("pgsteal_direct")
 761         TEXTS_FOR_ZONES("pgscan_kswapd")
 762         TEXTS_FOR_ZONES("pgscan_direct")
 763         "pgscan_direct_throttle",
 764
 765 #ifdef CONFIG_NUMA
 766         "zone_reclaim_failed",
 767 #endif
 768         "pginodesteal",
 769         "slabs_scanned",
 770         "kswapd_inodesteal",
 771         "kswapd_low_wmark_hit_quickly",
 772         "kswapd_high_wmark_hit_quickly",
 773         "pageoutrun",
 774         "allocstall",
 775
 776         "pgrotated",
 777
 778 #ifdef CONFIG_NUMA_BALANCING
 779         "numa_pte_updates",
 780         "numa_hint_faults",
 781         "numa_hint_faults_local",
 782         "numa_pages_migrated",
 783 #endif
 784 #ifdef CONFIG_MIGRATION
 785         "pgmigrate_success",
 786         "pgmigrate_fail",
 787 #endif
 788 #ifdef CONFIG_COMPACTION
 789         "compact_migrate_scanned",
 790         "compact_free_scanned",
 791         "compact_isolated",
 792         "compact_stall",
 793         "compact_fail",
 794         "compact_success",
 795 #endif
 796
 797 #ifdef CONFIG_HUGETLB_PAGE
 798         "htlb_buddy_alloc_success",
 799         "htlb_buddy_alloc_fail",
 800 #endif
 801         "unevictable_pgs_culled",
 802         "unevictable_pgs_scanned",
 803         "unevictable_pgs_rescued",
 804         "unevictable_pgs_mlocked",
 805         "unevictable_pgs_munlocked",
 806         "unevictable_pgs_cleared",
 807         "unevictable_pgs_stranded",
 808
 809 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 810         "thp_fault_alloc",
 811         "thp_fault_fallback",
 812         "thp_collapse_alloc",
 813         "thp_collapse_alloc_failed",
 814         "thp_split",
 815         "thp_zero_page_alloc",
 816         "thp_zero_page_alloc_failed",
 817 #endif
 818
 819 #endif /* CONFIG_VM_EVENTS_COUNTERS */
 820 };
 821 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
 822
 823
 824 #ifdef CONFIG_PROC_FS
 825 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
 826                                                 struct zone *zone)
 827 {
 828         int order;
 829
 830         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 831         for (order = 0; order < MAX_ORDER; ++order)
 832                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
 833         seq_putc(m, '\n');
 834 }
 835
 836 /*
 837  * This walks the free areas for each zone.
 838  */
 839 static int frag_show(struct seq_file *m, void *arg)
 840 {
 841         pg_data_t *pgdat = (pg_data_t *)arg;
 842         walk_zones_in_node(m, pgdat, frag_show_print);
 843         return 0;
 844 }
 845
 846 static void pagetypeinfo_showfree_print(struct seq_file *m,
 847                                         pg_data_t *pgdat, struct zone *zone)
 848 {
 849         int order, mtype;
 850
 851         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
 852                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
 853                                         pgdat->node_id,
 854                                         zone->name,
 855                                         migratetype_names[mtype]);
 856                 for (order = 0; order < MAX_ORDER; ++order) {
 857                         unsigned long freecount = 0;
 858                         struct free_area *area;
 859                         struct list_head *curr;
 860
 861                         area = &(zone->free_area[order]);
 862
 863                         list_for_each(curr, &area->free_list[mtype])
 864                                 freecount++;
 865                         seq_printf(m, "%6lu ", freecount);
 866                 }
 867                 seq_putc(m, '\n');
 868         }
 869 }
 870
 871 /* Print out the free pages at each order for each migatetype */
 872 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
 873 {
 874         int order;
 875         pg_data_t *pgdat = (pg_data_t *)arg;
 876
 877         /* Print header */
 878         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
 879         for (order = 0; order < MAX_ORDER; ++order)
 880                 seq_printf(m, "%6d ", order);
 881         seq_putc(m, '\n');
 882
 883         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
 884
 885         return 0;
 886 }
 887
 888 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 889                                         pg_data_t *pgdat, struct zone *zone)
 890 {
 891         int mtype;
 892         unsigned long pfn;
 893         unsigned long start_pfn = zone->zone_start_pfn;
 894         unsigned long end_pfn = zone_end_pfn(zone);
 895         unsigned long count[MIGRATE_TYPES] = { 0, };
 896
 897         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
 898                 struct page *page;
 899
 900                 if (!pfn_valid(pfn))
 901                         continue;
 902
 903                 page = pfn_to_page(pfn);
 904
 905                 /* Watch for unexpected holes punched in the memmap */
 906                 if (!memmap_valid_within(pfn, page, zone))
 907                         continue;
 908
 909                 mtype = get_pageblock_migratetype(page);
 910
 911                 if (mtype < MIGRATE_TYPES)
 912                         count[mtype]++;
 913         }
 914
 915         /* Print counts */
 916         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 917         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 918                 seq_printf(m, "%12lu ", count[mtype]);
 919         seq_putc(m, '\n');
 920 }
 921
 922 /* Print out the free pages at each order for each migratetype */
 923 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
 924 {
 925         int mtype;
 926         pg_data_t *pgdat = (pg_data_t *)arg;
 927
 928         seq_printf(m, "\n%-23s", "Number of blocks type ");
 929         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 930                 seq_printf(m, "%12s ", migratetype_names[mtype]);
 931         seq_putc(m, '\n');
 932         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
 933
 934         return 0;
 935 }
 936
 937 /*
 938  * This prints out statistics in relation to grouping pages by mobility.
 939  * It is expensive to collect so do not constantly read the file.
 940  */
 941 static int pagetypeinfo_show(struct seq_file *m, void *arg)
 942 {
 943         pg_data_t *pgdat = (pg_data_t *)arg;
 944
 945         /* check memoryless node */
 946         if (!node_state(pgdat->node_id, N_MEMORY))
 947                 return 0;
 948
 949         seq_printf(m, "Page block order: %d\n", pageblock_order);
 950         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
 951         seq_putc(m, '\n');
 952         pagetypeinfo_showfree(m, pgdat);
 953         pagetypeinfo_showblockcount(m, pgdat);
 954
 955         return 0;
 956 }
 957
 958 static const struct seq_operations fragmentation_op = {
 959         .start  = frag_start,
 960         .next   = frag_next,
 961         .stop   = frag_stop,
 962         .show   = frag_show,
 963 };
 964
 965 static int fragmentation_open(struct inode *inode, struct file *file)
 966 {
 967         return seq_open(file, &fragmentation_op);
 968 }
 969
 970 static const struct file_operations fragmentation_file_operations = {
 971         .open           = fragmentation_open,
 972         .read           = seq_read,
 973         .llseek         = seq_lseek,
 974         .release        = seq_release,
 975 };
 976
 977 static const struct seq_operations pagetypeinfo_op = {
 978         .start  = frag_start,
 979         .next   = frag_next,
 980         .stop   = frag_stop,
 981         .show   = pagetypeinfo_show,
 982 };
 983
 984 static int pagetypeinfo_open(struct inode *inode, struct file *file)
 985 {
 986         return seq_open(file, &pagetypeinfo_op);
 987 }
 988
 989 static const struct file_operations pagetypeinfo_file_ops = {
 990         .open           = pagetypeinfo_open,
 991         .read           = seq_read,
 992         .llseek         = seq_lseek,
 993         .release        = seq_release,
 994 };
 995
 996 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 997                                                         struct zone *zone)
 998 {
 999         int i;
1000         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1001         seq_printf(m,
1002                    "\n  pages free     %lu"
1003                    "\n        min      %lu"
1004                    "\n        low      %lu"
1005                    "\n        high     %lu"
1006                    "\n        scanned  %lu"
1007                    "\n        spanned  %lu"
1008                    "\n        present  %lu"
1009                    "\n        managed  %lu",
1010                    zone_page_state(zone, NR_FREE_PAGES),
1011                    min_wmark_pages(zone),
1012                    low_wmark_pages(zone),
1013                    high_wmark_pages(zone),
1014                    zone->pages_scanned,
1015                    zone->spanned_pages,
1016                    zone->present_pages,
1017                    zone->managed_pages);
1018
1019         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1020                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
1021                                 zone_page_state(zone, i));
1022
1023         seq_printf(m,
1024                    "\n        protection: (%lu",
1025                    zone->lowmem_reserve[0]);
1026         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1027                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
1028         seq_printf(m,
1029                    ")"
1030                    "\n  pagesets");
1031         for_each_online_cpu(i) {
1032                 struct per_cpu_pageset *pageset;
1033
1034                 pageset = per_cpu_ptr(zone->pageset, i);
1035                 seq_printf(m,
1036                            "\n    cpu: %i"
1037                            "\n              count: %i"
1038                            "\n              high:  %i"
1039                            "\n              batch: %i",
1040                            i,
1041                            pageset->pcp.count,
1042                            pageset->pcp.high,
1043                            pageset->pcp.batch);
1044 #ifdef CONFIG_SMP
1045                 seq_printf(m, "\n  vm stats threshold: %d",
1046                                 pageset->stat_threshold);
1047 #endif
1048         }
1049         seq_printf(m,
1050                    "\n  all_unreclaimable: %u"
1051                    "\n  start_pfn:         %lu"
1052                    "\n  inactive_ratio:    %u",
1053                    zone->all_unreclaimable,
1054                    zone->zone_start_pfn,
1055                    zone->inactive_ratio);
1056         seq_putc(m, '\n');
1057 }
1058
1059 /*
1060  * Output information about zones in @pgdat.
1061  */
1062 static int zoneinfo_show(struct seq_file *m, void *arg)
1063 {
1064         pg_data_t *pgdat = (pg_data_t *)arg;
1065         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1066         return 0;
1067 }
1068
1069 static const struct seq_operations zoneinfo_op = {
1070         .start  = frag_start, /* iterate over all zones. The same as in
1071                                * fragmentation. */
1072         .next   = frag_next,
1073         .stop   = frag_stop,
1074         .show   = zoneinfo_show,
1075 };
1076
1077 static int zoneinfo_open(struct inode *inode, struct file *file)
1078 {
1079         return seq_open(file, &zoneinfo_op);
1080 }
1081
1082 static const struct file_operations proc_zoneinfo_file_operations = {
1083         .open           = zoneinfo_open,
1084         .read           = seq_read,
1085         .llseek         = seq_lseek,
1086         .release        = seq_release,
1087 };
1088
1089 enum writeback_stat_item {
1090         NR_DIRTY_THRESHOLD,
1091         NR_DIRTY_BG_THRESHOLD,
1092         NR_VM_WRITEBACK_STAT_ITEMS,
1093 };
1094
1095 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1096 {
1097         unsigned long *v;
1098         int i, stat_items_size;
1099
1100         if (*pos >= ARRAY_SIZE(vmstat_text))
1101                 return NULL;
1102         stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1103                           NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1104
1105 #ifdef CONFIG_VM_EVENT_COUNTERS
1106         stat_items_size += sizeof(struct vm_event_state);
1107 #endif
1108
1109         v = kmalloc(stat_items_size, GFP_KERNEL);
1110         m->private = v;
1111         if (!v)
1112                 return ERR_PTR(-ENOMEM);
1113         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1114                 v[i] = global_page_state(i);
1115         v += NR_VM_ZONE_STAT_ITEMS;
1116
1117         global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1118                             v + NR_DIRTY_THRESHOLD);
1119         v += NR_VM_WRITEBACK_STAT_ITEMS;
1120
1121 #ifdef CONFIG_VM_EVENT_COUNTERS
1122         all_vm_events(v);
1123         v[PGPGIN] /= 2;         /* sectors -> kbytes */
1124         v[PGPGOUT] /= 2;
1125 #endif
1126         return (unsigned long *)m->private + *pos;
1127 }
1128
1129 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1130 {
1131         (*pos)++;
1132         if (*pos >= ARRAY_SIZE(vmstat_text))
1133                 return NULL;
1134         return (unsigned long *)m->private + *pos;
1135 }
1136
1137 static int vmstat_show(struct seq_file *m, void *arg)
1138 {
1139         unsigned long *l = arg;
1140         unsigned long off = l - (unsigned long *)m->private;
1141
1142         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1143         return 0;
1144 }
1145
1146 static void vmstat_stop(struct seq_file *m, void *arg)
1147 {
1148         kfree(m->private);
1149         m->private = NULL;
1150 }
1151
1152 static const struct seq_operations vmstat_op = {
1153         .start  = vmstat_start,
1154         .next   = vmstat_next,
1155         .stop   = vmstat_stop,
1156         .show   = vmstat_show,
1157 };
1158
1159 static int vmstat_open(struct inode *inode, struct file *file)
1160 {
1161         return seq_open(file, &vmstat_op);
1162 }
1163
1164 static const struct file_operations proc_vmstat_file_operations = {
1165         .open           = vmstat_open,
1166         .read           = seq_read,
1167         .llseek         = seq_lseek,
1168         .release        = seq_release,
1169 };
1170 #endif /* CONFIG_PROC_FS */
1171
1172 #ifdef CONFIG_SMP
1173 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1174 int sysctl_stat_interval __read_mostly = HZ;
1175
1176 static void vmstat_update(struct work_struct *w)
1177 {
1178         refresh_cpu_vm_stats(smp_processor_id());
1179         schedule_delayed_work(&__get_cpu_var(vmstat_work),
1180                 round_jiffies_relative(sysctl_stat_interval));
1181 }
1182
1183 static void __cpuinit start_cpu_timer(int cpu)
1184 {
1185         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1186
1187         INIT_DEFERRABLE_WORK(work, vmstat_update);
1188         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1189 }
1190
1191 /*
1192  * Use the cpu notifier to insure that the thresholds are recalculated
1193  * when necessary.
1194  */
1195 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1196                 unsigned long action,
1197                 void *hcpu)
1198 {
1199         long cpu = (long)hcpu;
1200
1201         switch (action) {
1202         case CPU_ONLINE:
1203         case CPU_ONLINE_FROZEN:
1204                 refresh_zone_stat_thresholds();
1205                 start_cpu_timer(cpu);
1206                 node_set_state(cpu_to_node(cpu), N_CPU);
1207                 break;
1208         case CPU_DOWN_PREPARE:
1209         case CPU_DOWN_PREPARE_FROZEN:
1210                 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1211                 per_cpu(vmstat_work, cpu).work.func = NULL;
1212                 break;
1213         case CPU_DOWN_FAILED:
1214         case CPU_DOWN_FAILED_FROZEN:
1215                 start_cpu_timer(cpu);
1216                 break;
1217         case CPU_DEAD:
1218         case CPU_DEAD_FROZEN:
1219                 refresh_zone_stat_thresholds();
1220                 break;
1221         default:
1222                 break;
1223         }
1224         return NOTIFY_OK;
1225 }
1226
1227 static struct notifier_block __cpuinitdata vmstat_notifier =
1228         { &vmstat_cpuup_callback, NULL, 0 };
1229 #endif
1230
1231 static int __init setup_vmstat(void)
1232 {
1233 #ifdef CONFIG_SMP
1234         int cpu;
1235
1236         register_cpu_notifier(&vmstat_notifier);
1237
1238         for_each_online_cpu(cpu)
1239                 start_cpu_timer(cpu);
1240 #endif
1241 #ifdef CONFIG_PROC_FS
1242         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1243         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1244         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1245         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1246 #endif
1247         return 0;
1248 }
1249 module_init(setup_vmstat)
1250
1251 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1252 #include <linux/debugfs.h>
1253
1254
1255 /*
1256  * Return an index indicating how much of the available free memory is
1257  * unusable for an allocation of the requested size.
1258  */
1259 static int unusable_free_index(unsigned int order,
1260                                 struct contig_page_info *info)
1261 {
1262         /* No free memory is interpreted as all free memory is unusable */
1263         if (info->free_pages == 0)
1264                 return 1000;
1265
1266         /*
1267          * Index should be a value between 0 and 1. Return a value to 3
1268          * decimal places.
1269          *
1270          * 0 => no fragmentation
1271          * 1 => high fragmentation
1272          */
1273         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1274
1275 }
1276
1277 static void unusable_show_print(struct seq_file *m,
1278                                         pg_data_t *pgdat, struct zone *zone)
1279 {
1280         unsigned int order;
1281         int index;
1282         struct contig_page_info info;
1283
1284         seq_printf(m, "Node %d, zone %8s ",
1285                                 pgdat->node_id,
1286                                 zone->name);
1287         for (order = 0; order < MAX_ORDER; ++order) {
1288                 fill_contig_page_info(zone, order, &info);
1289                 index = unusable_free_index(order, &info);
1290                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1291         }
1292
1293         seq_putc(m, '\n');
1294 }
1295
1296 /*
1297  * Display unusable free space index
1298  *
1299  * The unusable free space index measures how much of the available free
1300  * memory cannot be used to satisfy an allocation of a given size and is a
1301  * value between 0 and 1. The higher the value, the more of free memory is
1302  * unusable and by implication, the worse the external fragmentation is. This
1303  * can be expressed as a percentage by multiplying by 100.
1304  */
1305 static int unusable_show(struct seq_file *m, void *arg)
1306 {
1307         pg_data_t *pgdat = (pg_data_t *)arg;
1308
1309         /* check memoryless node */
1310         if (!node_state(pgdat->node_id, N_MEMORY))
1311                 return 0;
1312
1313         walk_zones_in_node(m, pgdat, unusable_show_print);
1314
1315         return 0;
1316 }
1317
1318 static const struct seq_operations unusable_op = {
1319         .start  = frag_start,
1320         .next   = frag_next,
1321         .stop   = frag_stop,
1322         .show   = unusable_show,
1323 };
1324
1325 static int unusable_open(struct inode *inode, struct file *file)
1326 {
1327         return seq_open(file, &unusable_op);
1328 }
1329
1330 static const struct file_operations unusable_file_ops = {
1331         .open           = unusable_open,
1332         .read           = seq_read,
1333         .llseek         = seq_lseek,
1334         .release        = seq_release,
1335 };
1336
1337 static void extfrag_show_print(struct seq_file *m,
1338                                         pg_data_t *pgdat, struct zone *zone)
1339 {
1340         unsigned int order;
1341         int index;
1342
1343         /* Alloc on stack as interrupts are disabled for zone walk */
1344         struct contig_page_info info;
1345
1346         seq_printf(m, "Node %d, zone %8s ",
1347                                 pgdat->node_id,
1348                                 zone->name);
1349         for (order = 0; order < MAX_ORDER; ++order) {
1350                 fill_contig_page_info(zone, order, &info);
1351                 index = __fragmentation_index(order, &info);
1352                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1353         }
1354
1355         seq_putc(m, '\n');
1356 }
1357
1358 /*
1359  * Display fragmentation index for orders that allocations would fail for
1360  */
1361 static int extfrag_show(struct seq_file *m, void *arg)
1362 {
1363         pg_data_t *pgdat = (pg_data_t *)arg;
1364
1365         walk_zones_in_node(m, pgdat, extfrag_show_print);
1366
1367         return 0;
1368 }
1369
1370 static const struct seq_operations extfrag_op = {
1371         .start  = frag_start,
1372         .next   = frag_next,
1373         .stop   = frag_stop,
1374         .show   = extfrag_show,
1375 };
1376
1377 static int extfrag_open(struct inode *inode, struct file *file)
1378 {
1379         return seq_open(file, &extfrag_op);
1380 }
1381
1382 static const struct file_operations extfrag_file_ops = {
1383         .open           = extfrag_open,
1384         .read           = seq_read,
1385         .llseek         = seq_lseek,
1386         .release        = seq_release,
1387 };
1388
1389 static int __init extfrag_debug_init(void)
1390 {
1391         struct dentry *extfrag_debug_root;
1392
1393         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1394         if (!extfrag_debug_root)
1395                 return -ENOMEM;
1396
1397         if (!debugfs_create_file("unusable_index", 0444,
1398                         extfrag_debug_root, NULL, &unusable_file_ops))
1399                 goto fail;
1400
1401         if (!debugfs_create_file("extfrag_index", 0444,
1402                         extfrag_debug_root, NULL, &extfrag_file_ops))
1403                 goto fail;
1404
1405         return 0;
1406 fail:
1407         debugfs_remove_recursive(extfrag_debug_root);
1408         return -ENOMEM;
1409 }
1410
1411 module_init(extfrag_debug_init);
1412 #endif