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 /*
  56  * Fold the foreign cpu events into our own.
  57  *
  58  * This is adding to the events on one processor
  59  * but keeps the global counts constant.
  60  */
  61 void vm_events_fold_cpu(int cpu)
  62 {
  63         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
  64         int i;
  65
  66         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
  67                 count_vm_events(i, fold_state->event[i]);
  68                 fold_state->event[i] = 0;
  69         }
  70 }
  71
  72 #endif /* CONFIG_VM_EVENT_COUNTERS */
  73
  74 /*
  75  * Manage combined zone based / global counters
  76  *
  77  * vm_stat contains the global counters
  78  */
  79 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
  80 EXPORT_SYMBOL(vm_stat);
  81
  82 #ifdef CONFIG_SMP
  83
  84 int calculate_pressure_threshold(struct zone *zone)
  85 {
  86         int threshold;
  87         int watermark_distance;
  88
  89         /*
  90          * As vmstats are not up to date, there is drift between the estimated
  91          * and real values. For high thresholds and a high number of CPUs, it
  92          * is possible for the min watermark to be breached while the estimated
  93          * value looks fine. The pressure threshold is a reduced value such
  94          * that even the maximum amount of drift will not accidentally breach
  95          * the min watermark
  96          */
  97         watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
  98         threshold = max(1, (int)(watermark_distance / num_online_cpus()));
  99
 100         /*
 101          * Maximum threshold is 125
 102          */
 103         threshold = min(125, threshold);
 104
 105         return threshold;
 106 }
 107
 108 int calculate_normal_threshold(struct zone *zone)
 109 {
 110         int threshold;
 111         int mem;        /* memory in 128 MB units */
 112
 113         /*
 114          * The threshold scales with the number of processors and the amount
 115          * of memory per zone. More memory means that we can defer updates for
 116          * longer, more processors could lead to more contention.
 117          * fls() is used to have a cheap way of logarithmic scaling.
 118          *
 119          * Some sample thresholds:
 120          *
 121          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
 122          * ------------------------------------------------------------------
 123          * 8            1               1       0.9-1 GB        4
 124          * 16           2               2       0.9-1 GB        4
 125          * 20           2               2       1-2 GB          5
 126          * 24           2               2       2-4 GB          6
 127          * 28           2               2       4-8 GB          7
 128          * 32           2               2       8-16 GB         8
 129          * 4            2               2       <128M           1
 130          * 30           4               3       2-4 GB          5
 131          * 48           4               3       8-16 GB         8
 132          * 32           8               4       1-2 GB          4
 133          * 32           8               4       0.9-1GB         4
 134          * 10           16              5       <128M           1
 135          * 40           16              5       900M            4
 136          * 70           64              7       2-4 GB          5
 137          * 84           64              7       4-8 GB          6
 138          * 108          512             9       4-8 GB          6
 139          * 125          1024            10      8-16 GB         8
 140          * 125          1024            10      16-32 GB        9
 141          */
 142
 143         mem = zone->managed_pages >> (27 - PAGE_SHIFT);
 144
 145         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
 146
 147         /*
 148          * Maximum threshold is 125
 149          */
 150         threshold = min(125, threshold);
 151
 152         return threshold;
 153 }
 154
 155 /*
 156  * Refresh the thresholds for each zone.
 157  */
 158 void refresh_zone_stat_thresholds(void)
 159 {
 160         struct zone *zone;
 161         int cpu;
 162         int threshold;
 163
 164         for_each_populated_zone(zone) {
 165                 unsigned long max_drift, tolerate_drift;
 166
 167                 threshold = calculate_normal_threshold(zone);
 168
 169                 for_each_online_cpu(cpu)
 170                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 171                                                         = threshold;
 172
 173                 /*
 174                  * Only set percpu_drift_mark if there is a danger that
 175                  * NR_FREE_PAGES reports the low watermark is ok when in fact
 176                  * the min watermark could be breached by an allocation
 177                  */
 178                 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
 179                 max_drift = num_online_cpus() * threshold;
 180                 if (max_drift > tolerate_drift)
 181                         zone->percpu_drift_mark = high_wmark_pages(zone) +
 182                                         max_drift;
 183         }
 184 }
 185
 186 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
 187                                 int (*calculate_pressure)(struct zone *))
 188 {
 189         struct zone *zone;
 190         int cpu;
 191         int threshold;
 192         int i;
 193
 194         for (i = 0; i < pgdat->nr_zones; i++) {
 195                 zone = &pgdat->node_zones[i];
 196                 if (!zone->percpu_drift_mark)
 197                         continue;
 198
 199                 threshold = (*calculate_pressure)(zone);
 200                 for_each_possible_cpu(cpu)
 201                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 202                                                         = threshold;
 203         }
 204 }
 205
 206 /*
 207  * For use when we know that interrupts are disabled.
 208  */
 209 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 210                                 int delta)
 211 {
 212         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 213         s8 __percpu *p = pcp->vm_stat_diff + item;
 214         long x;
 215         long t;
 216
 217         x = delta + __this_cpu_read(*p);
 218
 219         t = __this_cpu_read(pcp->stat_threshold);
 220
 221         if (unlikely(x > t || x < -t)) {
 222                 zone_page_state_add(x, zone, item);
 223                 x = 0;
 224         }
 225         __this_cpu_write(*p, x);
 226 }
 227 EXPORT_SYMBOL(__mod_zone_page_state);
 228
 229 /*
 230  * Optimized increment and decrement functions.
 231  *
 232  * These are only for a single page and therefore can take a struct page *
 233  * argument instead of struct zone *. This allows the inclusion of the code
 234  * generated for page_zone(page) into the optimized functions.
 235  *
 236  * No overflow check is necessary and therefore the differential can be
 237  * incremented or decremented in place which may allow the compilers to
 238  * generate better code.
 239  * The increment or decrement is known and therefore one boundary check can
 240  * be omitted.
 241  *
 242  * NOTE: These functions are very performance sensitive. Change only
 243  * with care.
 244  *
 245  * Some processors have inc/dec instructions that are atomic vs an interrupt.
 246  * However, the code must first determine the differential location in a zone
 247  * based on the processor number and then inc/dec the counter. There is no
 248  * guarantee without disabling preemption that the processor will not change
 249  * in between and therefore the atomicity vs. interrupt cannot be exploited
 250  * in a useful way here.
 251  */
 252 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 253 {
 254         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 255         s8 __percpu *p = pcp->vm_stat_diff + item;
 256         s8 v, t;
 257
 258         v = __this_cpu_inc_return(*p);
 259         t = __this_cpu_read(pcp->stat_threshold);
 260         if (unlikely(v > t)) {
 261                 s8 overstep = t >> 1;
 262
 263                 zone_page_state_add(v + overstep, zone, item);
 264                 __this_cpu_write(*p, -overstep);
 265         }
 266 }
 267
 268 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
 269 {
 270         __inc_zone_state(page_zone(page), item);
 271 }
 272 EXPORT_SYMBOL(__inc_zone_page_state);
 273
 274 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 275 {
 276         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 277         s8 __percpu *p = pcp->vm_stat_diff + item;
 278         s8 v, t;
 279
 280         v = __this_cpu_dec_return(*p);
 281         t = __this_cpu_read(pcp->stat_threshold);
 282         if (unlikely(v < - t)) {
 283                 s8 overstep = t >> 1;
 284
 285                 zone_page_state_add(v - overstep, zone, item);
 286                 __this_cpu_write(*p, overstep);
 287         }
 288 }
 289
 290 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
 291 {
 292         __dec_zone_state(page_zone(page), item);
 293 }
 294 EXPORT_SYMBOL(__dec_zone_page_state);
 295
 296 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
 297 /*
 298  * If we have cmpxchg_local support then we do not need to incur the overhead
 299  * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
 300  *
 301  * mod_state() modifies the zone counter state through atomic per cpu
 302  * operations.
 303  *
 304  * Overstep mode specifies how overstep should handled:
 305  *     0       No overstepping
 306  *     1       Overstepping half of threshold
 307  *     -1      Overstepping minus half of threshold
 308 */
 309 static inline void mod_state(struct zone *zone,
 310        enum zone_stat_item item, int delta, int overstep_mode)
 311 {
 312         struct per_cpu_pageset __percpu *pcp = zone->pageset;
 313         s8 __percpu *p = pcp->vm_stat_diff + item;
 314         long o, n, t, z;
 315
 316         do {
 317                 z = 0;  /* overflow to zone counters */
 318
 319                 /*
 320                  * The fetching of the stat_threshold is racy. We may apply
 321                  * a counter threshold to the wrong the cpu if we get
 322                  * rescheduled while executing here. However, the next
 323                  * counter update will apply the threshold again and
 324                  * therefore bring the counter under the threshold again.
 325                  *
 326                  * Most of the time the thresholds are the same anyways
 327                  * for all cpus in a zone.
 328                  */
 329                 t = this_cpu_read(pcp->stat_threshold);
 330
 331                 o = this_cpu_read(*p);
 332                 n = delta + o;
 333
 334                 if (n > t || n < -t) {
 335                         int os = overstep_mode * (t >> 1) ;
 336
 337                         /* Overflow must be added to zone counters */
 338                         z = n + os;
 339                         n = -os;
 340                 }
 341         } while (this_cpu_cmpxchg(*p, o, n) != o);
 342
 343         if (z)
 344                 zone_page_state_add(z, zone, item);
 345 }
 346
 347 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 348                                         int delta)
 349 {
 350         mod_state(zone, item, delta, 0);
 351 }
 352 EXPORT_SYMBOL(mod_zone_page_state);
 353
 354 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 355 {
 356         mod_state(zone, item, 1, 1);
 357 }
 358
 359 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 360 {
 361         mod_state(page_zone(page), item, 1, 1);
 362 }
 363 EXPORT_SYMBOL(inc_zone_page_state);
 364
 365 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 366 {
 367         mod_state(page_zone(page), item, -1, -1);
 368 }
 369 EXPORT_SYMBOL(dec_zone_page_state);
 370 #else
 371 /*
 372  * Use interrupt disable to serialize counter updates
 373  */
 374 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 375                                         int delta)
 376 {
 377         unsigned long flags;
 378
 379         local_irq_save(flags);
 380         __mod_zone_page_state(zone, item, delta);
 381         local_irq_restore(flags);
 382 }
 383 EXPORT_SYMBOL(mod_zone_page_state);
 384
 385 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 386 {
 387         unsigned long flags;
 388
 389         local_irq_save(flags);
 390         __inc_zone_state(zone, item);
 391         local_irq_restore(flags);
 392 }
 393
 394 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 395 {
 396         unsigned long flags;
 397         struct zone *zone;
 398
 399         zone = page_zone(page);
 400         local_irq_save(flags);
 401         __inc_zone_state(zone, item);
 402         local_irq_restore(flags);
 403 }
 404 EXPORT_SYMBOL(inc_zone_page_state);
 405
 406 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 407 {
 408         unsigned long flags;
 409
 410         local_irq_save(flags);
 411         __dec_zone_page_state(page, item);
 412         local_irq_restore(flags);
 413 }
 414 EXPORT_SYMBOL(dec_zone_page_state);
 415 #endif
 416
 417 static inline void fold_diff(int *diff)
 418 {
 419         int i;
 420
 421         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 422                 if (diff[i])
 423                         atomic_long_add(diff[i], &vm_stat[i]);
 424 }
 425
 426 /*
 427  * Update the zone counters for the current cpu.
 428  *
 429  * Note that refresh_cpu_vm_stats strives to only access
 430  * node local memory. The per cpu pagesets on remote zones are placed
 431  * in the memory local to the processor using that pageset. So the
 432  * loop over all zones will access a series of cachelines local to
 433  * the processor.
 434  *
 435  * The call to zone_page_state_add updates the cachelines with the
 436  * statistics in the remote zone struct as well as the global cachelines
 437  * with the global counters. These could cause remote node cache line
 438  * bouncing and will have to be only done when necessary.
 439  */
 440 static void refresh_cpu_vm_stats(void)
 441 {
 442         struct zone *zone;
 443         int i;
 444         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
 445
 446         for_each_populated_zone(zone) {
 447                 struct per_cpu_pageset __percpu *p = zone->pageset;
 448
 449                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
 450                         int v;
 451
 452                         v = this_cpu_xchg(p->vm_stat_diff[i], 0);
 453                         if (v) {
 454
 455                                 atomic_long_add(v, &zone->vm_stat[i]);
 456                                 global_diff[i] += v;
 457 #ifdef CONFIG_NUMA
 458                                 /* 3 seconds idle till flush */
 459                                 __this_cpu_write(p->expire, 3);
 460 #endif
 461                         }
 462                 }
 463                 cond_resched();
 464 #ifdef CONFIG_NUMA
 465                 /*
 466                  * Deal with draining the remote pageset of this
 467                  * processor
 468                  *
 469                  * Check if there are pages remaining in this pageset
 470                  * if not then there is nothing to expire.
 471                  */
 472                 if (!__this_cpu_read(p->expire) ||
 473                                !__this_cpu_read(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                         __this_cpu_write(p->expire, 0);
 481                         continue;
 482                 }
 483
 484
 485                 if (__this_cpu_dec_return(p->expire))
 486                         continue;
 487
 488                 if (__this_cpu_read(p->pcp.count))
 489                         drain_zone_pages(zone, __this_cpu_ptr(&p->pcp));
 490 #endif
 491         }
 492         fold_diff(global_diff);
 493 }
 494
 495 /*
 496  * Fold the data for an offline cpu into the global array.
 497  * There cannot be any access by the offline cpu and therefore
 498  * synchronization is simplified.
 499  */
 500 void cpu_vm_stats_fold(int cpu)
 501 {
 502         struct zone *zone;
 503         int i;
 504         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
 505
 506         for_each_populated_zone(zone) {
 507                 struct per_cpu_pageset *p;
 508
 509                 p = per_cpu_ptr(zone->pageset, cpu);
 510
 511                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 512                         if (p->vm_stat_diff[i]) {
 513                                 int v;
 514
 515                                 v = p->vm_stat_diff[i];
 516                                 p->vm_stat_diff[i] = 0;
 517                                 atomic_long_add(v, &zone->vm_stat[i]);
 518                                 global_diff[i] += v;
 519                         }
 520         }
 521
 522         fold_diff(global_diff);
 523 }
 524
 525 /*
 526  * this is only called if !populated_zone(zone), which implies no other users of
 527  * pset->vm_stat_diff[] exsist.
 528  */
 529 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
 530 {
 531         int i;
 532
 533         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
 534                 if (pset->vm_stat_diff[i]) {
 535                         int v = pset->vm_stat_diff[i];
 536                         pset->vm_stat_diff[i] = 0;
 537                         atomic_long_add(v, &zone->vm_stat[i]);
 538                         atomic_long_add(v, &vm_stat[i]);
 539                 }
 540 }
 541 #endif
 542
 543 #ifdef CONFIG_NUMA
 544 /*
 545  * zonelist = the list of zones passed to the allocator
 546  * z        = the zone from which the allocation occurred.
 547  *
 548  * Must be called with interrupts disabled.
 549  *
 550  * When __GFP_OTHER_NODE is set assume the node of the preferred
 551  * zone is the local node. This is useful for daemons who allocate
 552  * memory on behalf of other processes.
 553  */
 554 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
 555 {
 556         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
 557                 __inc_zone_state(z, NUMA_HIT);
 558         } else {
 559                 __inc_zone_state(z, NUMA_MISS);
 560                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
 561         }
 562         if (z->node == ((flags & __GFP_OTHER_NODE) ?
 563                         preferred_zone->node : numa_node_id()))
 564                 __inc_zone_state(z, NUMA_LOCAL);
 565         else
 566                 __inc_zone_state(z, NUMA_OTHER);
 567 }
 568 #endif
 569
 570 #ifdef CONFIG_COMPACTION
 571
 572 struct contig_page_info {
 573         unsigned long free_pages;
 574         unsigned long free_blocks_total;
 575         unsigned long free_blocks_suitable;
 576 };
 577
 578 /*
 579  * Calculate the number of free pages in a zone, how many contiguous
 580  * pages are free and how many are large enough to satisfy an allocation of
 581  * the target size. Note that this function makes no attempt to estimate
 582  * how many suitable free blocks there *might* be if MOVABLE pages were
 583  * migrated. Calculating that is possible, but expensive and can be
 584  * figured out from userspace
 585  */
 586 static void fill_contig_page_info(struct zone *zone,
 587                                 unsigned int suitable_order,
 588                                 struct contig_page_info *info)
 589 {
 590         unsigned int order;
 591
 592         info->free_pages = 0;
 593         info->free_blocks_total = 0;
 594         info->free_blocks_suitable = 0;
 595
 596         for (order = 0; order < MAX_ORDER; order++) {
 597                 unsigned long blocks;
 598
 599                 /* Count number of free blocks */
 600                 blocks = zone->free_area[order].nr_free;
 601                 info->free_blocks_total += blocks;
 602
 603                 /* Count free base pages */
 604                 info->free_pages += blocks << order;
 605
 606                 /* Count the suitable free blocks */
 607                 if (order >= suitable_order)
 608                         info->free_blocks_suitable += blocks <<
 609                                                 (order - suitable_order);
 610         }
 611 }
 612
 613 /*
 614  * A fragmentation index only makes sense if an allocation of a requested
 615  * size would fail. If that is true, the fragmentation index indicates
 616  * whether external fragmentation or a lack of memory was the problem.
 617  * The value can be used to determine if page reclaim or compaction
 618  * should be used
 619  */
 620 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
 621 {
 622         unsigned long requested = 1UL << order;
 623
 624         if (!info->free_blocks_total)
 625                 return 0;
 626
 627         /* Fragmentation index only makes sense when a request would fail */
 628         if (info->free_blocks_suitable)
 629                 return -1000;
 630
 631         /*
 632          * Index is between 0 and 1 so return within 3 decimal places
 633          *
 634          * 0 => allocation would fail due to lack of memory
 635          * 1 => allocation would fail due to fragmentation
 636          */
 637         return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
 638 }
 639
 640 /* Same as __fragmentation index but allocs contig_page_info on stack */
 641 int fragmentation_index(struct zone *zone, unsigned int order)
 642 {
 643         struct contig_page_info info;
 644
 645         fill_contig_page_info(zone, order, &info);
 646         return __fragmentation_index(order, &info);
 647 }
 648 #endif
 649
 650 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
 651 #include <linux/proc_fs.h>
 652 #include <linux/seq_file.h>
 653
 654 static char * const migratetype_names[MIGRATE_TYPES] = {
 655         "Unmovable",
 656         "Reclaimable",
 657         "Movable",
 658         "Reserve",
 659 #ifdef CONFIG_CMA
 660         "CMA",
 661 #endif
 662 #ifdef CONFIG_MEMORY_ISOLATION
 663         "Isolate",
 664 #endif
 665 };
 666
 667 static void *frag_start(struct seq_file *m, loff_t *pos)
 668 {
 669         pg_data_t *pgdat;
 670         loff_t node = *pos;
 671         for (pgdat = first_online_pgdat();
 672              pgdat && node;
 673              pgdat = next_online_pgdat(pgdat))
 674                 --node;
 675
 676         return pgdat;
 677 }
 678
 679 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
 680 {
 681         pg_data_t *pgdat = (pg_data_t *)arg;
 682
 683         (*pos)++;
 684         return next_online_pgdat(pgdat);
 685 }
 686
 687 static void frag_stop(struct seq_file *m, void *arg)
 688 {
 689 }
 690
 691 /* Walk all the zones in a node and print using a callback */
 692 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 693                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 694 {
 695         struct zone *zone;
 696         struct zone *node_zones = pgdat->node_zones;
 697         unsigned long flags;
 698
 699         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
 700                 if (!populated_zone(zone))
 701                         continue;
 702
 703                 spin_lock_irqsave(&zone->lock, flags);
 704                 print(m, pgdat, zone);
 705                 spin_unlock_irqrestore(&zone->lock, flags);
 706         }
 707 }
 708 #endif
 709
 710 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
 711 #ifdef CONFIG_ZONE_DMA
 712 #define TEXT_FOR_DMA(xx) xx "_dma",
 713 #else
 714 #define TEXT_FOR_DMA(xx)
 715 #endif
 716
 717 #ifdef CONFIG_ZONE_DMA32
 718 #define TEXT_FOR_DMA32(xx) xx "_dma32",
 719 #else
 720 #define TEXT_FOR_DMA32(xx)
 721 #endif
 722
 723 #ifdef CONFIG_HIGHMEM
 724 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
 725 #else
 726 #define TEXT_FOR_HIGHMEM(xx)
 727 #endif
 728
 729 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
 730                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
 731
 732 const char * const vmstat_text[] = {
 733         /* Zoned VM counters */
 734         "nr_free_pages",
 735         "nr_alloc_batch",
 736         "nr_inactive_anon",
 737         "nr_active_anon",
 738         "nr_inactive_file",
 739         "nr_active_file",
 740         "nr_unevictable",
 741         "nr_mlock",
 742         "nr_anon_pages",
 743         "nr_mapped",
 744         "nr_file_pages",
 745         "nr_dirty",
 746         "nr_writeback",
 747         "nr_slab_reclaimable",
 748         "nr_slab_unreclaimable",
 749         "nr_page_table_pages",
 750         "nr_kernel_stack",
 751         "nr_unstable",
 752         "nr_bounce",
 753         "nr_vmscan_write",
 754         "nr_vmscan_immediate_reclaim",
 755         "nr_writeback_temp",
 756         "nr_isolated_anon",
 757         "nr_isolated_file",
 758         "nr_shmem",
 759         "nr_dirtied",
 760         "nr_written",
 761
 762 #ifdef CONFIG_NUMA
 763         "numa_hit",
 764         "numa_miss",
 765         "numa_foreign",
 766         "numa_interleave",
 767         "numa_local",
 768         "numa_other",
 769 #endif
 770         "nr_anon_transparent_hugepages",
 771         "nr_free_cma",
 772         "nr_dirty_threshold",
 773         "nr_dirty_background_threshold",
 774
 775 #ifdef CONFIG_VM_EVENT_COUNTERS
 776         "pgpgin",
 777         "pgpgout",
 778         "pswpin",
 779         "pswpout",
 780
 781         TEXTS_FOR_ZONES("pgalloc")
 782
 783         "pgfree",
 784         "pgactivate",
 785         "pgdeactivate",
 786
 787         "pgfault",
 788         "pgmajfault",
 789
 790         TEXTS_FOR_ZONES("pgrefill")
 791         TEXTS_FOR_ZONES("pgsteal_kswapd")
 792         TEXTS_FOR_ZONES("pgsteal_direct")
 793         TEXTS_FOR_ZONES("pgscan_kswapd")
 794         TEXTS_FOR_ZONES("pgscan_direct")
 795         "pgscan_direct_throttle",
 796
 797 #ifdef CONFIG_NUMA
 798         "zone_reclaim_failed",
 799 #endif
 800         "pginodesteal",
 801         "slabs_scanned",
 802         "kswapd_inodesteal",
 803         "kswapd_low_wmark_hit_quickly",
 804         "kswapd_high_wmark_hit_quickly",
 805         "pageoutrun",
 806         "allocstall",
 807
 808         "pgrotated",
 809
 810 #ifdef CONFIG_NUMA_BALANCING
 811         "numa_pte_updates",
 812         "numa_hint_faults",
 813         "numa_hint_faults_local",
 814         "numa_pages_migrated",
 815 #endif
 816 #ifdef CONFIG_MIGRATION
 817         "pgmigrate_success",
 818         "pgmigrate_fail",
 819 #endif
 820 #ifdef CONFIG_COMPACTION
 821         "compact_migrate_scanned",
 822         "compact_free_scanned",
 823         "compact_isolated",
 824         "compact_stall",
 825         "compact_fail",
 826         "compact_success",
 827 #endif
 828
 829 #ifdef CONFIG_HUGETLB_PAGE
 830         "htlb_buddy_alloc_success",
 831         "htlb_buddy_alloc_fail",
 832 #endif
 833         "unevictable_pgs_culled",
 834         "unevictable_pgs_scanned",
 835         "unevictable_pgs_rescued",
 836         "unevictable_pgs_mlocked",
 837         "unevictable_pgs_munlocked",
 838         "unevictable_pgs_cleared",
 839         "unevictable_pgs_stranded",
 840
 841 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 842         "thp_fault_alloc",
 843         "thp_fault_fallback",
 844         "thp_collapse_alloc",
 845         "thp_collapse_alloc_failed",
 846         "thp_split",
 847         "thp_zero_page_alloc",
 848         "thp_zero_page_alloc_failed",
 849 #endif
 850 #ifdef CONFIG_SMP
 851         "nr_tlb_remote_flush",
 852         "nr_tlb_remote_flush_received",
 853 #endif
 854         "nr_tlb_local_flush_all",
 855         "nr_tlb_local_flush_one",
 856
 857 #endif /* CONFIG_VM_EVENTS_COUNTERS */
 858 };
 859 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
 860
 861
 862 #ifdef CONFIG_PROC_FS
 863 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
 864                                                 struct zone *zone)
 865 {
 866         int order;
 867
 868         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 869         for (order = 0; order < MAX_ORDER; ++order)
 870                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
 871         seq_putc(m, '\n');
 872 }
 873
 874 /*
 875  * This walks the free areas for each zone.
 876  */
 877 static int frag_show(struct seq_file *m, void *arg)
 878 {
 879         pg_data_t *pgdat = (pg_data_t *)arg;
 880         walk_zones_in_node(m, pgdat, frag_show_print);
 881         return 0;
 882 }
 883
 884 static void pagetypeinfo_showfree_print(struct seq_file *m,
 885                                         pg_data_t *pgdat, struct zone *zone)
 886 {
 887         int order, mtype;
 888
 889         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
 890                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
 891                                         pgdat->node_id,
 892                                         zone->name,
 893                                         migratetype_names[mtype]);
 894                 for (order = 0; order < MAX_ORDER; ++order) {
 895                         unsigned long freecount = 0;
 896                         struct free_area *area;
 897                         struct list_head *curr;
 898
 899                         area = &(zone->free_area[order]);
 900
 901                         list_for_each(curr, &area->free_list[mtype])
 902                                 freecount++;
 903                         seq_printf(m, "%6lu ", freecount);
 904                 }
 905                 seq_putc(m, '\n');
 906         }
 907 }
 908
 909 /* Print out the free pages at each order for each migatetype */
 910 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
 911 {
 912         int order;
 913         pg_data_t *pgdat = (pg_data_t *)arg;
 914
 915         /* Print header */
 916         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
 917         for (order = 0; order < MAX_ORDER; ++order)
 918                 seq_printf(m, "%6d ", order);
 919         seq_putc(m, '\n');
 920
 921         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
 922
 923         return 0;
 924 }
 925
 926 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 927                                         pg_data_t *pgdat, struct zone *zone)
 928 {
 929         int mtype;
 930         unsigned long pfn;
 931         unsigned long start_pfn = zone->zone_start_pfn;
 932         unsigned long end_pfn = zone_end_pfn(zone);
 933         unsigned long count[MIGRATE_TYPES] = { 0, };
 934
 935         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
 936                 struct page *page;
 937
 938                 if (!pfn_valid(pfn))
 939                         continue;
 940
 941                 page = pfn_to_page(pfn);
 942
 943                 /* Watch for unexpected holes punched in the memmap */
 944                 if (!memmap_valid_within(pfn, page, zone))
 945                         continue;
 946
 947                 mtype = get_pageblock_migratetype(page);
 948
 949                 if (mtype < MIGRATE_TYPES)
 950                         count[mtype]++;
 951         }
 952
 953         /* Print counts */
 954         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
 955         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 956                 seq_printf(m, "%12lu ", count[mtype]);
 957         seq_putc(m, '\n');
 958 }
 959
 960 /* Print out the free pages at each order for each migratetype */
 961 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
 962 {
 963         int mtype;
 964         pg_data_t *pgdat = (pg_data_t *)arg;
 965
 966         seq_printf(m, "\n%-23s", "Number of blocks type ");
 967         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 968                 seq_printf(m, "%12s ", migratetype_names[mtype]);
 969         seq_putc(m, '\n');
 970         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
 971
 972         return 0;
 973 }
 974
 975 /*
 976  * This prints out statistics in relation to grouping pages by mobility.
 977  * It is expensive to collect so do not constantly read the file.
 978  */
 979 static int pagetypeinfo_show(struct seq_file *m, void *arg)
 980 {
 981         pg_data_t *pgdat = (pg_data_t *)arg;
 982
 983         /* check memoryless node */
 984         if (!node_state(pgdat->node_id, N_MEMORY))
 985                 return 0;
 986
 987         seq_printf(m, "Page block order: %d\n", pageblock_order);
 988         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
 989         seq_putc(m, '\n');
 990         pagetypeinfo_showfree(m, pgdat);
 991         pagetypeinfo_showblockcount(m, pgdat);
 992
 993         return 0;
 994 }
 995
 996 static const struct seq_operations fragmentation_op = {
 997         .start  = frag_start,
 998         .next   = frag_next,
 999         .stop   = frag_stop,
1000         .show   = frag_show,
1001 };
1002
1003 static int fragmentation_open(struct inode *inode, struct file *file)
1004 {
1005         return seq_open(file, &fragmentation_op);
1006 }
1007
1008 static const struct file_operations fragmentation_file_operations = {
1009         .open           = fragmentation_open,
1010         .read           = seq_read,
1011         .llseek         = seq_lseek,
1012         .release        = seq_release,
1013 };
1014
1015 static const struct seq_operations pagetypeinfo_op = {
1016         .start  = frag_start,
1017         .next   = frag_next,
1018         .stop   = frag_stop,
1019         .show   = pagetypeinfo_show,
1020 };
1021
1022 static int pagetypeinfo_open(struct inode *inode, struct file *file)
1023 {
1024         return seq_open(file, &pagetypeinfo_op);
1025 }
1026
1027 static const struct file_operations pagetypeinfo_file_ops = {
1028         .open           = pagetypeinfo_open,
1029         .read           = seq_read,
1030         .llseek         = seq_lseek,
1031         .release        = seq_release,
1032 };
1033
1034 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1035                                                         struct zone *zone)
1036 {
1037         int i;
1038         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1039         seq_printf(m,
1040                    "\n  pages free     %lu"
1041                    "\n        min      %lu"
1042                    "\n        low      %lu"
1043                    "\n        high     %lu"
1044                    "\n        scanned  %lu"
1045                    "\n        spanned  %lu"
1046                    "\n        present  %lu"
1047                    "\n        managed  %lu",
1048                    zone_page_state(zone, NR_FREE_PAGES),
1049                    min_wmark_pages(zone),
1050                    low_wmark_pages(zone),
1051                    high_wmark_pages(zone),
1052                    zone->pages_scanned,
1053                    zone->spanned_pages,
1054                    zone->present_pages,
1055                    zone->managed_pages);
1056
1057         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1058                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
1059                                 zone_page_state(zone, i));
1060
1061         seq_printf(m,
1062                    "\n        protection: (%lu",
1063                    zone->lowmem_reserve[0]);
1064         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1065                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
1066         seq_printf(m,
1067                    ")"
1068                    "\n  pagesets");
1069         for_each_online_cpu(i) {
1070                 struct per_cpu_pageset *pageset;
1071
1072                 pageset = per_cpu_ptr(zone->pageset, i);
1073                 seq_printf(m,
1074                            "\n    cpu: %i"
1075                            "\n              count: %i"
1076                            "\n              high:  %i"
1077                            "\n              batch: %i",
1078                            i,
1079                            pageset->pcp.count,
1080                            pageset->pcp.high,
1081                            pageset->pcp.batch);
1082 #ifdef CONFIG_SMP
1083                 seq_printf(m, "\n  vm stats threshold: %d",
1084                                 pageset->stat_threshold);
1085 #endif
1086         }
1087         seq_printf(m,
1088                    "\n  all_unreclaimable: %u"
1089                    "\n  start_pfn:         %lu"
1090                    "\n  inactive_ratio:    %u",
1091                    zone->all_unreclaimable,
1092                    zone->zone_start_pfn,
1093                    zone->inactive_ratio);
1094         seq_putc(m, '\n');
1095 }
1096
1097 /*
1098  * Output information about zones in @pgdat.
1099  */
1100 static int zoneinfo_show(struct seq_file *m, void *arg)
1101 {
1102         pg_data_t *pgdat = (pg_data_t *)arg;
1103         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1104         return 0;
1105 }
1106
1107 static const struct seq_operations zoneinfo_op = {
1108         .start  = frag_start, /* iterate over all zones. The same as in
1109                                * fragmentation. */
1110         .next   = frag_next,
1111         .stop   = frag_stop,
1112         .show   = zoneinfo_show,
1113 };
1114
1115 static int zoneinfo_open(struct inode *inode, struct file *file)
1116 {
1117         return seq_open(file, &zoneinfo_op);
1118 }
1119
1120 static const struct file_operations proc_zoneinfo_file_operations = {
1121         .open           = zoneinfo_open,
1122         .read           = seq_read,
1123         .llseek         = seq_lseek,
1124         .release        = seq_release,
1125 };
1126
1127 enum writeback_stat_item {
1128         NR_DIRTY_THRESHOLD,
1129         NR_DIRTY_BG_THRESHOLD,
1130         NR_VM_WRITEBACK_STAT_ITEMS,
1131 };
1132
1133 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1134 {
1135         unsigned long *v;
1136         int i, stat_items_size;
1137
1138         if (*pos >= ARRAY_SIZE(vmstat_text))
1139                 return NULL;
1140         stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1141                           NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1142
1143 #ifdef CONFIG_VM_EVENT_COUNTERS
1144         stat_items_size += sizeof(struct vm_event_state);
1145 #endif
1146
1147         v = kmalloc(stat_items_size, GFP_KERNEL);
1148         m->private = v;
1149         if (!v)
1150                 return ERR_PTR(-ENOMEM);
1151         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1152                 v[i] = global_page_state(i);
1153         v += NR_VM_ZONE_STAT_ITEMS;
1154
1155         global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1156                             v + NR_DIRTY_THRESHOLD);
1157         v += NR_VM_WRITEBACK_STAT_ITEMS;
1158
1159 #ifdef CONFIG_VM_EVENT_COUNTERS
1160         all_vm_events(v);
1161         v[PGPGIN] /= 2;         /* sectors -> kbytes */
1162         v[PGPGOUT] /= 2;
1163 #endif
1164         return (unsigned long *)m->private + *pos;
1165 }
1166
1167 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1168 {
1169         (*pos)++;
1170         if (*pos >= ARRAY_SIZE(vmstat_text))
1171                 return NULL;
1172         return (unsigned long *)m->private + *pos;
1173 }
1174
1175 static int vmstat_show(struct seq_file *m, void *arg)
1176 {
1177         unsigned long *l = arg;
1178         unsigned long off = l - (unsigned long *)m->private;
1179
1180         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1181         return 0;
1182 }
1183
1184 static void vmstat_stop(struct seq_file *m, void *arg)
1185 {
1186         kfree(m->private);
1187         m->private = NULL;
1188 }
1189
1190 static const struct seq_operations vmstat_op = {
1191         .start  = vmstat_start,
1192         .next   = vmstat_next,
1193         .stop   = vmstat_stop,
1194         .show   = vmstat_show,
1195 };
1196
1197 static int vmstat_open(struct inode *inode, struct file *file)
1198 {
1199         return seq_open(file, &vmstat_op);
1200 }
1201
1202 static const struct file_operations proc_vmstat_file_operations = {
1203         .open           = vmstat_open,
1204         .read           = seq_read,
1205         .llseek         = seq_lseek,
1206         .release        = seq_release,
1207 };
1208 #endif /* CONFIG_PROC_FS */
1209
1210 #ifdef CONFIG_SMP
1211 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1212 int sysctl_stat_interval __read_mostly = HZ;
1213
1214 static void vmstat_update(struct work_struct *w)
1215 {
1216         refresh_cpu_vm_stats();
1217         schedule_delayed_work(&__get_cpu_var(vmstat_work),
1218                 round_jiffies_relative(sysctl_stat_interval));
1219 }
1220
1221 static void start_cpu_timer(int cpu)
1222 {
1223         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1224
1225         INIT_DEFERRABLE_WORK(work, vmstat_update);
1226         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1227 }
1228
1229 /*
1230  * Use the cpu notifier to insure that the thresholds are recalculated
1231  * when necessary.
1232  */
1233 static int vmstat_cpuup_callback(struct notifier_block *nfb,
1234                 unsigned long action,
1235                 void *hcpu)
1236 {
1237         long cpu = (long)hcpu;
1238
1239         switch (action) {
1240         case CPU_ONLINE:
1241         case CPU_ONLINE_FROZEN:
1242                 refresh_zone_stat_thresholds();
1243                 start_cpu_timer(cpu);
1244                 node_set_state(cpu_to_node(cpu), N_CPU);
1245                 break;
1246         case CPU_DOWN_PREPARE:
1247         case CPU_DOWN_PREPARE_FROZEN:
1248                 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1249                 per_cpu(vmstat_work, cpu).work.func = NULL;
1250                 break;
1251         case CPU_DOWN_FAILED:
1252         case CPU_DOWN_FAILED_FROZEN:
1253                 start_cpu_timer(cpu);
1254                 break;
1255         case CPU_DEAD:
1256         case CPU_DEAD_FROZEN:
1257                 refresh_zone_stat_thresholds();
1258                 break;
1259         default:
1260                 break;
1261         }
1262         return NOTIFY_OK;
1263 }
1264
1265 static struct notifier_block vmstat_notifier =
1266         { &vmstat_cpuup_callback, NULL, 0 };
1267 #endif
1268
1269 static int __init setup_vmstat(void)
1270 {
1271 #ifdef CONFIG_SMP
1272         int cpu;
1273
1274         register_cpu_notifier(&vmstat_notifier);
1275
1276         for_each_online_cpu(cpu)
1277                 start_cpu_timer(cpu);
1278 #endif
1279 #ifdef CONFIG_PROC_FS
1280         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1281         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1282         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1283         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1284 #endif
1285         return 0;
1286 }
1287 module_init(setup_vmstat)
1288
1289 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1290 #include <linux/debugfs.h>
1291
1292
1293 /*
1294  * Return an index indicating how much of the available free memory is
1295  * unusable for an allocation of the requested size.
1296  */
1297 static int unusable_free_index(unsigned int order,
1298                                 struct contig_page_info *info)
1299 {
1300         /* No free memory is interpreted as all free memory is unusable */
1301         if (info->free_pages == 0)
1302                 return 1000;
1303
1304         /*
1305          * Index should be a value between 0 and 1. Return a value to 3
1306          * decimal places.
1307          *
1308          * 0 => no fragmentation
1309          * 1 => high fragmentation
1310          */
1311         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1312
1313 }
1314
1315 static void unusable_show_print(struct seq_file *m,
1316                                         pg_data_t *pgdat, struct zone *zone)
1317 {
1318         unsigned int order;
1319         int index;
1320         struct contig_page_info info;
1321
1322         seq_printf(m, "Node %d, zone %8s ",
1323                                 pgdat->node_id,
1324                                 zone->name);
1325         for (order = 0; order < MAX_ORDER; ++order) {
1326                 fill_contig_page_info(zone, order, &info);
1327                 index = unusable_free_index(order, &info);
1328                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1329         }
1330
1331         seq_putc(m, '\n');
1332 }
1333
1334 /*
1335  * Display unusable free space index
1336  *
1337  * The unusable free space index measures how much of the available free
1338  * memory cannot be used to satisfy an allocation of a given size and is a
1339  * value between 0 and 1. The higher the value, the more of free memory is
1340  * unusable and by implication, the worse the external fragmentation is. This
1341  * can be expressed as a percentage by multiplying by 100.
1342  */
1343 static int unusable_show(struct seq_file *m, void *arg)
1344 {
1345         pg_data_t *pgdat = (pg_data_t *)arg;
1346
1347         /* check memoryless node */
1348         if (!node_state(pgdat->node_id, N_MEMORY))
1349                 return 0;
1350
1351         walk_zones_in_node(m, pgdat, unusable_show_print);
1352
1353         return 0;
1354 }
1355
1356 static const struct seq_operations unusable_op = {
1357         .start  = frag_start,
1358         .next   = frag_next,
1359         .stop   = frag_stop,
1360         .show   = unusable_show,
1361 };
1362
1363 static int unusable_open(struct inode *inode, struct file *file)
1364 {
1365         return seq_open(file, &unusable_op);
1366 }
1367
1368 static const struct file_operations unusable_file_ops = {
1369         .open           = unusable_open,
1370         .read           = seq_read,
1371         .llseek         = seq_lseek,
1372         .release        = seq_release,
1373 };
1374
1375 static void extfrag_show_print(struct seq_file *m,
1376                                         pg_data_t *pgdat, struct zone *zone)
1377 {
1378         unsigned int order;
1379         int index;
1380
1381         /* Alloc on stack as interrupts are disabled for zone walk */
1382         struct contig_page_info info;
1383
1384         seq_printf(m, "Node %d, zone %8s ",
1385                                 pgdat->node_id,
1386                                 zone->name);
1387         for (order = 0; order < MAX_ORDER; ++order) {
1388                 fill_contig_page_info(zone, order, &info);
1389                 index = __fragmentation_index(order, &info);
1390                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1391         }
1392
1393         seq_putc(m, '\n');
1394 }
1395
1396 /*
1397  * Display fragmentation index for orders that allocations would fail for
1398  */
1399 static int extfrag_show(struct seq_file *m, void *arg)
1400 {
1401         pg_data_t *pgdat = (pg_data_t *)arg;
1402
1403         walk_zones_in_node(m, pgdat, extfrag_show_print);
1404
1405         return 0;
1406 }
1407
1408 static const struct seq_operations extfrag_op = {
1409         .start  = frag_start,
1410         .next   = frag_next,
1411         .stop   = frag_stop,
1412         .show   = extfrag_show,
1413 };
1414
1415 static int extfrag_open(struct inode *inode, struct file *file)
1416 {
1417         return seq_open(file, &extfrag_op);
1418 }
1419
1420 static const struct file_operations extfrag_file_ops = {
1421         .open           = extfrag_open,
1422         .read           = seq_read,
1423         .llseek         = seq_lseek,
1424         .release        = seq_release,
1425 };
1426
1427 static int __init extfrag_debug_init(void)
1428 {
1429         struct dentry *extfrag_debug_root;
1430
1431         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1432         if (!extfrag_debug_root)
1433                 return -ENOMEM;
1434
1435         if (!debugfs_create_file("unusable_index", 0444,
1436                         extfrag_debug_root, NULL, &unusable_file_ops))
1437                 goto fail;
1438
1439         if (!debugfs_create_file("extfrag_index", 0444,
1440                         extfrag_debug_root, NULL, &extfrag_file_ops))
1441                 goto fail;
1442
1443         return 0;
1444 fail:
1445         debugfs_remove_recursive(extfrag_debug_root);
1446         return -ENOMEM;
1447 }
1448
1449 module_init(extfrag_debug_init);
1450 #endif