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Linux/mm/vmstat.c

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  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 #include <linux/mm_inline.h>
 23 
 24 #include "internal.h"
 25 
 26 #ifdef CONFIG_VM_EVENT_COUNTERS
 27 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
 28 EXPORT_PER_CPU_SYMBOL(vm_event_states);
 29 
 30 static void sum_vm_events(unsigned long *ret)
 31 {
 32         int cpu;
 33         int i;
 34 
 35         memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
 36 
 37         for_each_online_cpu(cpu) {
 38                 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
 39 
 40                 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
 41                         ret[i] += this->event[i];
 42         }
 43 }
 44 
 45 /*
 46  * Accumulate the vm event counters across all CPUs.
 47  * The result is unavoidably approximate - it can change
 48  * during and after execution of this function.
 49 */
 50 void all_vm_events(unsigned long *ret)
 51 {
 52         get_online_cpus();
 53         sum_vm_events(ret);
 54         put_online_cpus();
 55 }
 56 EXPORT_SYMBOL_GPL(all_vm_events);
 57 
 58 /*
 59  * Fold the foreign cpu events into our own.
 60  *
 61  * This is adding to the events on one processor
 62  * but keeps the global counts constant.
 63  */
 64 void vm_events_fold_cpu(int cpu)
 65 {
 66         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
 67         int i;
 68 
 69         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
 70                 count_vm_events(i, fold_state->event[i]);
 71                 fold_state->event[i] = 0;
 72         }
 73 }
 74 
 75 #endif /* CONFIG_VM_EVENT_COUNTERS */
 76 
 77 /*
 78  * Manage combined zone based / global counters
 79  *
 80  * vm_stat contains the global counters
 81  */
 82 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
 83 EXPORT_SYMBOL(vm_stat);
 84 
 85 #ifdef CONFIG_SMP
 86 
 87 int calculate_pressure_threshold(struct zone *zone)
 88 {
 89         int threshold;
 90         int watermark_distance;
 91 
 92         /*
 93          * As vmstats are not up to date, there is drift between the estimated
 94          * and real values. For high thresholds and a high number of CPUs, it
 95          * is possible for the min watermark to be breached while the estimated
 96          * value looks fine. The pressure threshold is a reduced value such
 97          * that even the maximum amount of drift will not accidentally breach
 98          * the min watermark
 99          */
100         watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
101         threshold = max(1, (int)(watermark_distance / num_online_cpus()));
102 
103         /*
104          * Maximum threshold is 125
105          */
106         threshold = min(125, threshold);
107 
108         return threshold;
109 }
110 
111 int calculate_normal_threshold(struct zone *zone)
112 {
113         int threshold;
114         int mem;        /* memory in 128 MB units */
115 
116         /*
117          * The threshold scales with the number of processors and the amount
118          * of memory per zone. More memory means that we can defer updates for
119          * longer, more processors could lead to more contention.
120          * fls() is used to have a cheap way of logarithmic scaling.
121          *
122          * Some sample thresholds:
123          *
124          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
125          * ------------------------------------------------------------------
126          * 8            1               1       0.9-1 GB        4
127          * 16           2               2       0.9-1 GB        4
128          * 20           2               2       1-2 GB          5
129          * 24           2               2       2-4 GB          6
130          * 28           2               2       4-8 GB          7
131          * 32           2               2       8-16 GB         8
132          * 4            2               2       <128M           1
133          * 30           4               3       2-4 GB          5
134          * 48           4               3       8-16 GB         8
135          * 32           8               4       1-2 GB          4
136          * 32           8               4       0.9-1GB         4
137          * 10           16              5       <128M           1
138          * 40           16              5       900M            4
139          * 70           64              7       2-4 GB          5
140          * 84           64              7       4-8 GB          6
141          * 108          512             9       4-8 GB          6
142          * 125          1024            10      8-16 GB         8
143          * 125          1024            10      16-32 GB        9
144          */
145 
146         mem = zone->managed_pages >> (27 - PAGE_SHIFT);
147 
148         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
149 
150         /*
151          * Maximum threshold is 125
152          */
153         threshold = min(125, threshold);
154 
155         return threshold;
156 }
157 
158 /*
159  * Refresh the thresholds for each zone.
160  */
161 void refresh_zone_stat_thresholds(void)
162 {
163         struct zone *zone;
164         int cpu;
165         int threshold;
166 
167         for_each_populated_zone(zone) {
168                 unsigned long max_drift, tolerate_drift;
169 
170                 threshold = calculate_normal_threshold(zone);
171 
172                 for_each_online_cpu(cpu)
173                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
174                                                         = threshold;
175 
176                 /*
177                  * Only set percpu_drift_mark if there is a danger that
178                  * NR_FREE_PAGES reports the low watermark is ok when in fact
179                  * the min watermark could be breached by an allocation
180                  */
181                 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
182                 max_drift = num_online_cpus() * threshold;
183                 if (max_drift > tolerate_drift)
184                         zone->percpu_drift_mark = high_wmark_pages(zone) +
185                                         max_drift;
186         }
187 }
188 
189 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
190                                 int (*calculate_pressure)(struct zone *))
191 {
192         struct zone *zone;
193         int cpu;
194         int threshold;
195         int i;
196 
197         for (i = 0; i < pgdat->nr_zones; i++) {
198                 zone = &pgdat->node_zones[i];
199                 if (!zone->percpu_drift_mark)
200                         continue;
201 
202                 threshold = (*calculate_pressure)(zone);
203                 for_each_online_cpu(cpu)
204                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
205                                                         = threshold;
206         }
207 }
208 
209 /*
210  * For use when we know that interrupts are disabled.
211  */
212 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
213                                 int delta)
214 {
215         struct per_cpu_pageset __percpu *pcp = zone->pageset;
216         s8 __percpu *p = pcp->vm_stat_diff + item;
217         long x;
218         long t;
219 
220         x = delta + __this_cpu_read(*p);
221 
222         t = __this_cpu_read(pcp->stat_threshold);
223 
224         if (unlikely(x > t || x < -t)) {
225                 zone_page_state_add(x, zone, item);
226                 x = 0;
227         }
228         __this_cpu_write(*p, x);
229 }
230 EXPORT_SYMBOL(__mod_zone_page_state);
231 
232 /*
233  * Optimized increment and decrement functions.
234  *
235  * These are only for a single page and therefore can take a struct page *
236  * argument instead of struct zone *. This allows the inclusion of the code
237  * generated for page_zone(page) into the optimized functions.
238  *
239  * No overflow check is necessary and therefore the differential can be
240  * incremented or decremented in place which may allow the compilers to
241  * generate better code.
242  * The increment or decrement is known and therefore one boundary check can
243  * be omitted.
244  *
245  * NOTE: These functions are very performance sensitive. Change only
246  * with care.
247  *
248  * Some processors have inc/dec instructions that are atomic vs an interrupt.
249  * However, the code must first determine the differential location in a zone
250  * based on the processor number and then inc/dec the counter. There is no
251  * guarantee without disabling preemption that the processor will not change
252  * in between and therefore the atomicity vs. interrupt cannot be exploited
253  * in a useful way here.
254  */
255 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
256 {
257         struct per_cpu_pageset __percpu *pcp = zone->pageset;
258         s8 __percpu *p = pcp->vm_stat_diff + item;
259         s8 v, t;
260 
261         v = __this_cpu_inc_return(*p);
262         t = __this_cpu_read(pcp->stat_threshold);
263         if (unlikely(v > t)) {
264                 s8 overstep = t >> 1;
265 
266                 zone_page_state_add(v + overstep, zone, item);
267                 __this_cpu_write(*p, -overstep);
268         }
269 }
270 
271 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
272 {
273         __inc_zone_state(page_zone(page), item);
274 }
275 EXPORT_SYMBOL(__inc_zone_page_state);
276 
277 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
278 {
279         struct per_cpu_pageset __percpu *pcp = zone->pageset;
280         s8 __percpu *p = pcp->vm_stat_diff + item;
281         s8 v, t;
282 
283         v = __this_cpu_dec_return(*p);
284         t = __this_cpu_read(pcp->stat_threshold);
285         if (unlikely(v < - t)) {
286                 s8 overstep = t >> 1;
287 
288                 zone_page_state_add(v - overstep, zone, item);
289                 __this_cpu_write(*p, overstep);
290         }
291 }
292 
293 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
294 {
295         __dec_zone_state(page_zone(page), item);
296 }
297 EXPORT_SYMBOL(__dec_zone_page_state);
298 
299 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
300 /*
301  * If we have cmpxchg_local support then we do not need to incur the overhead
302  * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
303  *
304  * mod_state() modifies the zone counter state through atomic per cpu
305  * operations.
306  *
307  * Overstep mode specifies how overstep should handled:
308  *     0       No overstepping
309  *     1       Overstepping half of threshold
310  *     -1      Overstepping minus half of threshold
311 */
312 static inline void mod_state(struct zone *zone,
313        enum zone_stat_item item, int delta, int overstep_mode)
314 {
315         struct per_cpu_pageset __percpu *pcp = zone->pageset;
316         s8 __percpu *p = pcp->vm_stat_diff + item;
317         long o, n, t, z;
318 
319         do {
320                 z = 0;  /* overflow to zone counters */
321 
322                 /*
323                  * The fetching of the stat_threshold is racy. We may apply
324                  * a counter threshold to the wrong the cpu if we get
325                  * rescheduled while executing here. However, the next
326                  * counter update will apply the threshold again and
327                  * therefore bring the counter under the threshold again.
328                  *
329                  * Most of the time the thresholds are the same anyways
330                  * for all cpus in a zone.
331                  */
332                 t = this_cpu_read(pcp->stat_threshold);
333 
334                 o = this_cpu_read(*p);
335                 n = delta + o;
336 
337                 if (n > t || n < -t) {
338                         int os = overstep_mode * (t >> 1) ;
339 
340                         /* Overflow must be added to zone counters */
341                         z = n + os;
342                         n = -os;
343                 }
344         } while (this_cpu_cmpxchg(*p, o, n) != o);
345 
346         if (z)
347                 zone_page_state_add(z, zone, item);
348 }
349 
350 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
351                                         int delta)
352 {
353         mod_state(zone, item, delta, 0);
354 }
355 EXPORT_SYMBOL(mod_zone_page_state);
356 
357 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
358 {
359         mod_state(zone, item, 1, 1);
360 }
361 
362 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
363 {
364         mod_state(page_zone(page), item, 1, 1);
365 }
366 EXPORT_SYMBOL(inc_zone_page_state);
367 
368 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
369 {
370         mod_state(page_zone(page), item, -1, -1);
371 }
372 EXPORT_SYMBOL(dec_zone_page_state);
373 #else
374 /*
375  * Use interrupt disable to serialize counter updates
376  */
377 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
378                                         int delta)
379 {
380         unsigned long flags;
381 
382         local_irq_save(flags);
383         __mod_zone_page_state(zone, item, delta);
384         local_irq_restore(flags);
385 }
386 EXPORT_SYMBOL(mod_zone_page_state);
387 
388 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
389 {
390         unsigned long flags;
391 
392         local_irq_save(flags);
393         __inc_zone_state(zone, item);
394         local_irq_restore(flags);
395 }
396 
397 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
398 {
399         unsigned long flags;
400         struct zone *zone;
401 
402         zone = page_zone(page);
403         local_irq_save(flags);
404         __inc_zone_state(zone, item);
405         local_irq_restore(flags);
406 }
407 EXPORT_SYMBOL(inc_zone_page_state);
408 
409 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
410 {
411         unsigned long flags;
412 
413         local_irq_save(flags);
414         __dec_zone_page_state(page, item);
415         local_irq_restore(flags);
416 }
417 EXPORT_SYMBOL(dec_zone_page_state);
418 #endif
419 
420 static inline void fold_diff(int *diff)
421 {
422         int i;
423 
424         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
425                 if (diff[i])
426                         atomic_long_add(diff[i], &vm_stat[i]);
427 }
428 
429 /*
430  * Update the zone counters for the current cpu.
431  *
432  * Note that refresh_cpu_vm_stats strives to only access
433  * node local memory. The per cpu pagesets on remote zones are placed
434  * in the memory local to the processor using that pageset. So the
435  * loop over all zones will access a series of cachelines local to
436  * the processor.
437  *
438  * The call to zone_page_state_add updates the cachelines with the
439  * statistics in the remote zone struct as well as the global cachelines
440  * with the global counters. These could cause remote node cache line
441  * bouncing and will have to be only done when necessary.
442  */
443 static void refresh_cpu_vm_stats(void)
444 {
445         struct zone *zone;
446         int i;
447         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
448 
449         for_each_populated_zone(zone) {
450                 struct per_cpu_pageset __percpu *p = zone->pageset;
451 
452                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
453                         int v;
454 
455                         v = this_cpu_xchg(p->vm_stat_diff[i], 0);
456                         if (v) {
457 
458                                 atomic_long_add(v, &zone->vm_stat[i]);
459                                 global_diff[i] += v;
460 #ifdef CONFIG_NUMA
461                                 /* 3 seconds idle till flush */
462                                 __this_cpu_write(p->expire, 3);
463 #endif
464                         }
465                 }
466                 cond_resched();
467 #ifdef CONFIG_NUMA
468                 /*
469                  * Deal with draining the remote pageset of this
470                  * processor
471                  *
472                  * Check if there are pages remaining in this pageset
473                  * if not then there is nothing to expire.
474                  */
475                 if (!__this_cpu_read(p->expire) ||
476                                !__this_cpu_read(p->pcp.count))
477                         continue;
478 
479                 /*
480                  * We never drain zones local to this processor.
481                  */
482                 if (zone_to_nid(zone) == numa_node_id()) {
483                         __this_cpu_write(p->expire, 0);
484                         continue;
485                 }
486 
487 
488                 if (__this_cpu_dec_return(p->expire))
489                         continue;
490 
491                 if (__this_cpu_read(p->pcp.count))
492                         drain_zone_pages(zone, __this_cpu_ptr(&p->pcp));
493 #endif
494         }
495         fold_diff(global_diff);
496 }
497 
498 /*
499  * Fold the data for an offline cpu into the global array.
500  * There cannot be any access by the offline cpu and therefore
501  * synchronization is simplified.
502  */
503 void cpu_vm_stats_fold(int cpu)
504 {
505         struct zone *zone;
506         int i;
507         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
508 
509         for_each_populated_zone(zone) {
510                 struct per_cpu_pageset *p;
511 
512                 p = per_cpu_ptr(zone->pageset, cpu);
513 
514                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
515                         if (p->vm_stat_diff[i]) {
516                                 int v;
517 
518                                 v = p->vm_stat_diff[i];
519                                 p->vm_stat_diff[i] = 0;
520                                 atomic_long_add(v, &zone->vm_stat[i]);
521                                 global_diff[i] += v;
522                         }
523         }
524 
525         fold_diff(global_diff);
526 }
527 
528 /*
529  * this is only called if !populated_zone(zone), which implies no other users of
530  * pset->vm_stat_diff[] exsist.
531  */
532 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
533 {
534         int i;
535 
536         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
537                 if (pset->vm_stat_diff[i]) {
538                         int v = pset->vm_stat_diff[i];
539                         pset->vm_stat_diff[i] = 0;
540                         atomic_long_add(v, &zone->vm_stat[i]);
541                         atomic_long_add(v, &vm_stat[i]);
542                 }
543 }
544 #endif
545 
546 #ifdef CONFIG_NUMA
547 /*
548  * zonelist = the list of zones passed to the allocator
549  * z        = the zone from which the allocation occurred.
550  *
551  * Must be called with interrupts disabled.
552  *
553  * When __GFP_OTHER_NODE is set assume the node of the preferred
554  * zone is the local node. This is useful for daemons who allocate
555  * memory on behalf of other processes.
556  */
557 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
558 {
559         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
560                 __inc_zone_state(z, NUMA_HIT);
561         } else {
562                 __inc_zone_state(z, NUMA_MISS);
563                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
564         }
565         if (z->node == ((flags & __GFP_OTHER_NODE) ?
566                         preferred_zone->node : numa_node_id()))
567                 __inc_zone_state(z, NUMA_LOCAL);
568         else
569                 __inc_zone_state(z, NUMA_OTHER);
570 }
571 #endif
572 
573 #ifdef CONFIG_COMPACTION
574 
575 struct contig_page_info {
576         unsigned long free_pages;
577         unsigned long free_blocks_total;
578         unsigned long free_blocks_suitable;
579 };
580 
581 /*
582  * Calculate the number of free pages in a zone, how many contiguous
583  * pages are free and how many are large enough to satisfy an allocation of
584  * the target size. Note that this function makes no attempt to estimate
585  * how many suitable free blocks there *might* be if MOVABLE pages were
586  * migrated. Calculating that is possible, but expensive and can be
587  * figured out from userspace
588  */
589 static void fill_contig_page_info(struct zone *zone,
590                                 unsigned int suitable_order,
591                                 struct contig_page_info *info)
592 {
593         unsigned int order;
594 
595         info->free_pages = 0;
596         info->free_blocks_total = 0;
597         info->free_blocks_suitable = 0;
598 
599         for (order = 0; order < MAX_ORDER; order++) {
600                 unsigned long blocks;
601 
602                 /* Count number of free blocks */
603                 blocks = zone->free_area[order].nr_free;
604                 info->free_blocks_total += blocks;
605 
606                 /* Count free base pages */
607                 info->free_pages += blocks << order;
608 
609                 /* Count the suitable free blocks */
610                 if (order >= suitable_order)
611                         info->free_blocks_suitable += blocks <<
612                                                 (order - suitable_order);
613         }
614 }
615 
616 /*
617  * A fragmentation index only makes sense if an allocation of a requested
618  * size would fail. If that is true, the fragmentation index indicates
619  * whether external fragmentation or a lack of memory was the problem.
620  * The value can be used to determine if page reclaim or compaction
621  * should be used
622  */
623 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
624 {
625         unsigned long requested = 1UL << order;
626 
627         if (!info->free_blocks_total)
628                 return 0;
629 
630         /* Fragmentation index only makes sense when a request would fail */
631         if (info->free_blocks_suitable)
632                 return -1000;
633 
634         /*
635          * Index is between 0 and 1 so return within 3 decimal places
636          *
637          * 0 => allocation would fail due to lack of memory
638          * 1 => allocation would fail due to fragmentation
639          */
640         return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
641 }
642 
643 /* Same as __fragmentation index but allocs contig_page_info on stack */
644 int fragmentation_index(struct zone *zone, unsigned int order)
645 {
646         struct contig_page_info info;
647 
648         fill_contig_page_info(zone, order, &info);
649         return __fragmentation_index(order, &info);
650 }
651 #endif
652 
653 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
654 #include <linux/proc_fs.h>
655 #include <linux/seq_file.h>
656 
657 static char * const migratetype_names[MIGRATE_TYPES] = {
658         "Unmovable",
659         "Reclaimable",
660         "Movable",
661         "Reserve",
662 #ifdef CONFIG_CMA
663         "CMA",
664 #endif
665 #ifdef CONFIG_MEMORY_ISOLATION
666         "Isolate",
667 #endif
668 };
669 
670 static void *frag_start(struct seq_file *m, loff_t *pos)
671 {
672         pg_data_t *pgdat;
673         loff_t node = *pos;
674         for (pgdat = first_online_pgdat();
675              pgdat && node;
676              pgdat = next_online_pgdat(pgdat))
677                 --node;
678 
679         return pgdat;
680 }
681 
682 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
683 {
684         pg_data_t *pgdat = (pg_data_t *)arg;
685 
686         (*pos)++;
687         return next_online_pgdat(pgdat);
688 }
689 
690 static void frag_stop(struct seq_file *m, void *arg)
691 {
692 }
693 
694 /* Walk all the zones in a node and print using a callback */
695 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
696                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
697 {
698         struct zone *zone;
699         struct zone *node_zones = pgdat->node_zones;
700         unsigned long flags;
701 
702         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
703                 if (!populated_zone(zone))
704                         continue;
705 
706                 spin_lock_irqsave(&zone->lock, flags);
707                 print(m, pgdat, zone);
708                 spin_unlock_irqrestore(&zone->lock, flags);
709         }
710 }
711 #endif
712 
713 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
714 #ifdef CONFIG_ZONE_DMA
715 #define TEXT_FOR_DMA(xx) xx "_dma",
716 #else
717 #define TEXT_FOR_DMA(xx)
718 #endif
719 
720 #ifdef CONFIG_ZONE_DMA32
721 #define TEXT_FOR_DMA32(xx) xx "_dma32",
722 #else
723 #define TEXT_FOR_DMA32(xx)
724 #endif
725 
726 #ifdef CONFIG_HIGHMEM
727 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
728 #else
729 #define TEXT_FOR_HIGHMEM(xx)
730 #endif
731 
732 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
733                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
734 
735 const char * const vmstat_text[] = {
736         /* Zoned VM counters */
737         "nr_free_pages",
738         "nr_alloc_batch",
739         "nr_inactive_anon",
740         "nr_active_anon",
741         "nr_inactive_file",
742         "nr_active_file",
743         "nr_unevictable",
744         "nr_mlock",
745         "nr_anon_pages",
746         "nr_mapped",
747         "nr_file_pages",
748         "nr_dirty",
749         "nr_writeback",
750         "nr_slab_reclaimable",
751         "nr_slab_unreclaimable",
752         "nr_page_table_pages",
753         "nr_kernel_stack",
754         "nr_unstable",
755         "nr_bounce",
756         "nr_vmscan_write",
757         "nr_vmscan_immediate_reclaim",
758         "nr_writeback_temp",
759         "nr_isolated_anon",
760         "nr_isolated_file",
761         "nr_shmem",
762         "nr_dirtied",
763         "nr_written",
764         "nr_pages_scanned",
765 
766 #ifdef CONFIG_NUMA
767         "numa_hit",
768         "numa_miss",
769         "numa_foreign",
770         "numa_interleave",
771         "numa_local",
772         "numa_other",
773 #endif
774         "nr_anon_transparent_hugepages",
775         "nr_free_cma",
776         "nr_dirty_threshold",
777         "nr_dirty_background_threshold",
778 
779 #ifdef CONFIG_VM_EVENT_COUNTERS
780         "pgpgin",
781         "pgpgout",
782         "pswpin",
783         "pswpout",
784 
785         TEXTS_FOR_ZONES("pgalloc")
786 
787         "pgfree",
788         "pgactivate",
789         "pgdeactivate",
790 
791         "pgfault",
792         "pgmajfault",
793 
794         TEXTS_FOR_ZONES("pgrefill")
795         TEXTS_FOR_ZONES("pgsteal_kswapd")
796         TEXTS_FOR_ZONES("pgsteal_direct")
797         TEXTS_FOR_ZONES("pgscan_kswapd")
798         TEXTS_FOR_ZONES("pgscan_direct")
799         "pgscan_direct_throttle",
800 
801 #ifdef CONFIG_NUMA
802         "zone_reclaim_failed",
803 #endif
804         "pginodesteal",
805         "slabs_scanned",
806         "kswapd_inodesteal",
807         "kswapd_low_wmark_hit_quickly",
808         "kswapd_high_wmark_hit_quickly",
809         "pageoutrun",
810         "allocstall",
811 
812         "pgrotated",
813 
814 #ifdef CONFIG_NUMA_BALANCING
815         "numa_pte_updates",
816         "numa_huge_pte_updates",
817         "numa_hint_faults",
818         "numa_hint_faults_local",
819         "numa_pages_migrated",
820 #endif
821 #ifdef CONFIG_MIGRATION
822         "pgmigrate_success",
823         "pgmigrate_fail",
824 #endif
825 #ifdef CONFIG_COMPACTION
826         "compact_migrate_scanned",
827         "compact_free_scanned",
828         "compact_isolated",
829         "compact_stall",
830         "compact_fail",
831         "compact_success",
832 #endif
833 
834 #ifdef CONFIG_HUGETLB_PAGE
835         "htlb_buddy_alloc_success",
836         "htlb_buddy_alloc_fail",
837 #endif
838         "unevictable_pgs_culled",
839         "unevictable_pgs_scanned",
840         "unevictable_pgs_rescued",
841         "unevictable_pgs_mlocked",
842         "unevictable_pgs_munlocked",
843         "unevictable_pgs_cleared",
844         "unevictable_pgs_stranded",
845 
846 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
847         "thp_fault_alloc",
848         "thp_fault_fallback",
849         "thp_collapse_alloc",
850         "thp_collapse_alloc_failed",
851         "thp_split",
852         "thp_zero_page_alloc",
853         "thp_zero_page_alloc_failed",
854 #endif
855 #ifdef CONFIG_DEBUG_TLBFLUSH
856 #ifdef CONFIG_SMP
857         "nr_tlb_remote_flush",
858         "nr_tlb_remote_flush_received",
859 #endif /* CONFIG_SMP */
860         "nr_tlb_local_flush_all",
861         "nr_tlb_local_flush_one",
862 #endif /* CONFIG_DEBUG_TLBFLUSH */
863 
864 #endif /* CONFIG_VM_EVENTS_COUNTERS */
865 };
866 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
867 
868 
869 #ifdef CONFIG_PROC_FS
870 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
871                                                 struct zone *zone)
872 {
873         int order;
874 
875         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
876         for (order = 0; order < MAX_ORDER; ++order)
877                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
878         seq_putc(m, '\n');
879 }
880 
881 /*
882  * This walks the free areas for each zone.
883  */
884 static int frag_show(struct seq_file *m, void *arg)
885 {
886         pg_data_t *pgdat = (pg_data_t *)arg;
887         walk_zones_in_node(m, pgdat, frag_show_print);
888         return 0;
889 }
890 
891 static void pagetypeinfo_showfree_print(struct seq_file *m,
892                                         pg_data_t *pgdat, struct zone *zone)
893 {
894         int order, mtype;
895 
896         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
897                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
898                                         pgdat->node_id,
899                                         zone->name,
900                                         migratetype_names[mtype]);
901                 for (order = 0; order < MAX_ORDER; ++order) {
902                         unsigned long freecount = 0;
903                         struct free_area *area;
904                         struct list_head *curr;
905 
906                         area = &(zone->free_area[order]);
907 
908                         list_for_each(curr, &area->free_list[mtype])
909                                 freecount++;
910                         seq_printf(m, "%6lu ", freecount);
911                 }
912                 seq_putc(m, '\n');
913         }
914 }
915 
916 /* Print out the free pages at each order for each migatetype */
917 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
918 {
919         int order;
920         pg_data_t *pgdat = (pg_data_t *)arg;
921 
922         /* Print header */
923         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
924         for (order = 0; order < MAX_ORDER; ++order)
925                 seq_printf(m, "%6d ", order);
926         seq_putc(m, '\n');
927 
928         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
929 
930         return 0;
931 }
932 
933 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
934                                         pg_data_t *pgdat, struct zone *zone)
935 {
936         int mtype;
937         unsigned long pfn;
938         unsigned long start_pfn = zone->zone_start_pfn;
939         unsigned long end_pfn = zone_end_pfn(zone);
940         unsigned long count[MIGRATE_TYPES] = { 0, };
941 
942         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
943                 struct page *page;
944 
945                 if (!pfn_valid(pfn))
946                         continue;
947 
948                 page = pfn_to_page(pfn);
949 
950                 /* Watch for unexpected holes punched in the memmap */
951                 if (!memmap_valid_within(pfn, page, zone))
952                         continue;
953 
954                 mtype = get_pageblock_migratetype(page);
955 
956                 if (mtype < MIGRATE_TYPES)
957                         count[mtype]++;
958         }
959 
960         /* Print counts */
961         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
962         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
963                 seq_printf(m, "%12lu ", count[mtype]);
964         seq_putc(m, '\n');
965 }
966 
967 /* Print out the free pages at each order for each migratetype */
968 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
969 {
970         int mtype;
971         pg_data_t *pgdat = (pg_data_t *)arg;
972 
973         seq_printf(m, "\n%-23s", "Number of blocks type ");
974         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
975                 seq_printf(m, "%12s ", migratetype_names[mtype]);
976         seq_putc(m, '\n');
977         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
978 
979         return 0;
980 }
981 
982 /*
983  * This prints out statistics in relation to grouping pages by mobility.
984  * It is expensive to collect so do not constantly read the file.
985  */
986 static int pagetypeinfo_show(struct seq_file *m, void *arg)
987 {
988         pg_data_t *pgdat = (pg_data_t *)arg;
989 
990         /* check memoryless node */
991         if (!node_state(pgdat->node_id, N_MEMORY))
992                 return 0;
993 
994         seq_printf(m, "Page block order: %d\n", pageblock_order);
995         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
996         seq_putc(m, '\n');
997         pagetypeinfo_showfree(m, pgdat);
998         pagetypeinfo_showblockcount(m, pgdat);
999 
1000         return 0;
1001 }
1002 
1003 static const struct seq_operations fragmentation_op = {
1004         .start  = frag_start,
1005         .next   = frag_next,
1006         .stop   = frag_stop,
1007         .show   = frag_show,
1008 };
1009 
1010 static int fragmentation_open(struct inode *inode, struct file *file)
1011 {
1012         return seq_open(file, &fragmentation_op);
1013 }
1014 
1015 static const struct file_operations fragmentation_file_operations = {
1016         .open           = fragmentation_open,
1017         .read           = seq_read,
1018         .llseek         = seq_lseek,
1019         .release        = seq_release,
1020 };
1021 
1022 static const struct seq_operations pagetypeinfo_op = {
1023         .start  = frag_start,
1024         .next   = frag_next,
1025         .stop   = frag_stop,
1026         .show   = pagetypeinfo_show,
1027 };
1028 
1029 static int pagetypeinfo_open(struct inode *inode, struct file *file)
1030 {
1031         return seq_open(file, &pagetypeinfo_op);
1032 }
1033 
1034 static const struct file_operations pagetypeinfo_file_ops = {
1035         .open           = pagetypeinfo_open,
1036         .read           = seq_read,
1037         .llseek         = seq_lseek,
1038         .release        = seq_release,
1039 };
1040 
1041 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1042                                                         struct zone *zone)
1043 {
1044         int i;
1045         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1046         seq_printf(m,
1047                    "\n  pages free     %lu"
1048                    "\n        min      %lu"
1049                    "\n        low      %lu"
1050                    "\n        high     %lu"
1051                    "\n        scanned  %lu"
1052                    "\n        spanned  %lu"
1053                    "\n        present  %lu"
1054                    "\n        managed  %lu",
1055                    zone_page_state(zone, NR_FREE_PAGES),
1056                    min_wmark_pages(zone),
1057                    low_wmark_pages(zone),
1058                    high_wmark_pages(zone),
1059                    zone_page_state(zone, NR_PAGES_SCANNED),
1060                    zone->spanned_pages,
1061                    zone->present_pages,
1062                    zone->managed_pages);
1063 
1064         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1065                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
1066                                 zone_page_state(zone, i));
1067 
1068         seq_printf(m,
1069                    "\n        protection: (%ld",
1070                    zone->lowmem_reserve[0]);
1071         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1072                 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1073         seq_printf(m,
1074                    ")"
1075                    "\n  pagesets");
1076         for_each_online_cpu(i) {
1077                 struct per_cpu_pageset *pageset;
1078 
1079                 pageset = per_cpu_ptr(zone->pageset, i);
1080                 seq_printf(m,
1081                            "\n    cpu: %i"
1082                            "\n              count: %i"
1083                            "\n              high:  %i"
1084                            "\n              batch: %i",
1085                            i,
1086                            pageset->pcp.count,
1087                            pageset->pcp.high,
1088                            pageset->pcp.batch);
1089 #ifdef CONFIG_SMP
1090                 seq_printf(m, "\n  vm stats threshold: %d",
1091                                 pageset->stat_threshold);
1092 #endif
1093         }
1094         seq_printf(m,
1095                    "\n  all_unreclaimable: %u"
1096                    "\n  start_pfn:         %lu"
1097                    "\n  inactive_ratio:    %u",
1098                    !zone_reclaimable(zone),
1099                    zone->zone_start_pfn,
1100                    zone->inactive_ratio);
1101         seq_putc(m, '\n');
1102 }
1103 
1104 /*
1105  * Output information about zones in @pgdat.
1106  */
1107 static int zoneinfo_show(struct seq_file *m, void *arg)
1108 {
1109         pg_data_t *pgdat = (pg_data_t *)arg;
1110         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1111         return 0;
1112 }
1113 
1114 static const struct seq_operations zoneinfo_op = {
1115         .start  = frag_start, /* iterate over all zones. The same as in
1116                                * fragmentation. */
1117         .next   = frag_next,
1118         .stop   = frag_stop,
1119         .show   = zoneinfo_show,
1120 };
1121 
1122 static int zoneinfo_open(struct inode *inode, struct file *file)
1123 {
1124         return seq_open(file, &zoneinfo_op);
1125 }
1126 
1127 static const struct file_operations proc_zoneinfo_file_operations = {
1128         .open           = zoneinfo_open,
1129         .read           = seq_read,
1130         .llseek         = seq_lseek,
1131         .release        = seq_release,
1132 };
1133 
1134 enum writeback_stat_item {
1135         NR_DIRTY_THRESHOLD,
1136         NR_DIRTY_BG_THRESHOLD,
1137         NR_VM_WRITEBACK_STAT_ITEMS,
1138 };
1139 
1140 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1141 {
1142         unsigned long *v;
1143         int i, stat_items_size;
1144 
1145         if (*pos >= ARRAY_SIZE(vmstat_text))
1146                 return NULL;
1147         stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1148                           NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1149 
1150 #ifdef CONFIG_VM_EVENT_COUNTERS
1151         stat_items_size += sizeof(struct vm_event_state);
1152 #endif
1153 
1154         v = kmalloc(stat_items_size, GFP_KERNEL);
1155         m->private = v;
1156         if (!v)
1157                 return ERR_PTR(-ENOMEM);
1158         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1159                 v[i] = global_page_state(i);
1160         v += NR_VM_ZONE_STAT_ITEMS;
1161 
1162         global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1163                             v + NR_DIRTY_THRESHOLD);
1164         v += NR_VM_WRITEBACK_STAT_ITEMS;
1165 
1166 #ifdef CONFIG_VM_EVENT_COUNTERS
1167         all_vm_events(v);
1168         v[PGPGIN] /= 2;         /* sectors -> kbytes */
1169         v[PGPGOUT] /= 2;
1170 #endif
1171         return (unsigned long *)m->private + *pos;
1172 }
1173 
1174 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1175 {
1176         (*pos)++;
1177         if (*pos >= ARRAY_SIZE(vmstat_text))
1178                 return NULL;
1179         return (unsigned long *)m->private + *pos;
1180 }
1181 
1182 static int vmstat_show(struct seq_file *m, void *arg)
1183 {
1184         unsigned long *l = arg;
1185         unsigned long off = l - (unsigned long *)m->private;
1186 
1187         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1188         return 0;
1189 }
1190 
1191 static void vmstat_stop(struct seq_file *m, void *arg)
1192 {
1193         kfree(m->private);
1194         m->private = NULL;
1195 }
1196 
1197 static const struct seq_operations vmstat_op = {
1198         .start  = vmstat_start,
1199         .next   = vmstat_next,
1200         .stop   = vmstat_stop,
1201         .show   = vmstat_show,
1202 };
1203 
1204 static int vmstat_open(struct inode *inode, struct file *file)
1205 {
1206         return seq_open(file, &vmstat_op);
1207 }
1208 
1209 static const struct file_operations proc_vmstat_file_operations = {
1210         .open           = vmstat_open,
1211         .read           = seq_read,
1212         .llseek         = seq_lseek,
1213         .release        = seq_release,
1214 };
1215 #endif /* CONFIG_PROC_FS */
1216 
1217 #ifdef CONFIG_SMP
1218 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1219 int sysctl_stat_interval __read_mostly = HZ;
1220 
1221 static void vmstat_update(struct work_struct *w)
1222 {
1223         refresh_cpu_vm_stats();
1224         schedule_delayed_work(&__get_cpu_var(vmstat_work),
1225                 round_jiffies_relative(sysctl_stat_interval));
1226 }
1227 
1228 static void start_cpu_timer(int cpu)
1229 {
1230         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1231 
1232         INIT_DEFERRABLE_WORK(work, vmstat_update);
1233         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1234 }
1235 
1236 static void vmstat_cpu_dead(int node)
1237 {
1238         int cpu;
1239 
1240         get_online_cpus();
1241         for_each_online_cpu(cpu)
1242                 if (cpu_to_node(cpu) == node)
1243                         goto end;
1244 
1245         node_clear_state(node, N_CPU);
1246 end:
1247         put_online_cpus();
1248 }
1249 
1250 /*
1251  * Use the cpu notifier to insure that the thresholds are recalculated
1252  * when necessary.
1253  */
1254 static int vmstat_cpuup_callback(struct notifier_block *nfb,
1255                 unsigned long action,
1256                 void *hcpu)
1257 {
1258         long cpu = (long)hcpu;
1259 
1260         switch (action) {
1261         case CPU_ONLINE:
1262         case CPU_ONLINE_FROZEN:
1263                 refresh_zone_stat_thresholds();
1264                 start_cpu_timer(cpu);
1265                 node_set_state(cpu_to_node(cpu), N_CPU);
1266                 break;
1267         case CPU_DOWN_PREPARE:
1268         case CPU_DOWN_PREPARE_FROZEN:
1269                 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1270                 per_cpu(vmstat_work, cpu).work.func = NULL;
1271                 break;
1272         case CPU_DOWN_FAILED:
1273         case CPU_DOWN_FAILED_FROZEN:
1274                 start_cpu_timer(cpu);
1275                 break;
1276         case CPU_DEAD:
1277         case CPU_DEAD_FROZEN:
1278                 refresh_zone_stat_thresholds();
1279                 vmstat_cpu_dead(cpu_to_node(cpu));
1280                 break;
1281         default:
1282                 break;
1283         }
1284         return NOTIFY_OK;
1285 }
1286 
1287 static struct notifier_block vmstat_notifier =
1288         { &vmstat_cpuup_callback, NULL, 0 };
1289 #endif
1290 
1291 static int __init setup_vmstat(void)
1292 {
1293 #ifdef CONFIG_SMP
1294         int cpu;
1295 
1296         register_cpu_notifier(&vmstat_notifier);
1297 
1298         get_online_cpus();
1299         for_each_online_cpu(cpu) {
1300                 start_cpu_timer(cpu);
1301                 node_set_state(cpu_to_node(cpu), N_CPU);
1302         }
1303         put_online_cpus();
1304 #endif
1305 #ifdef CONFIG_PROC_FS
1306         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1307         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1308         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1309         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1310 #endif
1311         return 0;
1312 }
1313 module_init(setup_vmstat)
1314 
1315 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1316 #include <linux/debugfs.h>
1317 
1318 
1319 /*
1320  * Return an index indicating how much of the available free memory is
1321  * unusable for an allocation of the requested size.
1322  */
1323 static int unusable_free_index(unsigned int order,
1324                                 struct contig_page_info *info)
1325 {
1326         /* No free memory is interpreted as all free memory is unusable */
1327         if (info->free_pages == 0)
1328                 return 1000;
1329 
1330         /*
1331          * Index should be a value between 0 and 1. Return a value to 3
1332          * decimal places.
1333          *
1334          * 0 => no fragmentation
1335          * 1 => high fragmentation
1336          */
1337         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1338 
1339 }
1340 
1341 static void unusable_show_print(struct seq_file *m,
1342                                         pg_data_t *pgdat, struct zone *zone)
1343 {
1344         unsigned int order;
1345         int index;
1346         struct contig_page_info info;
1347 
1348         seq_printf(m, "Node %d, zone %8s ",
1349                                 pgdat->node_id,
1350                                 zone->name);
1351         for (order = 0; order < MAX_ORDER; ++order) {
1352                 fill_contig_page_info(zone, order, &info);
1353                 index = unusable_free_index(order, &info);
1354                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1355         }
1356 
1357         seq_putc(m, '\n');
1358 }
1359 
1360 /*
1361  * Display unusable free space index
1362  *
1363  * The unusable free space index measures how much of the available free
1364  * memory cannot be used to satisfy an allocation of a given size and is a
1365  * value between 0 and 1. The higher the value, the more of free memory is
1366  * unusable and by implication, the worse the external fragmentation is. This
1367  * can be expressed as a percentage by multiplying by 100.
1368  */
1369 static int unusable_show(struct seq_file *m, void *arg)
1370 {
1371         pg_data_t *pgdat = (pg_data_t *)arg;
1372 
1373         /* check memoryless node */
1374         if (!node_state(pgdat->node_id, N_MEMORY))
1375                 return 0;
1376 
1377         walk_zones_in_node(m, pgdat, unusable_show_print);
1378 
1379         return 0;
1380 }
1381 
1382 static const struct seq_operations unusable_op = {
1383         .start  = frag_start,
1384         .next   = frag_next,
1385         .stop   = frag_stop,
1386         .show   = unusable_show,
1387 };
1388 
1389 static int unusable_open(struct inode *inode, struct file *file)
1390 {
1391         return seq_open(file, &unusable_op);
1392 }
1393 
1394 static const struct file_operations unusable_file_ops = {
1395         .open           = unusable_open,
1396         .read           = seq_read,
1397         .llseek         = seq_lseek,
1398         .release        = seq_release,
1399 };
1400 
1401 static void extfrag_show_print(struct seq_file *m,
1402                                         pg_data_t *pgdat, struct zone *zone)
1403 {
1404         unsigned int order;
1405         int index;
1406 
1407         /* Alloc on stack as interrupts are disabled for zone walk */
1408         struct contig_page_info info;
1409 
1410         seq_printf(m, "Node %d, zone %8s ",
1411                                 pgdat->node_id,
1412                                 zone->name);
1413         for (order = 0; order < MAX_ORDER; ++order) {
1414                 fill_contig_page_info(zone, order, &info);
1415                 index = __fragmentation_index(order, &info);
1416                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1417         }
1418 
1419         seq_putc(m, '\n');
1420 }
1421 
1422 /*
1423  * Display fragmentation index for orders that allocations would fail for
1424  */
1425 static int extfrag_show(struct seq_file *m, void *arg)
1426 {
1427         pg_data_t *pgdat = (pg_data_t *)arg;
1428 
1429         walk_zones_in_node(m, pgdat, extfrag_show_print);
1430 
1431         return 0;
1432 }
1433 
1434 static const struct seq_operations extfrag_op = {
1435         .start  = frag_start,
1436         .next   = frag_next,
1437         .stop   = frag_stop,
1438         .show   = extfrag_show,
1439 };
1440 
1441 static int extfrag_open(struct inode *inode, struct file *file)
1442 {
1443         return seq_open(file, &extfrag_op);
1444 }
1445 
1446 static const struct file_operations extfrag_file_ops = {
1447         .open           = extfrag_open,
1448         .read           = seq_read,
1449         .llseek         = seq_lseek,
1450         .release        = seq_release,
1451 };
1452 
1453 static int __init extfrag_debug_init(void)
1454 {
1455         struct dentry *extfrag_debug_root;
1456 
1457         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1458         if (!extfrag_debug_root)
1459                 return -ENOMEM;
1460 
1461         if (!debugfs_create_file("unusable_index", 0444,
1462                         extfrag_debug_root, NULL, &unusable_file_ops))
1463                 goto fail;
1464 
1465         if (!debugfs_create_file("extfrag_index", 0444,
1466                         extfrag_debug_root, NULL, &extfrag_file_ops))
1467                 goto fail;
1468 
1469         return 0;
1470 fail:
1471         debugfs_remove_recursive(extfrag_debug_root);
1472         return -ENOMEM;
1473 }
1474 
1475 module_init(extfrag_debug_init);
1476 #endif
1477 

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