Merge remote-tracking branch 'asoc/fix/wm8962' into asoc-linus
[platform/adaptation/renesas_rcar/renesas_kernel.git] / 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 #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_possible_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
765 #ifdef CONFIG_NUMA
766         "numa_hit",
767         "numa_miss",
768         "numa_foreign",
769         "numa_interleave",
770         "numa_local",
771         "numa_other",
772 #endif
773         "nr_anon_transparent_hugepages",
774         "nr_free_cma",
775         "nr_dirty_threshold",
776         "nr_dirty_background_threshold",
777
778 #ifdef CONFIG_VM_EVENT_COUNTERS
779         "pgpgin",
780         "pgpgout",
781         "pswpin",
782         "pswpout",
783
784         TEXTS_FOR_ZONES("pgalloc")
785
786         "pgfree",
787         "pgactivate",
788         "pgdeactivate",
789
790         "pgfault",
791         "pgmajfault",
792
793         TEXTS_FOR_ZONES("pgrefill")
794         TEXTS_FOR_ZONES("pgsteal_kswapd")
795         TEXTS_FOR_ZONES("pgsteal_direct")
796         TEXTS_FOR_ZONES("pgscan_kswapd")
797         TEXTS_FOR_ZONES("pgscan_direct")
798         "pgscan_direct_throttle",
799
800 #ifdef CONFIG_NUMA
801         "zone_reclaim_failed",
802 #endif
803         "pginodesteal",
804         "slabs_scanned",
805         "kswapd_inodesteal",
806         "kswapd_low_wmark_hit_quickly",
807         "kswapd_high_wmark_hit_quickly",
808         "pageoutrun",
809         "allocstall",
810
811         "pgrotated",
812
813 #ifdef CONFIG_NUMA_BALANCING
814         "numa_pte_updates",
815         "numa_hint_faults",
816         "numa_hint_faults_local",
817         "numa_pages_migrated",
818 #endif
819 #ifdef CONFIG_MIGRATION
820         "pgmigrate_success",
821         "pgmigrate_fail",
822 #endif
823 #ifdef CONFIG_COMPACTION
824         "compact_migrate_scanned",
825         "compact_free_scanned",
826         "compact_isolated",
827         "compact_stall",
828         "compact_fail",
829         "compact_success",
830 #endif
831
832 #ifdef CONFIG_HUGETLB_PAGE
833         "htlb_buddy_alloc_success",
834         "htlb_buddy_alloc_fail",
835 #endif
836         "unevictable_pgs_culled",
837         "unevictable_pgs_scanned",
838         "unevictable_pgs_rescued",
839         "unevictable_pgs_mlocked",
840         "unevictable_pgs_munlocked",
841         "unevictable_pgs_cleared",
842         "unevictable_pgs_stranded",
843
844 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
845         "thp_fault_alloc",
846         "thp_fault_fallback",
847         "thp_collapse_alloc",
848         "thp_collapse_alloc_failed",
849         "thp_split",
850         "thp_zero_page_alloc",
851         "thp_zero_page_alloc_failed",
852 #endif
853 #ifdef CONFIG_SMP
854         "nr_tlb_remote_flush",
855         "nr_tlb_remote_flush_received",
856 #endif
857         "nr_tlb_local_flush_all",
858         "nr_tlb_local_flush_one",
859
860 #endif /* CONFIG_VM_EVENTS_COUNTERS */
861 };
862 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
863
864
865 #ifdef CONFIG_PROC_FS
866 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
867                                                 struct zone *zone)
868 {
869         int order;
870
871         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
872         for (order = 0; order < MAX_ORDER; ++order)
873                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
874         seq_putc(m, '\n');
875 }
876
877 /*
878  * This walks the free areas for each zone.
879  */
880 static int frag_show(struct seq_file *m, void *arg)
881 {
882         pg_data_t *pgdat = (pg_data_t *)arg;
883         walk_zones_in_node(m, pgdat, frag_show_print);
884         return 0;
885 }
886
887 static void pagetypeinfo_showfree_print(struct seq_file *m,
888                                         pg_data_t *pgdat, struct zone *zone)
889 {
890         int order, mtype;
891
892         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
893                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
894                                         pgdat->node_id,
895                                         zone->name,
896                                         migratetype_names[mtype]);
897                 for (order = 0; order < MAX_ORDER; ++order) {
898                         unsigned long freecount = 0;
899                         struct free_area *area;
900                         struct list_head *curr;
901
902                         area = &(zone->free_area[order]);
903
904                         list_for_each(curr, &area->free_list[mtype])
905                                 freecount++;
906                         seq_printf(m, "%6lu ", freecount);
907                 }
908                 seq_putc(m, '\n');
909         }
910 }
911
912 /* Print out the free pages at each order for each migatetype */
913 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
914 {
915         int order;
916         pg_data_t *pgdat = (pg_data_t *)arg;
917
918         /* Print header */
919         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
920         for (order = 0; order < MAX_ORDER; ++order)
921                 seq_printf(m, "%6d ", order);
922         seq_putc(m, '\n');
923
924         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
925
926         return 0;
927 }
928
929 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
930                                         pg_data_t *pgdat, struct zone *zone)
931 {
932         int mtype;
933         unsigned long pfn;
934         unsigned long start_pfn = zone->zone_start_pfn;
935         unsigned long end_pfn = zone_end_pfn(zone);
936         unsigned long count[MIGRATE_TYPES] = { 0, };
937
938         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
939                 struct page *page;
940
941                 if (!pfn_valid(pfn))
942                         continue;
943
944                 page = pfn_to_page(pfn);
945
946                 /* Watch for unexpected holes punched in the memmap */
947                 if (!memmap_valid_within(pfn, page, zone))
948                         continue;
949
950                 mtype = get_pageblock_migratetype(page);
951
952                 if (mtype < MIGRATE_TYPES)
953                         count[mtype]++;
954         }
955
956         /* Print counts */
957         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
958         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
959                 seq_printf(m, "%12lu ", count[mtype]);
960         seq_putc(m, '\n');
961 }
962
963 /* Print out the free pages at each order for each migratetype */
964 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
965 {
966         int mtype;
967         pg_data_t *pgdat = (pg_data_t *)arg;
968
969         seq_printf(m, "\n%-23s", "Number of blocks type ");
970         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
971                 seq_printf(m, "%12s ", migratetype_names[mtype]);
972         seq_putc(m, '\n');
973         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
974
975         return 0;
976 }
977
978 /*
979  * This prints out statistics in relation to grouping pages by mobility.
980  * It is expensive to collect so do not constantly read the file.
981  */
982 static int pagetypeinfo_show(struct seq_file *m, void *arg)
983 {
984         pg_data_t *pgdat = (pg_data_t *)arg;
985
986         /* check memoryless node */
987         if (!node_state(pgdat->node_id, N_MEMORY))
988                 return 0;
989
990         seq_printf(m, "Page block order: %d\n", pageblock_order);
991         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
992         seq_putc(m, '\n');
993         pagetypeinfo_showfree(m, pgdat);
994         pagetypeinfo_showblockcount(m, pgdat);
995
996         return 0;
997 }
998
999 static const struct seq_operations fragmentation_op = {
1000         .start  = frag_start,
1001         .next   = frag_next,
1002         .stop   = frag_stop,
1003         .show   = frag_show,
1004 };
1005
1006 static int fragmentation_open(struct inode *inode, struct file *file)
1007 {
1008         return seq_open(file, &fragmentation_op);
1009 }
1010
1011 static const struct file_operations fragmentation_file_operations = {
1012         .open           = fragmentation_open,
1013         .read           = seq_read,
1014         .llseek         = seq_lseek,
1015         .release        = seq_release,
1016 };
1017
1018 static const struct seq_operations pagetypeinfo_op = {
1019         .start  = frag_start,
1020         .next   = frag_next,
1021         .stop   = frag_stop,
1022         .show   = pagetypeinfo_show,
1023 };
1024
1025 static int pagetypeinfo_open(struct inode *inode, struct file *file)
1026 {
1027         return seq_open(file, &pagetypeinfo_op);
1028 }
1029
1030 static const struct file_operations pagetypeinfo_file_ops = {
1031         .open           = pagetypeinfo_open,
1032         .read           = seq_read,
1033         .llseek         = seq_lseek,
1034         .release        = seq_release,
1035 };
1036
1037 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1038                                                         struct zone *zone)
1039 {
1040         int i;
1041         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1042         seq_printf(m,
1043                    "\n  pages free     %lu"
1044                    "\n        min      %lu"
1045                    "\n        low      %lu"
1046                    "\n        high     %lu"
1047                    "\n        scanned  %lu"
1048                    "\n        spanned  %lu"
1049                    "\n        present  %lu"
1050                    "\n        managed  %lu",
1051                    zone_page_state(zone, NR_FREE_PAGES),
1052                    min_wmark_pages(zone),
1053                    low_wmark_pages(zone),
1054                    high_wmark_pages(zone),
1055                    zone->pages_scanned,
1056                    zone->spanned_pages,
1057                    zone->present_pages,
1058                    zone->managed_pages);
1059
1060         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1061                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
1062                                 zone_page_state(zone, i));
1063
1064         seq_printf(m,
1065                    "\n        protection: (%lu",
1066                    zone->lowmem_reserve[0]);
1067         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1068                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
1069         seq_printf(m,
1070                    ")"
1071                    "\n  pagesets");
1072         for_each_online_cpu(i) {
1073                 struct per_cpu_pageset *pageset;
1074
1075                 pageset = per_cpu_ptr(zone->pageset, i);
1076                 seq_printf(m,
1077                            "\n    cpu: %i"
1078                            "\n              count: %i"
1079                            "\n              high:  %i"
1080                            "\n              batch: %i",
1081                            i,
1082                            pageset->pcp.count,
1083                            pageset->pcp.high,
1084                            pageset->pcp.batch);
1085 #ifdef CONFIG_SMP
1086                 seq_printf(m, "\n  vm stats threshold: %d",
1087                                 pageset->stat_threshold);
1088 #endif
1089         }
1090         seq_printf(m,
1091                    "\n  all_unreclaimable: %u"
1092                    "\n  start_pfn:         %lu"
1093                    "\n  inactive_ratio:    %u",
1094                    !zone_reclaimable(zone),
1095                    zone->zone_start_pfn,
1096                    zone->inactive_ratio);
1097         seq_putc(m, '\n');
1098 }
1099
1100 /*
1101  * Output information about zones in @pgdat.
1102  */
1103 static int zoneinfo_show(struct seq_file *m, void *arg)
1104 {
1105         pg_data_t *pgdat = (pg_data_t *)arg;
1106         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1107         return 0;
1108 }
1109
1110 static const struct seq_operations zoneinfo_op = {
1111         .start  = frag_start, /* iterate over all zones. The same as in
1112                                * fragmentation. */
1113         .next   = frag_next,
1114         .stop   = frag_stop,
1115         .show   = zoneinfo_show,
1116 };
1117
1118 static int zoneinfo_open(struct inode *inode, struct file *file)
1119 {
1120         return seq_open(file, &zoneinfo_op);
1121 }
1122
1123 static const struct file_operations proc_zoneinfo_file_operations = {
1124         .open           = zoneinfo_open,
1125         .read           = seq_read,
1126         .llseek         = seq_lseek,
1127         .release        = seq_release,
1128 };
1129
1130 enum writeback_stat_item {
1131         NR_DIRTY_THRESHOLD,
1132         NR_DIRTY_BG_THRESHOLD,
1133         NR_VM_WRITEBACK_STAT_ITEMS,
1134 };
1135
1136 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1137 {
1138         unsigned long *v;
1139         int i, stat_items_size;
1140
1141         if (*pos >= ARRAY_SIZE(vmstat_text))
1142                 return NULL;
1143         stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1144                           NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1145
1146 #ifdef CONFIG_VM_EVENT_COUNTERS
1147         stat_items_size += sizeof(struct vm_event_state);
1148 #endif
1149
1150         v = kmalloc(stat_items_size, GFP_KERNEL);
1151         m->private = v;
1152         if (!v)
1153                 return ERR_PTR(-ENOMEM);
1154         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1155                 v[i] = global_page_state(i);
1156         v += NR_VM_ZONE_STAT_ITEMS;
1157
1158         global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1159                             v + NR_DIRTY_THRESHOLD);
1160         v += NR_VM_WRITEBACK_STAT_ITEMS;
1161
1162 #ifdef CONFIG_VM_EVENT_COUNTERS
1163         all_vm_events(v);
1164         v[PGPGIN] /= 2;         /* sectors -> kbytes */
1165         v[PGPGOUT] /= 2;
1166 #endif
1167         return (unsigned long *)m->private + *pos;
1168 }
1169
1170 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1171 {
1172         (*pos)++;
1173         if (*pos >= ARRAY_SIZE(vmstat_text))
1174                 return NULL;
1175         return (unsigned long *)m->private + *pos;
1176 }
1177
1178 static int vmstat_show(struct seq_file *m, void *arg)
1179 {
1180         unsigned long *l = arg;
1181         unsigned long off = l - (unsigned long *)m->private;
1182
1183         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1184         return 0;
1185 }
1186
1187 static void vmstat_stop(struct seq_file *m, void *arg)
1188 {
1189         kfree(m->private);
1190         m->private = NULL;
1191 }
1192
1193 static const struct seq_operations vmstat_op = {
1194         .start  = vmstat_start,
1195         .next   = vmstat_next,
1196         .stop   = vmstat_stop,
1197         .show   = vmstat_show,
1198 };
1199
1200 static int vmstat_open(struct inode *inode, struct file *file)
1201 {
1202         return seq_open(file, &vmstat_op);
1203 }
1204
1205 static const struct file_operations proc_vmstat_file_operations = {
1206         .open           = vmstat_open,
1207         .read           = seq_read,
1208         .llseek         = seq_lseek,
1209         .release        = seq_release,
1210 };
1211 #endif /* CONFIG_PROC_FS */
1212
1213 #ifdef CONFIG_SMP
1214 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1215 int sysctl_stat_interval __read_mostly = HZ;
1216
1217 static void vmstat_update(struct work_struct *w)
1218 {
1219         refresh_cpu_vm_stats();
1220         schedule_delayed_work(&__get_cpu_var(vmstat_work),
1221                 round_jiffies_relative(sysctl_stat_interval));
1222 }
1223
1224 static void start_cpu_timer(int cpu)
1225 {
1226         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1227
1228         INIT_DEFERRABLE_WORK(work, vmstat_update);
1229         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1230 }
1231
1232 /*
1233  * Use the cpu notifier to insure that the thresholds are recalculated
1234  * when necessary.
1235  */
1236 static int vmstat_cpuup_callback(struct notifier_block *nfb,
1237                 unsigned long action,
1238                 void *hcpu)
1239 {
1240         long cpu = (long)hcpu;
1241
1242         switch (action) {
1243         case CPU_ONLINE:
1244         case CPU_ONLINE_FROZEN:
1245                 refresh_zone_stat_thresholds();
1246                 start_cpu_timer(cpu);
1247                 node_set_state(cpu_to_node(cpu), N_CPU);
1248                 break;
1249         case CPU_DOWN_PREPARE:
1250         case CPU_DOWN_PREPARE_FROZEN:
1251                 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1252                 per_cpu(vmstat_work, cpu).work.func = NULL;
1253                 break;
1254         case CPU_DOWN_FAILED:
1255         case CPU_DOWN_FAILED_FROZEN:
1256                 start_cpu_timer(cpu);
1257                 break;
1258         case CPU_DEAD:
1259         case CPU_DEAD_FROZEN:
1260                 refresh_zone_stat_thresholds();
1261                 break;
1262         default:
1263                 break;
1264         }
1265         return NOTIFY_OK;
1266 }
1267
1268 static struct notifier_block vmstat_notifier =
1269         { &vmstat_cpuup_callback, NULL, 0 };
1270 #endif
1271
1272 static int __init setup_vmstat(void)
1273 {
1274 #ifdef CONFIG_SMP
1275         int cpu;
1276
1277         register_cpu_notifier(&vmstat_notifier);
1278
1279         for_each_online_cpu(cpu)
1280                 start_cpu_timer(cpu);
1281 #endif
1282 #ifdef CONFIG_PROC_FS
1283         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1284         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1285         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1286         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1287 #endif
1288         return 0;
1289 }
1290 module_init(setup_vmstat)
1291
1292 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1293 #include <linux/debugfs.h>
1294
1295
1296 /*
1297  * Return an index indicating how much of the available free memory is
1298  * unusable for an allocation of the requested size.
1299  */
1300 static int unusable_free_index(unsigned int order,
1301                                 struct contig_page_info *info)
1302 {
1303         /* No free memory is interpreted as all free memory is unusable */
1304         if (info->free_pages == 0)
1305                 return 1000;
1306
1307         /*
1308          * Index should be a value between 0 and 1. Return a value to 3
1309          * decimal places.
1310          *
1311          * 0 => no fragmentation
1312          * 1 => high fragmentation
1313          */
1314         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1315
1316 }
1317
1318 static void unusable_show_print(struct seq_file *m,
1319                                         pg_data_t *pgdat, struct zone *zone)
1320 {
1321         unsigned int order;
1322         int index;
1323         struct contig_page_info info;
1324
1325         seq_printf(m, "Node %d, zone %8s ",
1326                                 pgdat->node_id,
1327                                 zone->name);
1328         for (order = 0; order < MAX_ORDER; ++order) {
1329                 fill_contig_page_info(zone, order, &info);
1330                 index = unusable_free_index(order, &info);
1331                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1332         }
1333
1334         seq_putc(m, '\n');
1335 }
1336
1337 /*
1338  * Display unusable free space index
1339  *
1340  * The unusable free space index measures how much of the available free
1341  * memory cannot be used to satisfy an allocation of a given size and is a
1342  * value between 0 and 1. The higher the value, the more of free memory is
1343  * unusable and by implication, the worse the external fragmentation is. This
1344  * can be expressed as a percentage by multiplying by 100.
1345  */
1346 static int unusable_show(struct seq_file *m, void *arg)
1347 {
1348         pg_data_t *pgdat = (pg_data_t *)arg;
1349
1350         /* check memoryless node */
1351         if (!node_state(pgdat->node_id, N_MEMORY))
1352                 return 0;
1353
1354         walk_zones_in_node(m, pgdat, unusable_show_print);
1355
1356         return 0;
1357 }
1358
1359 static const struct seq_operations unusable_op = {
1360         .start  = frag_start,
1361         .next   = frag_next,
1362         .stop   = frag_stop,
1363         .show   = unusable_show,
1364 };
1365
1366 static int unusable_open(struct inode *inode, struct file *file)
1367 {
1368         return seq_open(file, &unusable_op);
1369 }
1370
1371 static const struct file_operations unusable_file_ops = {
1372         .open           = unusable_open,
1373         .read           = seq_read,
1374         .llseek         = seq_lseek,
1375         .release        = seq_release,
1376 };
1377
1378 static void extfrag_show_print(struct seq_file *m,
1379                                         pg_data_t *pgdat, struct zone *zone)
1380 {
1381         unsigned int order;
1382         int index;
1383
1384         /* Alloc on stack as interrupts are disabled for zone walk */
1385         struct contig_page_info info;
1386
1387         seq_printf(m, "Node %d, zone %8s ",
1388                                 pgdat->node_id,
1389                                 zone->name);
1390         for (order = 0; order < MAX_ORDER; ++order) {
1391                 fill_contig_page_info(zone, order, &info);
1392                 index = __fragmentation_index(order, &info);
1393                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1394         }
1395
1396         seq_putc(m, '\n');
1397 }
1398
1399 /*
1400  * Display fragmentation index for orders that allocations would fail for
1401  */
1402 static int extfrag_show(struct seq_file *m, void *arg)
1403 {
1404         pg_data_t *pgdat = (pg_data_t *)arg;
1405
1406         walk_zones_in_node(m, pgdat, extfrag_show_print);
1407
1408         return 0;
1409 }
1410
1411 static const struct seq_operations extfrag_op = {
1412         .start  = frag_start,
1413         .next   = frag_next,
1414         .stop   = frag_stop,
1415         .show   = extfrag_show,
1416 };
1417
1418 static int extfrag_open(struct inode *inode, struct file *file)
1419 {
1420         return seq_open(file, &extfrag_op);
1421 }
1422
1423 static const struct file_operations extfrag_file_ops = {
1424         .open           = extfrag_open,
1425         .read           = seq_read,
1426         .llseek         = seq_lseek,
1427         .release        = seq_release,
1428 };
1429
1430 static int __init extfrag_debug_init(void)
1431 {
1432         struct dentry *extfrag_debug_root;
1433
1434         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1435         if (!extfrag_debug_root)
1436                 return -ENOMEM;
1437
1438         if (!debugfs_create_file("unusable_index", 0444,
1439                         extfrag_debug_root, NULL, &unusable_file_ops))
1440                 goto fail;
1441
1442         if (!debugfs_create_file("extfrag_index", 0444,
1443                         extfrag_debug_root, NULL, &extfrag_file_ops))
1444                 goto fail;
1445
1446         return 0;
1447 fail:
1448         debugfs_remove_recursive(extfrag_debug_root);
1449         return -ENOMEM;
1450 }
1451
1452 module_init(extfrag_debug_init);
1453 #endif