vmstat: Use this_cpu_inc_return for vm statistics
[linux-2.6.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
23 #ifdef CONFIG_VM_EVENT_COUNTERS
24 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
25 EXPORT_PER_CPU_SYMBOL(vm_event_states);
26
27 static void sum_vm_events(unsigned long *ret)
28 {
29         int cpu;
30         int i;
31
32         memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
33
34         for_each_online_cpu(cpu) {
35                 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
36
37                 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
38                         ret[i] += this->event[i];
39         }
40 }
41
42 /*
43  * Accumulate the vm event counters across all CPUs.
44  * The result is unavoidably approximate - it can change
45  * during and after execution of this function.
46 */
47 void all_vm_events(unsigned long *ret)
48 {
49         get_online_cpus();
50         sum_vm_events(ret);
51         put_online_cpus();
52 }
53 EXPORT_SYMBOL_GPL(all_vm_events);
54
55 #ifdef CONFIG_HOTPLUG
56 /*
57  * Fold the foreign cpu events into our own.
58  *
59  * This is adding to the events on one processor
60  * but keeps the global counts constant.
61  */
62 void vm_events_fold_cpu(int cpu)
63 {
64         struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
65         int i;
66
67         for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
68                 count_vm_events(i, fold_state->event[i]);
69                 fold_state->event[i] = 0;
70         }
71 }
72 #endif /* CONFIG_HOTPLUG */
73
74 #endif /* CONFIG_VM_EVENT_COUNTERS */
75
76 /*
77  * Manage combined zone based / global counters
78  *
79  * vm_stat contains the global counters
80  */
81 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
82 EXPORT_SYMBOL(vm_stat);
83
84 #ifdef CONFIG_SMP
85
86 static int calculate_threshold(struct zone *zone)
87 {
88         int threshold;
89         int mem;        /* memory in 128 MB units */
90
91         /*
92          * The threshold scales with the number of processors and the amount
93          * of memory per zone. More memory means that we can defer updates for
94          * longer, more processors could lead to more contention.
95          * fls() is used to have a cheap way of logarithmic scaling.
96          *
97          * Some sample thresholds:
98          *
99          * Threshold    Processors      (fls)   Zonesize        fls(mem+1)
100          * ------------------------------------------------------------------
101          * 8            1               1       0.9-1 GB        4
102          * 16           2               2       0.9-1 GB        4
103          * 20           2               2       1-2 GB          5
104          * 24           2               2       2-4 GB          6
105          * 28           2               2       4-8 GB          7
106          * 32           2               2       8-16 GB         8
107          * 4            2               2       <128M           1
108          * 30           4               3       2-4 GB          5
109          * 48           4               3       8-16 GB         8
110          * 32           8               4       1-2 GB          4
111          * 32           8               4       0.9-1GB         4
112          * 10           16              5       <128M           1
113          * 40           16              5       900M            4
114          * 70           64              7       2-4 GB          5
115          * 84           64              7       4-8 GB          6
116          * 108          512             9       4-8 GB          6
117          * 125          1024            10      8-16 GB         8
118          * 125          1024            10      16-32 GB        9
119          */
120
121         mem = zone->present_pages >> (27 - PAGE_SHIFT);
122
123         threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
124
125         /*
126          * Maximum threshold is 125
127          */
128         threshold = min(125, threshold);
129
130         return threshold;
131 }
132
133 /*
134  * Refresh the thresholds for each zone.
135  */
136 static void refresh_zone_stat_thresholds(void)
137 {
138         struct zone *zone;
139         int cpu;
140         int threshold;
141
142         for_each_populated_zone(zone) {
143                 unsigned long max_drift, tolerate_drift;
144
145                 threshold = calculate_threshold(zone);
146
147                 for_each_online_cpu(cpu)
148                         per_cpu_ptr(zone->pageset, cpu)->stat_threshold
149                                                         = threshold;
150
151                 /*
152                  * Only set percpu_drift_mark if there is a danger that
153                  * NR_FREE_PAGES reports the low watermark is ok when in fact
154                  * the min watermark could be breached by an allocation
155                  */
156                 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
157                 max_drift = num_online_cpus() * threshold;
158                 if (max_drift > tolerate_drift)
159                         zone->percpu_drift_mark = high_wmark_pages(zone) +
160                                         max_drift;
161         }
162 }
163
164 /*
165  * For use when we know that interrupts are disabled.
166  */
167 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
168                                 int delta)
169 {
170         struct per_cpu_pageset __percpu *pcp = zone->pageset;
171         s8 __percpu *p = pcp->vm_stat_diff + item;
172         long x;
173         long t;
174
175         x = delta + __this_cpu_read(*p);
176
177         t = __this_cpu_read(pcp->stat_threshold);
178
179         if (unlikely(x > t || x < -t)) {
180                 zone_page_state_add(x, zone, item);
181                 x = 0;
182         }
183         __this_cpu_write(*p, x);
184 }
185 EXPORT_SYMBOL(__mod_zone_page_state);
186
187 /*
188  * For an unknown interrupt state
189  */
190 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
191                                         int delta)
192 {
193         unsigned long flags;
194
195         local_irq_save(flags);
196         __mod_zone_page_state(zone, item, delta);
197         local_irq_restore(flags);
198 }
199 EXPORT_SYMBOL(mod_zone_page_state);
200
201 /*
202  * Optimized increment and decrement functions.
203  *
204  * These are only for a single page and therefore can take a struct page *
205  * argument instead of struct zone *. This allows the inclusion of the code
206  * generated for page_zone(page) into the optimized functions.
207  *
208  * No overflow check is necessary and therefore the differential can be
209  * incremented or decremented in place which may allow the compilers to
210  * generate better code.
211  * The increment or decrement is known and therefore one boundary check can
212  * be omitted.
213  *
214  * NOTE: These functions are very performance sensitive. Change only
215  * with care.
216  *
217  * Some processors have inc/dec instructions that are atomic vs an interrupt.
218  * However, the code must first determine the differential location in a zone
219  * based on the processor number and then inc/dec the counter. There is no
220  * guarantee without disabling preemption that the processor will not change
221  * in between and therefore the atomicity vs. interrupt cannot be exploited
222  * in a useful way here.
223  */
224 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
225 {
226         struct per_cpu_pageset __percpu *pcp = zone->pageset;
227         s8 __percpu *p = pcp->vm_stat_diff + item;
228         s8 v, t;
229
230         v = __this_cpu_inc_return(*p);
231         t = __this_cpu_read(pcp->stat_threshold);
232         if (unlikely(v > t)) {
233                 s8 overstep = t >> 1;
234
235                 zone_page_state_add(v + overstep, zone, item);
236                 __this_cpu_write(*p, -overstep);
237         }
238 }
239
240 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
241 {
242         __inc_zone_state(page_zone(page), item);
243 }
244 EXPORT_SYMBOL(__inc_zone_page_state);
245
246 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
247 {
248         struct per_cpu_pageset __percpu *pcp = zone->pageset;
249         s8 __percpu *p = pcp->vm_stat_diff + item;
250         s8 v, t;
251
252         v = __this_cpu_dec_return(*p);
253         t = __this_cpu_read(pcp->stat_threshold);
254         if (unlikely(v < - t)) {
255                 s8 overstep = t >> 1;
256
257                 zone_page_state_add(v - overstep, zone, item);
258                 __this_cpu_write(*p, overstep);
259         }
260 }
261
262 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
263 {
264         __dec_zone_state(page_zone(page), item);
265 }
266 EXPORT_SYMBOL(__dec_zone_page_state);
267
268 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
269 {
270         unsigned long flags;
271
272         local_irq_save(flags);
273         __inc_zone_state(zone, item);
274         local_irq_restore(flags);
275 }
276
277 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
278 {
279         unsigned long flags;
280         struct zone *zone;
281
282         zone = page_zone(page);
283         local_irq_save(flags);
284         __inc_zone_state(zone, item);
285         local_irq_restore(flags);
286 }
287 EXPORT_SYMBOL(inc_zone_page_state);
288
289 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
290 {
291         unsigned long flags;
292
293         local_irq_save(flags);
294         __dec_zone_page_state(page, item);
295         local_irq_restore(flags);
296 }
297 EXPORT_SYMBOL(dec_zone_page_state);
298
299 /*
300  * Update the zone counters for one cpu.
301  *
302  * The cpu specified must be either the current cpu or a processor that
303  * is not online. If it is the current cpu then the execution thread must
304  * be pinned to the current cpu.
305  *
306  * Note that refresh_cpu_vm_stats strives to only access
307  * node local memory. The per cpu pagesets on remote zones are placed
308  * in the memory local to the processor using that pageset. So the
309  * loop over all zones will access a series of cachelines local to
310  * the processor.
311  *
312  * The call to zone_page_state_add updates the cachelines with the
313  * statistics in the remote zone struct as well as the global cachelines
314  * with the global counters. These could cause remote node cache line
315  * bouncing and will have to be only done when necessary.
316  */
317 void refresh_cpu_vm_stats(int cpu)
318 {
319         struct zone *zone;
320         int i;
321         int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
322
323         for_each_populated_zone(zone) {
324                 struct per_cpu_pageset *p;
325
326                 p = per_cpu_ptr(zone->pageset, cpu);
327
328                 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
329                         if (p->vm_stat_diff[i]) {
330                                 unsigned long flags;
331                                 int v;
332
333                                 local_irq_save(flags);
334                                 v = p->vm_stat_diff[i];
335                                 p->vm_stat_diff[i] = 0;
336                                 local_irq_restore(flags);
337                                 atomic_long_add(v, &zone->vm_stat[i]);
338                                 global_diff[i] += v;
339 #ifdef CONFIG_NUMA
340                                 /* 3 seconds idle till flush */
341                                 p->expire = 3;
342 #endif
343                         }
344                 cond_resched();
345 #ifdef CONFIG_NUMA
346                 /*
347                  * Deal with draining the remote pageset of this
348                  * processor
349                  *
350                  * Check if there are pages remaining in this pageset
351                  * if not then there is nothing to expire.
352                  */
353                 if (!p->expire || !p->pcp.count)
354                         continue;
355
356                 /*
357                  * We never drain zones local to this processor.
358                  */
359                 if (zone_to_nid(zone) == numa_node_id()) {
360                         p->expire = 0;
361                         continue;
362                 }
363
364                 p->expire--;
365                 if (p->expire)
366                         continue;
367
368                 if (p->pcp.count)
369                         drain_zone_pages(zone, &p->pcp);
370 #endif
371         }
372
373         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
374                 if (global_diff[i])
375                         atomic_long_add(global_diff[i], &vm_stat[i]);
376 }
377
378 #endif
379
380 #ifdef CONFIG_NUMA
381 /*
382  * zonelist = the list of zones passed to the allocator
383  * z        = the zone from which the allocation occurred.
384  *
385  * Must be called with interrupts disabled.
386  */
387 void zone_statistics(struct zone *preferred_zone, struct zone *z)
388 {
389         if (z->zone_pgdat == preferred_zone->zone_pgdat) {
390                 __inc_zone_state(z, NUMA_HIT);
391         } else {
392                 __inc_zone_state(z, NUMA_MISS);
393                 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
394         }
395         if (z->node == numa_node_id())
396                 __inc_zone_state(z, NUMA_LOCAL);
397         else
398                 __inc_zone_state(z, NUMA_OTHER);
399 }
400 #endif
401
402 #ifdef CONFIG_COMPACTION
403
404 struct contig_page_info {
405         unsigned long free_pages;
406         unsigned long free_blocks_total;
407         unsigned long free_blocks_suitable;
408 };
409
410 /*
411  * Calculate the number of free pages in a zone, how many contiguous
412  * pages are free and how many are large enough to satisfy an allocation of
413  * the target size. Note that this function makes no attempt to estimate
414  * how many suitable free blocks there *might* be if MOVABLE pages were
415  * migrated. Calculating that is possible, but expensive and can be
416  * figured out from userspace
417  */
418 static void fill_contig_page_info(struct zone *zone,
419                                 unsigned int suitable_order,
420                                 struct contig_page_info *info)
421 {
422         unsigned int order;
423
424         info->free_pages = 0;
425         info->free_blocks_total = 0;
426         info->free_blocks_suitable = 0;
427
428         for (order = 0; order < MAX_ORDER; order++) {
429                 unsigned long blocks;
430
431                 /* Count number of free blocks */
432                 blocks = zone->free_area[order].nr_free;
433                 info->free_blocks_total += blocks;
434
435                 /* Count free base pages */
436                 info->free_pages += blocks << order;
437
438                 /* Count the suitable free blocks */
439                 if (order >= suitable_order)
440                         info->free_blocks_suitable += blocks <<
441                                                 (order - suitable_order);
442         }
443 }
444
445 /*
446  * A fragmentation index only makes sense if an allocation of a requested
447  * size would fail. If that is true, the fragmentation index indicates
448  * whether external fragmentation or a lack of memory was the problem.
449  * The value can be used to determine if page reclaim or compaction
450  * should be used
451  */
452 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
453 {
454         unsigned long requested = 1UL << order;
455
456         if (!info->free_blocks_total)
457                 return 0;
458
459         /* Fragmentation index only makes sense when a request would fail */
460         if (info->free_blocks_suitable)
461                 return -1000;
462
463         /*
464          * Index is between 0 and 1 so return within 3 decimal places
465          *
466          * 0 => allocation would fail due to lack of memory
467          * 1 => allocation would fail due to fragmentation
468          */
469         return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
470 }
471
472 /* Same as __fragmentation index but allocs contig_page_info on stack */
473 int fragmentation_index(struct zone *zone, unsigned int order)
474 {
475         struct contig_page_info info;
476
477         fill_contig_page_info(zone, order, &info);
478         return __fragmentation_index(order, &info);
479 }
480 #endif
481
482 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
483 #include <linux/proc_fs.h>
484 #include <linux/seq_file.h>
485
486 static char * const migratetype_names[MIGRATE_TYPES] = {
487         "Unmovable",
488         "Reclaimable",
489         "Movable",
490         "Reserve",
491         "Isolate",
492 };
493
494 static void *frag_start(struct seq_file *m, loff_t *pos)
495 {
496         pg_data_t *pgdat;
497         loff_t node = *pos;
498         for (pgdat = first_online_pgdat();
499              pgdat && node;
500              pgdat = next_online_pgdat(pgdat))
501                 --node;
502
503         return pgdat;
504 }
505
506 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
507 {
508         pg_data_t *pgdat = (pg_data_t *)arg;
509
510         (*pos)++;
511         return next_online_pgdat(pgdat);
512 }
513
514 static void frag_stop(struct seq_file *m, void *arg)
515 {
516 }
517
518 /* Walk all the zones in a node and print using a callback */
519 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
520                 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
521 {
522         struct zone *zone;
523         struct zone *node_zones = pgdat->node_zones;
524         unsigned long flags;
525
526         for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
527                 if (!populated_zone(zone))
528                         continue;
529
530                 spin_lock_irqsave(&zone->lock, flags);
531                 print(m, pgdat, zone);
532                 spin_unlock_irqrestore(&zone->lock, flags);
533         }
534 }
535 #endif
536
537 #ifdef CONFIG_PROC_FS
538 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
539                                                 struct zone *zone)
540 {
541         int order;
542
543         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
544         for (order = 0; order < MAX_ORDER; ++order)
545                 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
546         seq_putc(m, '\n');
547 }
548
549 /*
550  * This walks the free areas for each zone.
551  */
552 static int frag_show(struct seq_file *m, void *arg)
553 {
554         pg_data_t *pgdat = (pg_data_t *)arg;
555         walk_zones_in_node(m, pgdat, frag_show_print);
556         return 0;
557 }
558
559 static void pagetypeinfo_showfree_print(struct seq_file *m,
560                                         pg_data_t *pgdat, struct zone *zone)
561 {
562         int order, mtype;
563
564         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
565                 seq_printf(m, "Node %4d, zone %8s, type %12s ",
566                                         pgdat->node_id,
567                                         zone->name,
568                                         migratetype_names[mtype]);
569                 for (order = 0; order < MAX_ORDER; ++order) {
570                         unsigned long freecount = 0;
571                         struct free_area *area;
572                         struct list_head *curr;
573
574                         area = &(zone->free_area[order]);
575
576                         list_for_each(curr, &area->free_list[mtype])
577                                 freecount++;
578                         seq_printf(m, "%6lu ", freecount);
579                 }
580                 seq_putc(m, '\n');
581         }
582 }
583
584 /* Print out the free pages at each order for each migatetype */
585 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
586 {
587         int order;
588         pg_data_t *pgdat = (pg_data_t *)arg;
589
590         /* Print header */
591         seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
592         for (order = 0; order < MAX_ORDER; ++order)
593                 seq_printf(m, "%6d ", order);
594         seq_putc(m, '\n');
595
596         walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
597
598         return 0;
599 }
600
601 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
602                                         pg_data_t *pgdat, struct zone *zone)
603 {
604         int mtype;
605         unsigned long pfn;
606         unsigned long start_pfn = zone->zone_start_pfn;
607         unsigned long end_pfn = start_pfn + zone->spanned_pages;
608         unsigned long count[MIGRATE_TYPES] = { 0, };
609
610         for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
611                 struct page *page;
612
613                 if (!pfn_valid(pfn))
614                         continue;
615
616                 page = pfn_to_page(pfn);
617
618                 /* Watch for unexpected holes punched in the memmap */
619                 if (!memmap_valid_within(pfn, page, zone))
620                         continue;
621
622                 mtype = get_pageblock_migratetype(page);
623
624                 if (mtype < MIGRATE_TYPES)
625                         count[mtype]++;
626         }
627
628         /* Print counts */
629         seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
630         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
631                 seq_printf(m, "%12lu ", count[mtype]);
632         seq_putc(m, '\n');
633 }
634
635 /* Print out the free pages at each order for each migratetype */
636 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
637 {
638         int mtype;
639         pg_data_t *pgdat = (pg_data_t *)arg;
640
641         seq_printf(m, "\n%-23s", "Number of blocks type ");
642         for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
643                 seq_printf(m, "%12s ", migratetype_names[mtype]);
644         seq_putc(m, '\n');
645         walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
646
647         return 0;
648 }
649
650 /*
651  * This prints out statistics in relation to grouping pages by mobility.
652  * It is expensive to collect so do not constantly read the file.
653  */
654 static int pagetypeinfo_show(struct seq_file *m, void *arg)
655 {
656         pg_data_t *pgdat = (pg_data_t *)arg;
657
658         /* check memoryless node */
659         if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
660                 return 0;
661
662         seq_printf(m, "Page block order: %d\n", pageblock_order);
663         seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
664         seq_putc(m, '\n');
665         pagetypeinfo_showfree(m, pgdat);
666         pagetypeinfo_showblockcount(m, pgdat);
667
668         return 0;
669 }
670
671 static const struct seq_operations fragmentation_op = {
672         .start  = frag_start,
673         .next   = frag_next,
674         .stop   = frag_stop,
675         .show   = frag_show,
676 };
677
678 static int fragmentation_open(struct inode *inode, struct file *file)
679 {
680         return seq_open(file, &fragmentation_op);
681 }
682
683 static const struct file_operations fragmentation_file_operations = {
684         .open           = fragmentation_open,
685         .read           = seq_read,
686         .llseek         = seq_lseek,
687         .release        = seq_release,
688 };
689
690 static const struct seq_operations pagetypeinfo_op = {
691         .start  = frag_start,
692         .next   = frag_next,
693         .stop   = frag_stop,
694         .show   = pagetypeinfo_show,
695 };
696
697 static int pagetypeinfo_open(struct inode *inode, struct file *file)
698 {
699         return seq_open(file, &pagetypeinfo_op);
700 }
701
702 static const struct file_operations pagetypeinfo_file_ops = {
703         .open           = pagetypeinfo_open,
704         .read           = seq_read,
705         .llseek         = seq_lseek,
706         .release        = seq_release,
707 };
708
709 #ifdef CONFIG_ZONE_DMA
710 #define TEXT_FOR_DMA(xx) xx "_dma",
711 #else
712 #define TEXT_FOR_DMA(xx)
713 #endif
714
715 #ifdef CONFIG_ZONE_DMA32
716 #define TEXT_FOR_DMA32(xx) xx "_dma32",
717 #else
718 #define TEXT_FOR_DMA32(xx)
719 #endif
720
721 #ifdef CONFIG_HIGHMEM
722 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
723 #else
724 #define TEXT_FOR_HIGHMEM(xx)
725 #endif
726
727 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
728                                         TEXT_FOR_HIGHMEM(xx) xx "_movable",
729
730 static const char * const vmstat_text[] = {
731         /* Zoned VM counters */
732         "nr_free_pages",
733         "nr_inactive_anon",
734         "nr_active_anon",
735         "nr_inactive_file",
736         "nr_active_file",
737         "nr_unevictable",
738         "nr_mlock",
739         "nr_anon_pages",
740         "nr_mapped",
741         "nr_file_pages",
742         "nr_dirty",
743         "nr_writeback",
744         "nr_slab_reclaimable",
745         "nr_slab_unreclaimable",
746         "nr_page_table_pages",
747         "nr_kernel_stack",
748         "nr_unstable",
749         "nr_bounce",
750         "nr_vmscan_write",
751         "nr_writeback_temp",
752         "nr_isolated_anon",
753         "nr_isolated_file",
754         "nr_shmem",
755         "nr_dirtied",
756         "nr_written",
757
758 #ifdef CONFIG_NUMA
759         "numa_hit",
760         "numa_miss",
761         "numa_foreign",
762         "numa_interleave",
763         "numa_local",
764         "numa_other",
765 #endif
766         "nr_dirty_threshold",
767         "nr_dirty_background_threshold",
768
769 #ifdef CONFIG_VM_EVENT_COUNTERS
770         "pgpgin",
771         "pgpgout",
772         "pswpin",
773         "pswpout",
774
775         TEXTS_FOR_ZONES("pgalloc")
776
777         "pgfree",
778         "pgactivate",
779         "pgdeactivate",
780
781         "pgfault",
782         "pgmajfault",
783
784         TEXTS_FOR_ZONES("pgrefill")
785         TEXTS_FOR_ZONES("pgsteal")
786         TEXTS_FOR_ZONES("pgscan_kswapd")
787         TEXTS_FOR_ZONES("pgscan_direct")
788
789 #ifdef CONFIG_NUMA
790         "zone_reclaim_failed",
791 #endif
792         "pginodesteal",
793         "slabs_scanned",
794         "kswapd_steal",
795         "kswapd_inodesteal",
796         "kswapd_low_wmark_hit_quickly",
797         "kswapd_high_wmark_hit_quickly",
798         "kswapd_skip_congestion_wait",
799         "pageoutrun",
800         "allocstall",
801
802         "pgrotated",
803
804 #ifdef CONFIG_COMPACTION
805         "compact_blocks_moved",
806         "compact_pages_moved",
807         "compact_pagemigrate_failed",
808         "compact_stall",
809         "compact_fail",
810         "compact_success",
811 #endif
812
813 #ifdef CONFIG_HUGETLB_PAGE
814         "htlb_buddy_alloc_success",
815         "htlb_buddy_alloc_fail",
816 #endif
817         "unevictable_pgs_culled",
818         "unevictable_pgs_scanned",
819         "unevictable_pgs_rescued",
820         "unevictable_pgs_mlocked",
821         "unevictable_pgs_munlocked",
822         "unevictable_pgs_cleared",
823         "unevictable_pgs_stranded",
824         "unevictable_pgs_mlockfreed",
825 #endif
826 };
827
828 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
829                                                         struct zone *zone)
830 {
831         int i;
832         seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
833         seq_printf(m,
834                    "\n  pages free     %lu"
835                    "\n        min      %lu"
836                    "\n        low      %lu"
837                    "\n        high     %lu"
838                    "\n        scanned  %lu"
839                    "\n        spanned  %lu"
840                    "\n        present  %lu",
841                    zone_nr_free_pages(zone),
842                    min_wmark_pages(zone),
843                    low_wmark_pages(zone),
844                    high_wmark_pages(zone),
845                    zone->pages_scanned,
846                    zone->spanned_pages,
847                    zone->present_pages);
848
849         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
850                 seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
851                                 zone_page_state(zone, i));
852
853         seq_printf(m,
854                    "\n        protection: (%lu",
855                    zone->lowmem_reserve[0]);
856         for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
857                 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
858         seq_printf(m,
859                    ")"
860                    "\n  pagesets");
861         for_each_online_cpu(i) {
862                 struct per_cpu_pageset *pageset;
863
864                 pageset = per_cpu_ptr(zone->pageset, i);
865                 seq_printf(m,
866                            "\n    cpu: %i"
867                            "\n              count: %i"
868                            "\n              high:  %i"
869                            "\n              batch: %i",
870                            i,
871                            pageset->pcp.count,
872                            pageset->pcp.high,
873                            pageset->pcp.batch);
874 #ifdef CONFIG_SMP
875                 seq_printf(m, "\n  vm stats threshold: %d",
876                                 pageset->stat_threshold);
877 #endif
878         }
879         seq_printf(m,
880                    "\n  all_unreclaimable: %u"
881                    "\n  start_pfn:         %lu"
882                    "\n  inactive_ratio:    %u",
883                    zone->all_unreclaimable,
884                    zone->zone_start_pfn,
885                    zone->inactive_ratio);
886         seq_putc(m, '\n');
887 }
888
889 /*
890  * Output information about zones in @pgdat.
891  */
892 static int zoneinfo_show(struct seq_file *m, void *arg)
893 {
894         pg_data_t *pgdat = (pg_data_t *)arg;
895         walk_zones_in_node(m, pgdat, zoneinfo_show_print);
896         return 0;
897 }
898
899 static const struct seq_operations zoneinfo_op = {
900         .start  = frag_start, /* iterate over all zones. The same as in
901                                * fragmentation. */
902         .next   = frag_next,
903         .stop   = frag_stop,
904         .show   = zoneinfo_show,
905 };
906
907 static int zoneinfo_open(struct inode *inode, struct file *file)
908 {
909         return seq_open(file, &zoneinfo_op);
910 }
911
912 static const struct file_operations proc_zoneinfo_file_operations = {
913         .open           = zoneinfo_open,
914         .read           = seq_read,
915         .llseek         = seq_lseek,
916         .release        = seq_release,
917 };
918
919 enum writeback_stat_item {
920         NR_DIRTY_THRESHOLD,
921         NR_DIRTY_BG_THRESHOLD,
922         NR_VM_WRITEBACK_STAT_ITEMS,
923 };
924
925 static void *vmstat_start(struct seq_file *m, loff_t *pos)
926 {
927         unsigned long *v;
928         int i, stat_items_size;
929
930         if (*pos >= ARRAY_SIZE(vmstat_text))
931                 return NULL;
932         stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
933                           NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
934
935 #ifdef CONFIG_VM_EVENT_COUNTERS
936         stat_items_size += sizeof(struct vm_event_state);
937 #endif
938
939         v = kmalloc(stat_items_size, GFP_KERNEL);
940         m->private = v;
941         if (!v)
942                 return ERR_PTR(-ENOMEM);
943         for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
944                 v[i] = global_page_state(i);
945         v += NR_VM_ZONE_STAT_ITEMS;
946
947         global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
948                             v + NR_DIRTY_THRESHOLD);
949         v += NR_VM_WRITEBACK_STAT_ITEMS;
950
951 #ifdef CONFIG_VM_EVENT_COUNTERS
952         all_vm_events(v);
953         v[PGPGIN] /= 2;         /* sectors -> kbytes */
954         v[PGPGOUT] /= 2;
955 #endif
956         return (unsigned long *)m->private + *pos;
957 }
958
959 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
960 {
961         (*pos)++;
962         if (*pos >= ARRAY_SIZE(vmstat_text))
963                 return NULL;
964         return (unsigned long *)m->private + *pos;
965 }
966
967 static int vmstat_show(struct seq_file *m, void *arg)
968 {
969         unsigned long *l = arg;
970         unsigned long off = l - (unsigned long *)m->private;
971
972         seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
973         return 0;
974 }
975
976 static void vmstat_stop(struct seq_file *m, void *arg)
977 {
978         kfree(m->private);
979         m->private = NULL;
980 }
981
982 static const struct seq_operations vmstat_op = {
983         .start  = vmstat_start,
984         .next   = vmstat_next,
985         .stop   = vmstat_stop,
986         .show   = vmstat_show,
987 };
988
989 static int vmstat_open(struct inode *inode, struct file *file)
990 {
991         return seq_open(file, &vmstat_op);
992 }
993
994 static const struct file_operations proc_vmstat_file_operations = {
995         .open           = vmstat_open,
996         .read           = seq_read,
997         .llseek         = seq_lseek,
998         .release        = seq_release,
999 };
1000 #endif /* CONFIG_PROC_FS */
1001
1002 #ifdef CONFIG_SMP
1003 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1004 int sysctl_stat_interval __read_mostly = HZ;
1005
1006 static void vmstat_update(struct work_struct *w)
1007 {
1008         refresh_cpu_vm_stats(smp_processor_id());
1009         schedule_delayed_work(&__get_cpu_var(vmstat_work),
1010                 round_jiffies_relative(sysctl_stat_interval));
1011 }
1012
1013 static void __cpuinit start_cpu_timer(int cpu)
1014 {
1015         struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1016
1017         INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1018         schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1019 }
1020
1021 /*
1022  * Use the cpu notifier to insure that the thresholds are recalculated
1023  * when necessary.
1024  */
1025 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1026                 unsigned long action,
1027                 void *hcpu)
1028 {
1029         long cpu = (long)hcpu;
1030
1031         switch (action) {
1032         case CPU_ONLINE:
1033         case CPU_ONLINE_FROZEN:
1034                 refresh_zone_stat_thresholds();
1035                 start_cpu_timer(cpu);
1036                 node_set_state(cpu_to_node(cpu), N_CPU);
1037                 break;
1038         case CPU_DOWN_PREPARE:
1039         case CPU_DOWN_PREPARE_FROZEN:
1040                 cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
1041                 per_cpu(vmstat_work, cpu).work.func = NULL;
1042                 break;
1043         case CPU_DOWN_FAILED:
1044         case CPU_DOWN_FAILED_FROZEN:
1045                 start_cpu_timer(cpu);
1046                 break;
1047         case CPU_DEAD:
1048         case CPU_DEAD_FROZEN:
1049                 refresh_zone_stat_thresholds();
1050                 break;
1051         default:
1052                 break;
1053         }
1054         return NOTIFY_OK;
1055 }
1056
1057 static struct notifier_block __cpuinitdata vmstat_notifier =
1058         { &vmstat_cpuup_callback, NULL, 0 };
1059 #endif
1060
1061 static int __init setup_vmstat(void)
1062 {
1063 #ifdef CONFIG_SMP
1064         int cpu;
1065
1066         refresh_zone_stat_thresholds();
1067         register_cpu_notifier(&vmstat_notifier);
1068
1069         for_each_online_cpu(cpu)
1070                 start_cpu_timer(cpu);
1071 #endif
1072 #ifdef CONFIG_PROC_FS
1073         proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1074         proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1075         proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1076         proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1077 #endif
1078         return 0;
1079 }
1080 module_init(setup_vmstat)
1081
1082 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1083 #include <linux/debugfs.h>
1084
1085 static struct dentry *extfrag_debug_root;
1086
1087 /*
1088  * Return an index indicating how much of the available free memory is
1089  * unusable for an allocation of the requested size.
1090  */
1091 static int unusable_free_index(unsigned int order,
1092                                 struct contig_page_info *info)
1093 {
1094         /* No free memory is interpreted as all free memory is unusable */
1095         if (info->free_pages == 0)
1096                 return 1000;
1097
1098         /*
1099          * Index should be a value between 0 and 1. Return a value to 3
1100          * decimal places.
1101          *
1102          * 0 => no fragmentation
1103          * 1 => high fragmentation
1104          */
1105         return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1106
1107 }
1108
1109 static void unusable_show_print(struct seq_file *m,
1110                                         pg_data_t *pgdat, struct zone *zone)
1111 {
1112         unsigned int order;
1113         int index;
1114         struct contig_page_info info;
1115
1116         seq_printf(m, "Node %d, zone %8s ",
1117                                 pgdat->node_id,
1118                                 zone->name);
1119         for (order = 0; order < MAX_ORDER; ++order) {
1120                 fill_contig_page_info(zone, order, &info);
1121                 index = unusable_free_index(order, &info);
1122                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1123         }
1124
1125         seq_putc(m, '\n');
1126 }
1127
1128 /*
1129  * Display unusable free space index
1130  *
1131  * The unusable free space index measures how much of the available free
1132  * memory cannot be used to satisfy an allocation of a given size and is a
1133  * value between 0 and 1. The higher the value, the more of free memory is
1134  * unusable and by implication, the worse the external fragmentation is. This
1135  * can be expressed as a percentage by multiplying by 100.
1136  */
1137 static int unusable_show(struct seq_file *m, void *arg)
1138 {
1139         pg_data_t *pgdat = (pg_data_t *)arg;
1140
1141         /* check memoryless node */
1142         if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1143                 return 0;
1144
1145         walk_zones_in_node(m, pgdat, unusable_show_print);
1146
1147         return 0;
1148 }
1149
1150 static const struct seq_operations unusable_op = {
1151         .start  = frag_start,
1152         .next   = frag_next,
1153         .stop   = frag_stop,
1154         .show   = unusable_show,
1155 };
1156
1157 static int unusable_open(struct inode *inode, struct file *file)
1158 {
1159         return seq_open(file, &unusable_op);
1160 }
1161
1162 static const struct file_operations unusable_file_ops = {
1163         .open           = unusable_open,
1164         .read           = seq_read,
1165         .llseek         = seq_lseek,
1166         .release        = seq_release,
1167 };
1168
1169 static void extfrag_show_print(struct seq_file *m,
1170                                         pg_data_t *pgdat, struct zone *zone)
1171 {
1172         unsigned int order;
1173         int index;
1174
1175         /* Alloc on stack as interrupts are disabled for zone walk */
1176         struct contig_page_info info;
1177
1178         seq_printf(m, "Node %d, zone %8s ",
1179                                 pgdat->node_id,
1180                                 zone->name);
1181         for (order = 0; order < MAX_ORDER; ++order) {
1182                 fill_contig_page_info(zone, order, &info);
1183                 index = __fragmentation_index(order, &info);
1184                 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1185         }
1186
1187         seq_putc(m, '\n');
1188 }
1189
1190 /*
1191  * Display fragmentation index for orders that allocations would fail for
1192  */
1193 static int extfrag_show(struct seq_file *m, void *arg)
1194 {
1195         pg_data_t *pgdat = (pg_data_t *)arg;
1196
1197         walk_zones_in_node(m, pgdat, extfrag_show_print);
1198
1199         return 0;
1200 }
1201
1202 static const struct seq_operations extfrag_op = {
1203         .start  = frag_start,
1204         .next   = frag_next,
1205         .stop   = frag_stop,
1206         .show   = extfrag_show,
1207 };
1208
1209 static int extfrag_open(struct inode *inode, struct file *file)
1210 {
1211         return seq_open(file, &extfrag_op);
1212 }
1213
1214 static const struct file_operations extfrag_file_ops = {
1215         .open           = extfrag_open,
1216         .read           = seq_read,
1217         .llseek         = seq_lseek,
1218         .release        = seq_release,
1219 };
1220
1221 static int __init extfrag_debug_init(void)
1222 {
1223         extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1224         if (!extfrag_debug_root)
1225                 return -ENOMEM;
1226
1227         if (!debugfs_create_file("unusable_index", 0444,
1228                         extfrag_debug_root, NULL, &unusable_file_ops))
1229                 return -ENOMEM;
1230
1231         if (!debugfs_create_file("extfrag_index", 0444,
1232                         extfrag_debug_root, NULL, &extfrag_file_ops))
1233                 return -ENOMEM;
1234
1235         return 0;
1236 }
1237
1238 module_init(extfrag_debug_init);
1239 #endif