Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / vmstat.c
blob897ea9e88238d1a9ffd99c4f35124988bbc85ef0
1 /*
2 * linux/mm/vmstat.c
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
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>
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);
27 static void sum_vm_events(unsigned long *ret)
29 int cpu;
30 int i;
32 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
34 for_each_online_cpu(cpu) {
35 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
37 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
38 ret[i] += this->event[i];
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.
47 void all_vm_events(unsigned long *ret)
49 get_online_cpus();
50 sum_vm_events(ret);
51 put_online_cpus();
53 EXPORT_SYMBOL_GPL(all_vm_events);
55 #ifdef CONFIG_HOTPLUG
57 * Fold the foreign cpu events into our own.
59 * This is adding to the events on one processor
60 * but keeps the global counts constant.
62 void vm_events_fold_cpu(int cpu)
64 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
65 int i;
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;
72 #endif /* CONFIG_HOTPLUG */
74 #endif /* CONFIG_VM_EVENT_COUNTERS */
77 * Manage combined zone based / global counters
79 * vm_stat contains the global counters
81 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
82 EXPORT_SYMBOL(vm_stat);
84 #ifdef CONFIG_SMP
86 int calculate_pressure_threshold(struct zone *zone)
88 int threshold;
89 int watermark_distance;
92 * As vmstats are not up to date, there is drift between the estimated
93 * and real values. For high thresholds and a high number of CPUs, it
94 * is possible for the min watermark to be breached while the estimated
95 * value looks fine. The pressure threshold is a reduced value such
96 * that even the maximum amount of drift will not accidentally breach
97 * the min watermark
99 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
100 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
103 * Maximum threshold is 125
105 threshold = min(125, threshold);
107 return threshold;
110 int calculate_normal_threshold(struct zone *zone)
112 int threshold;
113 int mem; /* memory in 128 MB units */
116 * The threshold scales with the number of processors and the amount
117 * of memory per zone. More memory means that we can defer updates for
118 * longer, more processors could lead to more contention.
119 * fls() is used to have a cheap way of logarithmic scaling.
121 * Some sample thresholds:
123 * Threshold Processors (fls) Zonesize fls(mem+1)
124 * ------------------------------------------------------------------
125 * 8 1 1 0.9-1 GB 4
126 * 16 2 2 0.9-1 GB 4
127 * 20 2 2 1-2 GB 5
128 * 24 2 2 2-4 GB 6
129 * 28 2 2 4-8 GB 7
130 * 32 2 2 8-16 GB 8
131 * 4 2 2 <128M 1
132 * 30 4 3 2-4 GB 5
133 * 48 4 3 8-16 GB 8
134 * 32 8 4 1-2 GB 4
135 * 32 8 4 0.9-1GB 4
136 * 10 16 5 <128M 1
137 * 40 16 5 900M 4
138 * 70 64 7 2-4 GB 5
139 * 84 64 7 4-8 GB 6
140 * 108 512 9 4-8 GB 6
141 * 125 1024 10 8-16 GB 8
142 * 125 1024 10 16-32 GB 9
145 mem = zone->present_pages >> (27 - PAGE_SHIFT);
147 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
150 * Maximum threshold is 125
152 threshold = min(125, threshold);
154 return threshold;
158 * Refresh the thresholds for each zone.
160 static void refresh_zone_stat_thresholds(void)
162 struct zone *zone;
163 int cpu;
164 int threshold;
166 for_each_populated_zone(zone) {
167 unsigned long max_drift, tolerate_drift;
169 threshold = calculate_normal_threshold(zone);
171 for_each_online_cpu(cpu)
172 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
173 = threshold;
176 * Only set percpu_drift_mark if there is a danger that
177 * NR_FREE_PAGES reports the low watermark is ok when in fact
178 * the min watermark could be breached by an allocation
180 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
181 max_drift = num_online_cpus() * threshold;
182 if (max_drift > tolerate_drift)
183 zone->percpu_drift_mark = high_wmark_pages(zone) +
184 max_drift;
188 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
189 int (*calculate_pressure)(struct zone *))
191 struct zone *zone;
192 int cpu;
193 int threshold;
194 int i;
196 for (i = 0; i < pgdat->nr_zones; i++) {
197 zone = &pgdat->node_zones[i];
198 if (!zone->percpu_drift_mark)
199 continue;
201 threshold = (*calculate_pressure)(zone);
202 for_each_possible_cpu(cpu)
203 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
204 = threshold;
209 * For use when we know that interrupts are disabled.
211 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
212 int delta)
214 struct per_cpu_pageset __percpu *pcp = zone->pageset;
215 s8 __percpu *p = pcp->vm_stat_diff + item;
216 long x;
217 long t;
219 x = delta + __this_cpu_read(*p);
221 t = __this_cpu_read(pcp->stat_threshold);
223 if (unlikely(x > t || x < -t)) {
224 zone_page_state_add(x, zone, item);
225 x = 0;
227 __this_cpu_write(*p, x);
229 EXPORT_SYMBOL(__mod_zone_page_state);
232 * Optimized increment and decrement functions.
234 * These are only for a single page and therefore can take a struct page *
235 * argument instead of struct zone *. This allows the inclusion of the code
236 * generated for page_zone(page) into the optimized functions.
238 * No overflow check is necessary and therefore the differential can be
239 * incremented or decremented in place which may allow the compilers to
240 * generate better code.
241 * The increment or decrement is known and therefore one boundary check can
242 * be omitted.
244 * NOTE: These functions are very performance sensitive. Change only
245 * with care.
247 * Some processors have inc/dec instructions that are atomic vs an interrupt.
248 * However, the code must first determine the differential location in a zone
249 * based on the processor number and then inc/dec the counter. There is no
250 * guarantee without disabling preemption that the processor will not change
251 * in between and therefore the atomicity vs. interrupt cannot be exploited
252 * in a useful way here.
254 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
256 struct per_cpu_pageset __percpu *pcp = zone->pageset;
257 s8 __percpu *p = pcp->vm_stat_diff + item;
258 s8 v, t;
260 v = __this_cpu_inc_return(*p);
261 t = __this_cpu_read(pcp->stat_threshold);
262 if (unlikely(v > t)) {
263 s8 overstep = t >> 1;
265 zone_page_state_add(v + overstep, zone, item);
266 __this_cpu_write(*p, -overstep);
270 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
272 __inc_zone_state(page_zone(page), item);
274 EXPORT_SYMBOL(__inc_zone_page_state);
276 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
278 struct per_cpu_pageset __percpu *pcp = zone->pageset;
279 s8 __percpu *p = pcp->vm_stat_diff + item;
280 s8 v, t;
282 v = __this_cpu_dec_return(*p);
283 t = __this_cpu_read(pcp->stat_threshold);
284 if (unlikely(v < - t)) {
285 s8 overstep = t >> 1;
287 zone_page_state_add(v - overstep, zone, item);
288 __this_cpu_write(*p, overstep);
292 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
294 __dec_zone_state(page_zone(page), item);
296 EXPORT_SYMBOL(__dec_zone_page_state);
298 #ifdef CONFIG_CMPXCHG_LOCAL
300 * If we have cmpxchg_local support then we do not need to incur the overhead
301 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
303 * mod_state() modifies the zone counter state through atomic per cpu
304 * operations.
306 * Overstep mode specifies how overstep should handled:
307 * 0 No overstepping
308 * 1 Overstepping half of threshold
309 * -1 Overstepping minus half of threshold
311 static inline void mod_state(struct zone *zone,
312 enum zone_stat_item item, int delta, int overstep_mode)
314 struct per_cpu_pageset __percpu *pcp = zone->pageset;
315 s8 __percpu *p = pcp->vm_stat_diff + item;
316 long o, n, t, z;
318 do {
319 z = 0; /* overflow to zone counters */
322 * The fetching of the stat_threshold is racy. We may apply
323 * a counter threshold to the wrong the cpu if we get
324 * rescheduled while executing here. However, the next
325 * counter update will apply the threshold again and
326 * therefore bring the counter under the threshold again.
328 * Most of the time the thresholds are the same anyways
329 * for all cpus in a zone.
331 t = this_cpu_read(pcp->stat_threshold);
333 o = this_cpu_read(*p);
334 n = delta + o;
336 if (n > t || n < -t) {
337 int os = overstep_mode * (t >> 1) ;
339 /* Overflow must be added to zone counters */
340 z = n + os;
341 n = -os;
343 } while (this_cpu_cmpxchg(*p, o, n) != o);
345 if (z)
346 zone_page_state_add(z, zone, item);
349 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
350 int delta)
352 mod_state(zone, item, delta, 0);
354 EXPORT_SYMBOL(mod_zone_page_state);
356 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
358 mod_state(zone, item, 1, 1);
361 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
363 mod_state(page_zone(page), item, 1, 1);
365 EXPORT_SYMBOL(inc_zone_page_state);
367 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
369 mod_state(page_zone(page), item, -1, -1);
371 EXPORT_SYMBOL(dec_zone_page_state);
372 #else
374 * Use interrupt disable to serialize counter updates
376 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
377 int delta)
379 unsigned long flags;
381 local_irq_save(flags);
382 __mod_zone_page_state(zone, item, delta);
383 local_irq_restore(flags);
385 EXPORT_SYMBOL(mod_zone_page_state);
387 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
389 unsigned long flags;
391 local_irq_save(flags);
392 __inc_zone_state(zone, item);
393 local_irq_restore(flags);
396 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
398 unsigned long flags;
399 struct zone *zone;
401 zone = page_zone(page);
402 local_irq_save(flags);
403 __inc_zone_state(zone, item);
404 local_irq_restore(flags);
406 EXPORT_SYMBOL(inc_zone_page_state);
408 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
410 unsigned long flags;
412 local_irq_save(flags);
413 __dec_zone_page_state(page, item);
414 local_irq_restore(flags);
416 EXPORT_SYMBOL(dec_zone_page_state);
417 #endif
420 * Update the zone counters for one cpu.
422 * The cpu specified must be either the current cpu or a processor that
423 * is not online. If it is the current cpu then the execution thread must
424 * be pinned to the current cpu.
426 * Note that refresh_cpu_vm_stats strives to only access
427 * node local memory. The per cpu pagesets on remote zones are placed
428 * in the memory local to the processor using that pageset. So the
429 * loop over all zones will access a series of cachelines local to
430 * the processor.
432 * The call to zone_page_state_add updates the cachelines with the
433 * statistics in the remote zone struct as well as the global cachelines
434 * with the global counters. These could cause remote node cache line
435 * bouncing and will have to be only done when necessary.
437 void refresh_cpu_vm_stats(int cpu)
439 struct zone *zone;
440 int i;
441 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
443 for_each_populated_zone(zone) {
444 struct per_cpu_pageset *p;
446 p = per_cpu_ptr(zone->pageset, cpu);
448 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
449 if (p->vm_stat_diff[i]) {
450 unsigned long flags;
451 int v;
453 local_irq_save(flags);
454 v = p->vm_stat_diff[i];
455 p->vm_stat_diff[i] = 0;
456 local_irq_restore(flags);
457 atomic_long_add(v, &zone->vm_stat[i]);
458 global_diff[i] += v;
459 #ifdef CONFIG_NUMA
460 /* 3 seconds idle till flush */
461 p->expire = 3;
462 #endif
464 cond_resched();
465 #ifdef CONFIG_NUMA
467 * Deal with draining the remote pageset of this
468 * processor
470 * Check if there are pages remaining in this pageset
471 * if not then there is nothing to expire.
473 if (!p->expire || !p->pcp.count)
474 continue;
477 * We never drain zones local to this processor.
479 if (zone_to_nid(zone) == numa_node_id()) {
480 p->expire = 0;
481 continue;
484 p->expire--;
485 if (p->expire)
486 continue;
488 if (p->pcp.count)
489 drain_zone_pages(zone, &p->pcp);
490 #endif
493 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
494 if (global_diff[i])
495 atomic_long_add(global_diff[i], &vm_stat[i]);
498 #endif
500 #ifdef CONFIG_NUMA
502 * zonelist = the list of zones passed to the allocator
503 * z = the zone from which the allocation occurred.
505 * Must be called with interrupts disabled.
507 * When __GFP_OTHER_NODE is set assume the node of the preferred
508 * zone is the local node. This is useful for daemons who allocate
509 * memory on behalf of other processes.
511 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
513 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
514 __inc_zone_state(z, NUMA_HIT);
515 } else {
516 __inc_zone_state(z, NUMA_MISS);
517 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
519 if (z->node == ((flags & __GFP_OTHER_NODE) ?
520 preferred_zone->node : numa_node_id()))
521 __inc_zone_state(z, NUMA_LOCAL);
522 else
523 __inc_zone_state(z, NUMA_OTHER);
525 #endif
527 #ifdef CONFIG_COMPACTION
529 struct contig_page_info {
530 unsigned long free_pages;
531 unsigned long free_blocks_total;
532 unsigned long free_blocks_suitable;
536 * Calculate the number of free pages in a zone, how many contiguous
537 * pages are free and how many are large enough to satisfy an allocation of
538 * the target size. Note that this function makes no attempt to estimate
539 * how many suitable free blocks there *might* be if MOVABLE pages were
540 * migrated. Calculating that is possible, but expensive and can be
541 * figured out from userspace
543 static void fill_contig_page_info(struct zone *zone,
544 unsigned int suitable_order,
545 struct contig_page_info *info)
547 unsigned int order;
549 info->free_pages = 0;
550 info->free_blocks_total = 0;
551 info->free_blocks_suitable = 0;
553 for (order = 0; order < MAX_ORDER; order++) {
554 unsigned long blocks;
556 /* Count number of free blocks */
557 blocks = zone->free_area[order].nr_free;
558 info->free_blocks_total += blocks;
560 /* Count free base pages */
561 info->free_pages += blocks << order;
563 /* Count the suitable free blocks */
564 if (order >= suitable_order)
565 info->free_blocks_suitable += blocks <<
566 (order - suitable_order);
571 * A fragmentation index only makes sense if an allocation of a requested
572 * size would fail. If that is true, the fragmentation index indicates
573 * whether external fragmentation or a lack of memory was the problem.
574 * The value can be used to determine if page reclaim or compaction
575 * should be used
577 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
579 unsigned long requested = 1UL << order;
581 if (!info->free_blocks_total)
582 return 0;
584 /* Fragmentation index only makes sense when a request would fail */
585 if (info->free_blocks_suitable)
586 return -1000;
589 * Index is between 0 and 1 so return within 3 decimal places
591 * 0 => allocation would fail due to lack of memory
592 * 1 => allocation would fail due to fragmentation
594 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
597 /* Same as __fragmentation index but allocs contig_page_info on stack */
598 int fragmentation_index(struct zone *zone, unsigned int order)
600 struct contig_page_info info;
602 fill_contig_page_info(zone, order, &info);
603 return __fragmentation_index(order, &info);
605 #endif
607 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
608 #include <linux/proc_fs.h>
609 #include <linux/seq_file.h>
611 static char * const migratetype_names[MIGRATE_TYPES] = {
612 "Unmovable",
613 "Reclaimable",
614 "Movable",
615 "Reserve",
616 "Isolate",
619 static void *frag_start(struct seq_file *m, loff_t *pos)
621 pg_data_t *pgdat;
622 loff_t node = *pos;
623 for (pgdat = first_online_pgdat();
624 pgdat && node;
625 pgdat = next_online_pgdat(pgdat))
626 --node;
628 return pgdat;
631 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
633 pg_data_t *pgdat = (pg_data_t *)arg;
635 (*pos)++;
636 return next_online_pgdat(pgdat);
639 static void frag_stop(struct seq_file *m, void *arg)
643 /* Walk all the zones in a node and print using a callback */
644 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
645 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
647 struct zone *zone;
648 struct zone *node_zones = pgdat->node_zones;
649 unsigned long flags;
651 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
652 if (!populated_zone(zone))
653 continue;
655 spin_lock_irqsave(&zone->lock, flags);
656 print(m, pgdat, zone);
657 spin_unlock_irqrestore(&zone->lock, flags);
660 #endif
662 #ifdef CONFIG_PROC_FS
663 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
664 struct zone *zone)
666 int order;
668 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
669 for (order = 0; order < MAX_ORDER; ++order)
670 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
671 seq_putc(m, '\n');
675 * This walks the free areas for each zone.
677 static int frag_show(struct seq_file *m, void *arg)
679 pg_data_t *pgdat = (pg_data_t *)arg;
680 walk_zones_in_node(m, pgdat, frag_show_print);
681 return 0;
684 static void pagetypeinfo_showfree_print(struct seq_file *m,
685 pg_data_t *pgdat, struct zone *zone)
687 int order, mtype;
689 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
690 seq_printf(m, "Node %4d, zone %8s, type %12s ",
691 pgdat->node_id,
692 zone->name,
693 migratetype_names[mtype]);
694 for (order = 0; order < MAX_ORDER; ++order) {
695 unsigned long freecount = 0;
696 struct free_area *area;
697 struct list_head *curr;
699 area = &(zone->free_area[order]);
701 list_for_each(curr, &area->free_list[mtype])
702 freecount++;
703 seq_printf(m, "%6lu ", freecount);
705 seq_putc(m, '\n');
709 /* Print out the free pages at each order for each migatetype */
710 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
712 int order;
713 pg_data_t *pgdat = (pg_data_t *)arg;
715 /* Print header */
716 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
717 for (order = 0; order < MAX_ORDER; ++order)
718 seq_printf(m, "%6d ", order);
719 seq_putc(m, '\n');
721 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
723 return 0;
726 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
727 pg_data_t *pgdat, struct zone *zone)
729 int mtype;
730 unsigned long pfn;
731 unsigned long start_pfn = zone->zone_start_pfn;
732 unsigned long end_pfn = start_pfn + zone->spanned_pages;
733 unsigned long count[MIGRATE_TYPES] = { 0, };
735 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
736 struct page *page;
738 if (!pfn_valid(pfn))
739 continue;
741 page = pfn_to_page(pfn);
743 /* Watch for unexpected holes punched in the memmap */
744 if (!memmap_valid_within(pfn, page, zone))
745 continue;
747 mtype = get_pageblock_migratetype(page);
749 if (mtype < MIGRATE_TYPES)
750 count[mtype]++;
753 /* Print counts */
754 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
755 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
756 seq_printf(m, "%12lu ", count[mtype]);
757 seq_putc(m, '\n');
760 /* Print out the free pages at each order for each migratetype */
761 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
763 int mtype;
764 pg_data_t *pgdat = (pg_data_t *)arg;
766 seq_printf(m, "\n%-23s", "Number of blocks type ");
767 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
768 seq_printf(m, "%12s ", migratetype_names[mtype]);
769 seq_putc(m, '\n');
770 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
772 return 0;
776 * This prints out statistics in relation to grouping pages by mobility.
777 * It is expensive to collect so do not constantly read the file.
779 static int pagetypeinfo_show(struct seq_file *m, void *arg)
781 pg_data_t *pgdat = (pg_data_t *)arg;
783 /* check memoryless node */
784 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
785 return 0;
787 seq_printf(m, "Page block order: %d\n", pageblock_order);
788 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
789 seq_putc(m, '\n');
790 pagetypeinfo_showfree(m, pgdat);
791 pagetypeinfo_showblockcount(m, pgdat);
793 return 0;
796 static const struct seq_operations fragmentation_op = {
797 .start = frag_start,
798 .next = frag_next,
799 .stop = frag_stop,
800 .show = frag_show,
803 static int fragmentation_open(struct inode *inode, struct file *file)
805 return seq_open(file, &fragmentation_op);
808 static const struct file_operations fragmentation_file_operations = {
809 .open = fragmentation_open,
810 .read = seq_read,
811 .llseek = seq_lseek,
812 .release = seq_release,
815 static const struct seq_operations pagetypeinfo_op = {
816 .start = frag_start,
817 .next = frag_next,
818 .stop = frag_stop,
819 .show = pagetypeinfo_show,
822 static int pagetypeinfo_open(struct inode *inode, struct file *file)
824 return seq_open(file, &pagetypeinfo_op);
827 static const struct file_operations pagetypeinfo_file_ops = {
828 .open = pagetypeinfo_open,
829 .read = seq_read,
830 .llseek = seq_lseek,
831 .release = seq_release,
834 #ifdef CONFIG_ZONE_DMA
835 #define TEXT_FOR_DMA(xx) xx "_dma",
836 #else
837 #define TEXT_FOR_DMA(xx)
838 #endif
840 #ifdef CONFIG_ZONE_DMA32
841 #define TEXT_FOR_DMA32(xx) xx "_dma32",
842 #else
843 #define TEXT_FOR_DMA32(xx)
844 #endif
846 #ifdef CONFIG_HIGHMEM
847 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
848 #else
849 #define TEXT_FOR_HIGHMEM(xx)
850 #endif
852 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
853 TEXT_FOR_HIGHMEM(xx) xx "_movable",
855 static const char * const vmstat_text[] = {
856 /* Zoned VM counters */
857 "nr_free_pages",
858 "nr_inactive_anon",
859 "nr_active_anon",
860 "nr_inactive_file",
861 "nr_active_file",
862 "nr_unevictable",
863 "nr_mlock",
864 "nr_anon_pages",
865 "nr_mapped",
866 "nr_file_pages",
867 "nr_dirty",
868 "nr_writeback",
869 "nr_slab_reclaimable",
870 "nr_slab_unreclaimable",
871 "nr_page_table_pages",
872 "nr_kernel_stack",
873 "nr_unstable",
874 "nr_bounce",
875 "nr_vmscan_write",
876 "nr_writeback_temp",
877 "nr_isolated_anon",
878 "nr_isolated_file",
879 "nr_shmem",
880 "nr_dirtied",
881 "nr_written",
883 #ifdef CONFIG_NUMA
884 "numa_hit",
885 "numa_miss",
886 "numa_foreign",
887 "numa_interleave",
888 "numa_local",
889 "numa_other",
890 #endif
891 "nr_anon_transparent_hugepages",
892 "nr_dirty_threshold",
893 "nr_dirty_background_threshold",
895 #ifdef CONFIG_VM_EVENT_COUNTERS
896 "pgpgin",
897 "pgpgout",
898 "pswpin",
899 "pswpout",
901 TEXTS_FOR_ZONES("pgalloc")
903 "pgfree",
904 "pgactivate",
905 "pgdeactivate",
907 "pgfault",
908 "pgmajfault",
910 TEXTS_FOR_ZONES("pgrefill")
911 TEXTS_FOR_ZONES("pgsteal")
912 TEXTS_FOR_ZONES("pgscan_kswapd")
913 TEXTS_FOR_ZONES("pgscan_direct")
915 #ifdef CONFIG_NUMA
916 "zone_reclaim_failed",
917 #endif
918 "pginodesteal",
919 "slabs_scanned",
920 "kswapd_steal",
921 "kswapd_inodesteal",
922 "kswapd_low_wmark_hit_quickly",
923 "kswapd_high_wmark_hit_quickly",
924 "kswapd_skip_congestion_wait",
925 "pageoutrun",
926 "allocstall",
928 "pgrotated",
930 #ifdef CONFIG_COMPACTION
931 "compact_blocks_moved",
932 "compact_pages_moved",
933 "compact_pagemigrate_failed",
934 "compact_stall",
935 "compact_fail",
936 "compact_success",
937 #endif
939 #ifdef CONFIG_HUGETLB_PAGE
940 "htlb_buddy_alloc_success",
941 "htlb_buddy_alloc_fail",
942 #endif
943 "unevictable_pgs_culled",
944 "unevictable_pgs_scanned",
945 "unevictable_pgs_rescued",
946 "unevictable_pgs_mlocked",
947 "unevictable_pgs_munlocked",
948 "unevictable_pgs_cleared",
949 "unevictable_pgs_stranded",
950 "unevictable_pgs_mlockfreed",
952 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
953 "thp_fault_alloc",
954 "thp_fault_fallback",
955 "thp_collapse_alloc",
956 "thp_collapse_alloc_failed",
957 "thp_split",
958 #endif
960 #endif /* CONFIG_VM_EVENTS_COUNTERS */
963 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
964 struct zone *zone)
966 int i;
967 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
968 seq_printf(m,
969 "\n pages free %lu"
970 "\n min %lu"
971 "\n low %lu"
972 "\n high %lu"
973 "\n scanned %lu"
974 "\n spanned %lu"
975 "\n present %lu",
976 zone_page_state(zone, NR_FREE_PAGES),
977 min_wmark_pages(zone),
978 low_wmark_pages(zone),
979 high_wmark_pages(zone),
980 zone->pages_scanned,
981 zone->spanned_pages,
982 zone->present_pages);
984 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
985 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
986 zone_page_state(zone, i));
988 seq_printf(m,
989 "\n protection: (%lu",
990 zone->lowmem_reserve[0]);
991 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
992 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
993 seq_printf(m,
995 "\n pagesets");
996 for_each_online_cpu(i) {
997 struct per_cpu_pageset *pageset;
999 pageset = per_cpu_ptr(zone->pageset, i);
1000 seq_printf(m,
1001 "\n cpu: %i"
1002 "\n count: %i"
1003 "\n high: %i"
1004 "\n batch: %i",
1006 pageset->pcp.count,
1007 pageset->pcp.high,
1008 pageset->pcp.batch);
1009 #ifdef CONFIG_SMP
1010 seq_printf(m, "\n vm stats threshold: %d",
1011 pageset->stat_threshold);
1012 #endif
1014 seq_printf(m,
1015 "\n all_unreclaimable: %u"
1016 "\n start_pfn: %lu"
1017 "\n inactive_ratio: %u",
1018 zone->all_unreclaimable,
1019 zone->zone_start_pfn,
1020 zone->inactive_ratio);
1021 seq_putc(m, '\n');
1025 * Output information about zones in @pgdat.
1027 static int zoneinfo_show(struct seq_file *m, void *arg)
1029 pg_data_t *pgdat = (pg_data_t *)arg;
1030 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1031 return 0;
1034 static const struct seq_operations zoneinfo_op = {
1035 .start = frag_start, /* iterate over all zones. The same as in
1036 * fragmentation. */
1037 .next = frag_next,
1038 .stop = frag_stop,
1039 .show = zoneinfo_show,
1042 static int zoneinfo_open(struct inode *inode, struct file *file)
1044 return seq_open(file, &zoneinfo_op);
1047 static const struct file_operations proc_zoneinfo_file_operations = {
1048 .open = zoneinfo_open,
1049 .read = seq_read,
1050 .llseek = seq_lseek,
1051 .release = seq_release,
1054 enum writeback_stat_item {
1055 NR_DIRTY_THRESHOLD,
1056 NR_DIRTY_BG_THRESHOLD,
1057 NR_VM_WRITEBACK_STAT_ITEMS,
1060 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1062 unsigned long *v;
1063 int i, stat_items_size;
1065 if (*pos >= ARRAY_SIZE(vmstat_text))
1066 return NULL;
1067 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1068 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1070 #ifdef CONFIG_VM_EVENT_COUNTERS
1071 stat_items_size += sizeof(struct vm_event_state);
1072 #endif
1074 v = kmalloc(stat_items_size, GFP_KERNEL);
1075 m->private = v;
1076 if (!v)
1077 return ERR_PTR(-ENOMEM);
1078 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1079 v[i] = global_page_state(i);
1080 v += NR_VM_ZONE_STAT_ITEMS;
1082 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1083 v + NR_DIRTY_THRESHOLD);
1084 v += NR_VM_WRITEBACK_STAT_ITEMS;
1086 #ifdef CONFIG_VM_EVENT_COUNTERS
1087 all_vm_events(v);
1088 v[PGPGIN] /= 2; /* sectors -> kbytes */
1089 v[PGPGOUT] /= 2;
1090 #endif
1091 return (unsigned long *)m->private + *pos;
1094 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1096 (*pos)++;
1097 if (*pos >= ARRAY_SIZE(vmstat_text))
1098 return NULL;
1099 return (unsigned long *)m->private + *pos;
1102 static int vmstat_show(struct seq_file *m, void *arg)
1104 unsigned long *l = arg;
1105 unsigned long off = l - (unsigned long *)m->private;
1107 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1108 return 0;
1111 static void vmstat_stop(struct seq_file *m, void *arg)
1113 kfree(m->private);
1114 m->private = NULL;
1117 static const struct seq_operations vmstat_op = {
1118 .start = vmstat_start,
1119 .next = vmstat_next,
1120 .stop = vmstat_stop,
1121 .show = vmstat_show,
1124 static int vmstat_open(struct inode *inode, struct file *file)
1126 return seq_open(file, &vmstat_op);
1129 static const struct file_operations proc_vmstat_file_operations = {
1130 .open = vmstat_open,
1131 .read = seq_read,
1132 .llseek = seq_lseek,
1133 .release = seq_release,
1135 #endif /* CONFIG_PROC_FS */
1137 #ifdef CONFIG_SMP
1138 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1139 int sysctl_stat_interval __read_mostly = HZ;
1141 static void vmstat_update(struct work_struct *w)
1143 refresh_cpu_vm_stats(smp_processor_id());
1144 schedule_delayed_work(&__get_cpu_var(vmstat_work),
1145 round_jiffies_relative(sysctl_stat_interval));
1148 static void __cpuinit start_cpu_timer(int cpu)
1150 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1152 INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1153 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1157 * Use the cpu notifier to insure that the thresholds are recalculated
1158 * when necessary.
1160 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1161 unsigned long action,
1162 void *hcpu)
1164 long cpu = (long)hcpu;
1166 switch (action) {
1167 case CPU_ONLINE:
1168 case CPU_ONLINE_FROZEN:
1169 refresh_zone_stat_thresholds();
1170 start_cpu_timer(cpu);
1171 node_set_state(cpu_to_node(cpu), N_CPU);
1172 break;
1173 case CPU_DOWN_PREPARE:
1174 case CPU_DOWN_PREPARE_FROZEN:
1175 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1176 per_cpu(vmstat_work, cpu).work.func = NULL;
1177 break;
1178 case CPU_DOWN_FAILED:
1179 case CPU_DOWN_FAILED_FROZEN:
1180 start_cpu_timer(cpu);
1181 break;
1182 case CPU_DEAD:
1183 case CPU_DEAD_FROZEN:
1184 refresh_zone_stat_thresholds();
1185 break;
1186 default:
1187 break;
1189 return NOTIFY_OK;
1192 static struct notifier_block __cpuinitdata vmstat_notifier =
1193 { &vmstat_cpuup_callback, NULL, 0 };
1194 #endif
1196 static int __init setup_vmstat(void)
1198 #ifdef CONFIG_SMP
1199 int cpu;
1201 refresh_zone_stat_thresholds();
1202 register_cpu_notifier(&vmstat_notifier);
1204 for_each_online_cpu(cpu)
1205 start_cpu_timer(cpu);
1206 #endif
1207 #ifdef CONFIG_PROC_FS
1208 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1209 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1210 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1211 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1212 #endif
1213 return 0;
1215 module_init(setup_vmstat)
1217 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1218 #include <linux/debugfs.h>
1220 static struct dentry *extfrag_debug_root;
1223 * Return an index indicating how much of the available free memory is
1224 * unusable for an allocation of the requested size.
1226 static int unusable_free_index(unsigned int order,
1227 struct contig_page_info *info)
1229 /* No free memory is interpreted as all free memory is unusable */
1230 if (info->free_pages == 0)
1231 return 1000;
1234 * Index should be a value between 0 and 1. Return a value to 3
1235 * decimal places.
1237 * 0 => no fragmentation
1238 * 1 => high fragmentation
1240 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1244 static void unusable_show_print(struct seq_file *m,
1245 pg_data_t *pgdat, struct zone *zone)
1247 unsigned int order;
1248 int index;
1249 struct contig_page_info info;
1251 seq_printf(m, "Node %d, zone %8s ",
1252 pgdat->node_id,
1253 zone->name);
1254 for (order = 0; order < MAX_ORDER; ++order) {
1255 fill_contig_page_info(zone, order, &info);
1256 index = unusable_free_index(order, &info);
1257 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1260 seq_putc(m, '\n');
1264 * Display unusable free space index
1266 * The unusable free space index measures how much of the available free
1267 * memory cannot be used to satisfy an allocation of a given size and is a
1268 * value between 0 and 1. The higher the value, the more of free memory is
1269 * unusable and by implication, the worse the external fragmentation is. This
1270 * can be expressed as a percentage by multiplying by 100.
1272 static int unusable_show(struct seq_file *m, void *arg)
1274 pg_data_t *pgdat = (pg_data_t *)arg;
1276 /* check memoryless node */
1277 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1278 return 0;
1280 walk_zones_in_node(m, pgdat, unusable_show_print);
1282 return 0;
1285 static const struct seq_operations unusable_op = {
1286 .start = frag_start,
1287 .next = frag_next,
1288 .stop = frag_stop,
1289 .show = unusable_show,
1292 static int unusable_open(struct inode *inode, struct file *file)
1294 return seq_open(file, &unusable_op);
1297 static const struct file_operations unusable_file_ops = {
1298 .open = unusable_open,
1299 .read = seq_read,
1300 .llseek = seq_lseek,
1301 .release = seq_release,
1304 static void extfrag_show_print(struct seq_file *m,
1305 pg_data_t *pgdat, struct zone *zone)
1307 unsigned int order;
1308 int index;
1310 /* Alloc on stack as interrupts are disabled for zone walk */
1311 struct contig_page_info info;
1313 seq_printf(m, "Node %d, zone %8s ",
1314 pgdat->node_id,
1315 zone->name);
1316 for (order = 0; order < MAX_ORDER; ++order) {
1317 fill_contig_page_info(zone, order, &info);
1318 index = __fragmentation_index(order, &info);
1319 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1322 seq_putc(m, '\n');
1326 * Display fragmentation index for orders that allocations would fail for
1328 static int extfrag_show(struct seq_file *m, void *arg)
1330 pg_data_t *pgdat = (pg_data_t *)arg;
1332 walk_zones_in_node(m, pgdat, extfrag_show_print);
1334 return 0;
1337 static const struct seq_operations extfrag_op = {
1338 .start = frag_start,
1339 .next = frag_next,
1340 .stop = frag_stop,
1341 .show = extfrag_show,
1344 static int extfrag_open(struct inode *inode, struct file *file)
1346 return seq_open(file, &extfrag_op);
1349 static const struct file_operations extfrag_file_ops = {
1350 .open = extfrag_open,
1351 .read = seq_read,
1352 .llseek = seq_lseek,
1353 .release = seq_release,
1356 static int __init extfrag_debug_init(void)
1358 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1359 if (!extfrag_debug_root)
1360 return -ENOMEM;
1362 if (!debugfs_create_file("unusable_index", 0444,
1363 extfrag_debug_root, NULL, &unusable_file_ops))
1364 return -ENOMEM;
1366 if (!debugfs_create_file("extfrag_index", 0444,
1367 extfrag_debug_root, NULL, &extfrag_file_ops))
1368 return -ENOMEM;
1370 return 0;
1373 module_init(extfrag_debug_init);
1374 #endif