iwlegacy: remove sync_cmd_mutex
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / vmstat.c
blob772b39b87d955078b4f0d7a1b7114751e0ef9a74
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 following
325 * will apply the threshold again and therefore bring the
326 * counter under the threshold.
328 t = this_cpu_read(pcp->stat_threshold);
330 o = this_cpu_read(*p);
331 n = delta + o;
333 if (n > t || n < -t) {
334 int os = overstep_mode * (t >> 1) ;
336 /* Overflow must be added to zone counters */
337 z = n + os;
338 n = -os;
340 } while (this_cpu_cmpxchg(*p, o, n) != o);
342 if (z)
343 zone_page_state_add(z, zone, item);
346 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
347 int delta)
349 mod_state(zone, item, delta, 0);
351 EXPORT_SYMBOL(mod_zone_page_state);
353 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
355 mod_state(zone, item, 1, 1);
358 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
360 mod_state(page_zone(page), item, 1, 1);
362 EXPORT_SYMBOL(inc_zone_page_state);
364 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
366 mod_state(page_zone(page), item, -1, -1);
368 EXPORT_SYMBOL(dec_zone_page_state);
369 #else
371 * Use interrupt disable to serialize counter updates
373 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
374 int delta)
376 unsigned long flags;
378 local_irq_save(flags);
379 __mod_zone_page_state(zone, item, delta);
380 local_irq_restore(flags);
382 EXPORT_SYMBOL(mod_zone_page_state);
384 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
386 unsigned long flags;
388 local_irq_save(flags);
389 __inc_zone_state(zone, item);
390 local_irq_restore(flags);
393 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
395 unsigned long flags;
396 struct zone *zone;
398 zone = page_zone(page);
399 local_irq_save(flags);
400 __inc_zone_state(zone, item);
401 local_irq_restore(flags);
403 EXPORT_SYMBOL(inc_zone_page_state);
405 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
407 unsigned long flags;
409 local_irq_save(flags);
410 __dec_zone_page_state(page, item);
411 local_irq_restore(flags);
413 EXPORT_SYMBOL(dec_zone_page_state);
414 #endif
417 * Update the zone counters for one cpu.
419 * The cpu specified must be either the current cpu or a processor that
420 * is not online. If it is the current cpu then the execution thread must
421 * be pinned to the current cpu.
423 * Note that refresh_cpu_vm_stats strives to only access
424 * node local memory. The per cpu pagesets on remote zones are placed
425 * in the memory local to the processor using that pageset. So the
426 * loop over all zones will access a series of cachelines local to
427 * the processor.
429 * The call to zone_page_state_add updates the cachelines with the
430 * statistics in the remote zone struct as well as the global cachelines
431 * with the global counters. These could cause remote node cache line
432 * bouncing and will have to be only done when necessary.
434 void refresh_cpu_vm_stats(int cpu)
436 struct zone *zone;
437 int i;
438 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
440 for_each_populated_zone(zone) {
441 struct per_cpu_pageset *p;
443 p = per_cpu_ptr(zone->pageset, cpu);
445 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
446 if (p->vm_stat_diff[i]) {
447 unsigned long flags;
448 int v;
450 local_irq_save(flags);
451 v = p->vm_stat_diff[i];
452 p->vm_stat_diff[i] = 0;
453 local_irq_restore(flags);
454 atomic_long_add(v, &zone->vm_stat[i]);
455 global_diff[i] += v;
456 #ifdef CONFIG_NUMA
457 /* 3 seconds idle till flush */
458 p->expire = 3;
459 #endif
461 cond_resched();
462 #ifdef CONFIG_NUMA
464 * Deal with draining the remote pageset of this
465 * processor
467 * Check if there are pages remaining in this pageset
468 * if not then there is nothing to expire.
470 if (!p->expire || !p->pcp.count)
471 continue;
474 * We never drain zones local to this processor.
476 if (zone_to_nid(zone) == numa_node_id()) {
477 p->expire = 0;
478 continue;
481 p->expire--;
482 if (p->expire)
483 continue;
485 if (p->pcp.count)
486 drain_zone_pages(zone, &p->pcp);
487 #endif
490 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
491 if (global_diff[i])
492 atomic_long_add(global_diff[i], &vm_stat[i]);
495 #endif
497 #ifdef CONFIG_NUMA
499 * zonelist = the list of zones passed to the allocator
500 * z = the zone from which the allocation occurred.
502 * Must be called with interrupts disabled.
504 * When __GFP_OTHER_NODE is set assume the node of the preferred
505 * zone is the local node. This is useful for daemons who allocate
506 * memory on behalf of other processes.
508 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
510 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
511 __inc_zone_state(z, NUMA_HIT);
512 } else {
513 __inc_zone_state(z, NUMA_MISS);
514 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
516 if (z->node == ((flags & __GFP_OTHER_NODE) ?
517 preferred_zone->node : numa_node_id()))
518 __inc_zone_state(z, NUMA_LOCAL);
519 else
520 __inc_zone_state(z, NUMA_OTHER);
522 #endif
524 #ifdef CONFIG_COMPACTION
526 struct contig_page_info {
527 unsigned long free_pages;
528 unsigned long free_blocks_total;
529 unsigned long free_blocks_suitable;
533 * Calculate the number of free pages in a zone, how many contiguous
534 * pages are free and how many are large enough to satisfy an allocation of
535 * the target size. Note that this function makes no attempt to estimate
536 * how many suitable free blocks there *might* be if MOVABLE pages were
537 * migrated. Calculating that is possible, but expensive and can be
538 * figured out from userspace
540 static void fill_contig_page_info(struct zone *zone,
541 unsigned int suitable_order,
542 struct contig_page_info *info)
544 unsigned int order;
546 info->free_pages = 0;
547 info->free_blocks_total = 0;
548 info->free_blocks_suitable = 0;
550 for (order = 0; order < MAX_ORDER; order++) {
551 unsigned long blocks;
553 /* Count number of free blocks */
554 blocks = zone->free_area[order].nr_free;
555 info->free_blocks_total += blocks;
557 /* Count free base pages */
558 info->free_pages += blocks << order;
560 /* Count the suitable free blocks */
561 if (order >= suitable_order)
562 info->free_blocks_suitable += blocks <<
563 (order - suitable_order);
568 * A fragmentation index only makes sense if an allocation of a requested
569 * size would fail. If that is true, the fragmentation index indicates
570 * whether external fragmentation or a lack of memory was the problem.
571 * The value can be used to determine if page reclaim or compaction
572 * should be used
574 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
576 unsigned long requested = 1UL << order;
578 if (!info->free_blocks_total)
579 return 0;
581 /* Fragmentation index only makes sense when a request would fail */
582 if (info->free_blocks_suitable)
583 return -1000;
586 * Index is between 0 and 1 so return within 3 decimal places
588 * 0 => allocation would fail due to lack of memory
589 * 1 => allocation would fail due to fragmentation
591 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
594 /* Same as __fragmentation index but allocs contig_page_info on stack */
595 int fragmentation_index(struct zone *zone, unsigned int order)
597 struct contig_page_info info;
599 fill_contig_page_info(zone, order, &info);
600 return __fragmentation_index(order, &info);
602 #endif
604 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
605 #include <linux/proc_fs.h>
606 #include <linux/seq_file.h>
608 static char * const migratetype_names[MIGRATE_TYPES] = {
609 "Unmovable",
610 "Reclaimable",
611 "Movable",
612 "Reserve",
613 "Isolate",
616 static void *frag_start(struct seq_file *m, loff_t *pos)
618 pg_data_t *pgdat;
619 loff_t node = *pos;
620 for (pgdat = first_online_pgdat();
621 pgdat && node;
622 pgdat = next_online_pgdat(pgdat))
623 --node;
625 return pgdat;
628 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
630 pg_data_t *pgdat = (pg_data_t *)arg;
632 (*pos)++;
633 return next_online_pgdat(pgdat);
636 static void frag_stop(struct seq_file *m, void *arg)
640 /* Walk all the zones in a node and print using a callback */
641 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
642 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
644 struct zone *zone;
645 struct zone *node_zones = pgdat->node_zones;
646 unsigned long flags;
648 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
649 if (!populated_zone(zone))
650 continue;
652 spin_lock_irqsave(&zone->lock, flags);
653 print(m, pgdat, zone);
654 spin_unlock_irqrestore(&zone->lock, flags);
657 #endif
659 #ifdef CONFIG_PROC_FS
660 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
661 struct zone *zone)
663 int order;
665 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
666 for (order = 0; order < MAX_ORDER; ++order)
667 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
668 seq_putc(m, '\n');
672 * This walks the free areas for each zone.
674 static int frag_show(struct seq_file *m, void *arg)
676 pg_data_t *pgdat = (pg_data_t *)arg;
677 walk_zones_in_node(m, pgdat, frag_show_print);
678 return 0;
681 static void pagetypeinfo_showfree_print(struct seq_file *m,
682 pg_data_t *pgdat, struct zone *zone)
684 int order, mtype;
686 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
687 seq_printf(m, "Node %4d, zone %8s, type %12s ",
688 pgdat->node_id,
689 zone->name,
690 migratetype_names[mtype]);
691 for (order = 0; order < MAX_ORDER; ++order) {
692 unsigned long freecount = 0;
693 struct free_area *area;
694 struct list_head *curr;
696 area = &(zone->free_area[order]);
698 list_for_each(curr, &area->free_list[mtype])
699 freecount++;
700 seq_printf(m, "%6lu ", freecount);
702 seq_putc(m, '\n');
706 /* Print out the free pages at each order for each migatetype */
707 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
709 int order;
710 pg_data_t *pgdat = (pg_data_t *)arg;
712 /* Print header */
713 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
714 for (order = 0; order < MAX_ORDER; ++order)
715 seq_printf(m, "%6d ", order);
716 seq_putc(m, '\n');
718 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
720 return 0;
723 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
724 pg_data_t *pgdat, struct zone *zone)
726 int mtype;
727 unsigned long pfn;
728 unsigned long start_pfn = zone->zone_start_pfn;
729 unsigned long end_pfn = start_pfn + zone->spanned_pages;
730 unsigned long count[MIGRATE_TYPES] = { 0, };
732 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
733 struct page *page;
735 if (!pfn_valid(pfn))
736 continue;
738 page = pfn_to_page(pfn);
740 /* Watch for unexpected holes punched in the memmap */
741 if (!memmap_valid_within(pfn, page, zone))
742 continue;
744 mtype = get_pageblock_migratetype(page);
746 if (mtype < MIGRATE_TYPES)
747 count[mtype]++;
750 /* Print counts */
751 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
752 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
753 seq_printf(m, "%12lu ", count[mtype]);
754 seq_putc(m, '\n');
757 /* Print out the free pages at each order for each migratetype */
758 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
760 int mtype;
761 pg_data_t *pgdat = (pg_data_t *)arg;
763 seq_printf(m, "\n%-23s", "Number of blocks type ");
764 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
765 seq_printf(m, "%12s ", migratetype_names[mtype]);
766 seq_putc(m, '\n');
767 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
769 return 0;
773 * This prints out statistics in relation to grouping pages by mobility.
774 * It is expensive to collect so do not constantly read the file.
776 static int pagetypeinfo_show(struct seq_file *m, void *arg)
778 pg_data_t *pgdat = (pg_data_t *)arg;
780 /* check memoryless node */
781 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
782 return 0;
784 seq_printf(m, "Page block order: %d\n", pageblock_order);
785 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
786 seq_putc(m, '\n');
787 pagetypeinfo_showfree(m, pgdat);
788 pagetypeinfo_showblockcount(m, pgdat);
790 return 0;
793 static const struct seq_operations fragmentation_op = {
794 .start = frag_start,
795 .next = frag_next,
796 .stop = frag_stop,
797 .show = frag_show,
800 static int fragmentation_open(struct inode *inode, struct file *file)
802 return seq_open(file, &fragmentation_op);
805 static const struct file_operations fragmentation_file_operations = {
806 .open = fragmentation_open,
807 .read = seq_read,
808 .llseek = seq_lseek,
809 .release = seq_release,
812 static const struct seq_operations pagetypeinfo_op = {
813 .start = frag_start,
814 .next = frag_next,
815 .stop = frag_stop,
816 .show = pagetypeinfo_show,
819 static int pagetypeinfo_open(struct inode *inode, struct file *file)
821 return seq_open(file, &pagetypeinfo_op);
824 static const struct file_operations pagetypeinfo_file_ops = {
825 .open = pagetypeinfo_open,
826 .read = seq_read,
827 .llseek = seq_lseek,
828 .release = seq_release,
831 #ifdef CONFIG_ZONE_DMA
832 #define TEXT_FOR_DMA(xx) xx "_dma",
833 #else
834 #define TEXT_FOR_DMA(xx)
835 #endif
837 #ifdef CONFIG_ZONE_DMA32
838 #define TEXT_FOR_DMA32(xx) xx "_dma32",
839 #else
840 #define TEXT_FOR_DMA32(xx)
841 #endif
843 #ifdef CONFIG_HIGHMEM
844 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
845 #else
846 #define TEXT_FOR_HIGHMEM(xx)
847 #endif
849 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
850 TEXT_FOR_HIGHMEM(xx) xx "_movable",
852 static const char * const vmstat_text[] = {
853 /* Zoned VM counters */
854 "nr_free_pages",
855 "nr_inactive_anon",
856 "nr_active_anon",
857 "nr_inactive_file",
858 "nr_active_file",
859 "nr_unevictable",
860 "nr_mlock",
861 "nr_anon_pages",
862 "nr_mapped",
863 "nr_file_pages",
864 "nr_dirty",
865 "nr_writeback",
866 "nr_slab_reclaimable",
867 "nr_slab_unreclaimable",
868 "nr_page_table_pages",
869 "nr_kernel_stack",
870 "nr_unstable",
871 "nr_bounce",
872 "nr_vmscan_write",
873 "nr_writeback_temp",
874 "nr_isolated_anon",
875 "nr_isolated_file",
876 "nr_shmem",
877 "nr_dirtied",
878 "nr_written",
880 #ifdef CONFIG_NUMA
881 "numa_hit",
882 "numa_miss",
883 "numa_foreign",
884 "numa_interleave",
885 "numa_local",
886 "numa_other",
887 #endif
888 "nr_anon_transparent_hugepages",
889 "nr_dirty_threshold",
890 "nr_dirty_background_threshold",
892 #ifdef CONFIG_VM_EVENT_COUNTERS
893 "pgpgin",
894 "pgpgout",
895 "pswpin",
896 "pswpout",
898 TEXTS_FOR_ZONES("pgalloc")
900 "pgfree",
901 "pgactivate",
902 "pgdeactivate",
904 "pgfault",
905 "pgmajfault",
907 TEXTS_FOR_ZONES("pgrefill")
908 TEXTS_FOR_ZONES("pgsteal")
909 TEXTS_FOR_ZONES("pgscan_kswapd")
910 TEXTS_FOR_ZONES("pgscan_direct")
912 #ifdef CONFIG_NUMA
913 "zone_reclaim_failed",
914 #endif
915 "pginodesteal",
916 "slabs_scanned",
917 "kswapd_steal",
918 "kswapd_inodesteal",
919 "kswapd_low_wmark_hit_quickly",
920 "kswapd_high_wmark_hit_quickly",
921 "kswapd_skip_congestion_wait",
922 "pageoutrun",
923 "allocstall",
925 "pgrotated",
927 #ifdef CONFIG_COMPACTION
928 "compact_blocks_moved",
929 "compact_pages_moved",
930 "compact_pagemigrate_failed",
931 "compact_stall",
932 "compact_fail",
933 "compact_success",
934 #endif
936 #ifdef CONFIG_HUGETLB_PAGE
937 "htlb_buddy_alloc_success",
938 "htlb_buddy_alloc_fail",
939 #endif
940 "unevictable_pgs_culled",
941 "unevictable_pgs_scanned",
942 "unevictable_pgs_rescued",
943 "unevictable_pgs_mlocked",
944 "unevictable_pgs_munlocked",
945 "unevictable_pgs_cleared",
946 "unevictable_pgs_stranded",
947 "unevictable_pgs_mlockfreed",
948 #endif
951 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
952 struct zone *zone)
954 int i;
955 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
956 seq_printf(m,
957 "\n pages free %lu"
958 "\n min %lu"
959 "\n low %lu"
960 "\n high %lu"
961 "\n scanned %lu"
962 "\n spanned %lu"
963 "\n present %lu",
964 zone_page_state(zone, NR_FREE_PAGES),
965 min_wmark_pages(zone),
966 low_wmark_pages(zone),
967 high_wmark_pages(zone),
968 zone->pages_scanned,
969 zone->spanned_pages,
970 zone->present_pages);
972 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
973 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
974 zone_page_state(zone, i));
976 seq_printf(m,
977 "\n protection: (%lu",
978 zone->lowmem_reserve[0]);
979 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
980 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
981 seq_printf(m,
983 "\n pagesets");
984 for_each_online_cpu(i) {
985 struct per_cpu_pageset *pageset;
987 pageset = per_cpu_ptr(zone->pageset, i);
988 seq_printf(m,
989 "\n cpu: %i"
990 "\n count: %i"
991 "\n high: %i"
992 "\n batch: %i",
994 pageset->pcp.count,
995 pageset->pcp.high,
996 pageset->pcp.batch);
997 #ifdef CONFIG_SMP
998 seq_printf(m, "\n vm stats threshold: %d",
999 pageset->stat_threshold);
1000 #endif
1002 seq_printf(m,
1003 "\n all_unreclaimable: %u"
1004 "\n start_pfn: %lu"
1005 "\n inactive_ratio: %u",
1006 zone->all_unreclaimable,
1007 zone->zone_start_pfn,
1008 zone->inactive_ratio);
1009 seq_putc(m, '\n');
1013 * Output information about zones in @pgdat.
1015 static int zoneinfo_show(struct seq_file *m, void *arg)
1017 pg_data_t *pgdat = (pg_data_t *)arg;
1018 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1019 return 0;
1022 static const struct seq_operations zoneinfo_op = {
1023 .start = frag_start, /* iterate over all zones. The same as in
1024 * fragmentation. */
1025 .next = frag_next,
1026 .stop = frag_stop,
1027 .show = zoneinfo_show,
1030 static int zoneinfo_open(struct inode *inode, struct file *file)
1032 return seq_open(file, &zoneinfo_op);
1035 static const struct file_operations proc_zoneinfo_file_operations = {
1036 .open = zoneinfo_open,
1037 .read = seq_read,
1038 .llseek = seq_lseek,
1039 .release = seq_release,
1042 enum writeback_stat_item {
1043 NR_DIRTY_THRESHOLD,
1044 NR_DIRTY_BG_THRESHOLD,
1045 NR_VM_WRITEBACK_STAT_ITEMS,
1048 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1050 unsigned long *v;
1051 int i, stat_items_size;
1053 if (*pos >= ARRAY_SIZE(vmstat_text))
1054 return NULL;
1055 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1056 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1058 #ifdef CONFIG_VM_EVENT_COUNTERS
1059 stat_items_size += sizeof(struct vm_event_state);
1060 #endif
1062 v = kmalloc(stat_items_size, GFP_KERNEL);
1063 m->private = v;
1064 if (!v)
1065 return ERR_PTR(-ENOMEM);
1066 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1067 v[i] = global_page_state(i);
1068 v += NR_VM_ZONE_STAT_ITEMS;
1070 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1071 v + NR_DIRTY_THRESHOLD);
1072 v += NR_VM_WRITEBACK_STAT_ITEMS;
1074 #ifdef CONFIG_VM_EVENT_COUNTERS
1075 all_vm_events(v);
1076 v[PGPGIN] /= 2; /* sectors -> kbytes */
1077 v[PGPGOUT] /= 2;
1078 #endif
1079 return (unsigned long *)m->private + *pos;
1082 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1084 (*pos)++;
1085 if (*pos >= ARRAY_SIZE(vmstat_text))
1086 return NULL;
1087 return (unsigned long *)m->private + *pos;
1090 static int vmstat_show(struct seq_file *m, void *arg)
1092 unsigned long *l = arg;
1093 unsigned long off = l - (unsigned long *)m->private;
1095 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1096 return 0;
1099 static void vmstat_stop(struct seq_file *m, void *arg)
1101 kfree(m->private);
1102 m->private = NULL;
1105 static const struct seq_operations vmstat_op = {
1106 .start = vmstat_start,
1107 .next = vmstat_next,
1108 .stop = vmstat_stop,
1109 .show = vmstat_show,
1112 static int vmstat_open(struct inode *inode, struct file *file)
1114 return seq_open(file, &vmstat_op);
1117 static const struct file_operations proc_vmstat_file_operations = {
1118 .open = vmstat_open,
1119 .read = seq_read,
1120 .llseek = seq_lseek,
1121 .release = seq_release,
1123 #endif /* CONFIG_PROC_FS */
1125 #ifdef CONFIG_SMP
1126 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1127 int sysctl_stat_interval __read_mostly = HZ;
1129 static void vmstat_update(struct work_struct *w)
1131 refresh_cpu_vm_stats(smp_processor_id());
1132 schedule_delayed_work(&__get_cpu_var(vmstat_work),
1133 round_jiffies_relative(sysctl_stat_interval));
1136 static void __cpuinit start_cpu_timer(int cpu)
1138 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1140 INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1141 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1145 * Use the cpu notifier to insure that the thresholds are recalculated
1146 * when necessary.
1148 static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1149 unsigned long action,
1150 void *hcpu)
1152 long cpu = (long)hcpu;
1154 switch (action) {
1155 case CPU_ONLINE:
1156 case CPU_ONLINE_FROZEN:
1157 refresh_zone_stat_thresholds();
1158 start_cpu_timer(cpu);
1159 node_set_state(cpu_to_node(cpu), N_CPU);
1160 break;
1161 case CPU_DOWN_PREPARE:
1162 case CPU_DOWN_PREPARE_FROZEN:
1163 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1164 per_cpu(vmstat_work, cpu).work.func = NULL;
1165 break;
1166 case CPU_DOWN_FAILED:
1167 case CPU_DOWN_FAILED_FROZEN:
1168 start_cpu_timer(cpu);
1169 break;
1170 case CPU_DEAD:
1171 case CPU_DEAD_FROZEN:
1172 refresh_zone_stat_thresholds();
1173 break;
1174 default:
1175 break;
1177 return NOTIFY_OK;
1180 static struct notifier_block __cpuinitdata vmstat_notifier =
1181 { &vmstat_cpuup_callback, NULL, 0 };
1182 #endif
1184 static int __init setup_vmstat(void)
1186 #ifdef CONFIG_SMP
1187 int cpu;
1189 refresh_zone_stat_thresholds();
1190 register_cpu_notifier(&vmstat_notifier);
1192 for_each_online_cpu(cpu)
1193 start_cpu_timer(cpu);
1194 #endif
1195 #ifdef CONFIG_PROC_FS
1196 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1197 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1198 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1199 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1200 #endif
1201 return 0;
1203 module_init(setup_vmstat)
1205 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1206 #include <linux/debugfs.h>
1208 static struct dentry *extfrag_debug_root;
1211 * Return an index indicating how much of the available free memory is
1212 * unusable for an allocation of the requested size.
1214 static int unusable_free_index(unsigned int order,
1215 struct contig_page_info *info)
1217 /* No free memory is interpreted as all free memory is unusable */
1218 if (info->free_pages == 0)
1219 return 1000;
1222 * Index should be a value between 0 and 1. Return a value to 3
1223 * decimal places.
1225 * 0 => no fragmentation
1226 * 1 => high fragmentation
1228 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1232 static void unusable_show_print(struct seq_file *m,
1233 pg_data_t *pgdat, struct zone *zone)
1235 unsigned int order;
1236 int index;
1237 struct contig_page_info info;
1239 seq_printf(m, "Node %d, zone %8s ",
1240 pgdat->node_id,
1241 zone->name);
1242 for (order = 0; order < MAX_ORDER; ++order) {
1243 fill_contig_page_info(zone, order, &info);
1244 index = unusable_free_index(order, &info);
1245 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1248 seq_putc(m, '\n');
1252 * Display unusable free space index
1254 * The unusable free space index measures how much of the available free
1255 * memory cannot be used to satisfy an allocation of a given size and is a
1256 * value between 0 and 1. The higher the value, the more of free memory is
1257 * unusable and by implication, the worse the external fragmentation is. This
1258 * can be expressed as a percentage by multiplying by 100.
1260 static int unusable_show(struct seq_file *m, void *arg)
1262 pg_data_t *pgdat = (pg_data_t *)arg;
1264 /* check memoryless node */
1265 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1266 return 0;
1268 walk_zones_in_node(m, pgdat, unusable_show_print);
1270 return 0;
1273 static const struct seq_operations unusable_op = {
1274 .start = frag_start,
1275 .next = frag_next,
1276 .stop = frag_stop,
1277 .show = unusable_show,
1280 static int unusable_open(struct inode *inode, struct file *file)
1282 return seq_open(file, &unusable_op);
1285 static const struct file_operations unusable_file_ops = {
1286 .open = unusable_open,
1287 .read = seq_read,
1288 .llseek = seq_lseek,
1289 .release = seq_release,
1292 static void extfrag_show_print(struct seq_file *m,
1293 pg_data_t *pgdat, struct zone *zone)
1295 unsigned int order;
1296 int index;
1298 /* Alloc on stack as interrupts are disabled for zone walk */
1299 struct contig_page_info info;
1301 seq_printf(m, "Node %d, zone %8s ",
1302 pgdat->node_id,
1303 zone->name);
1304 for (order = 0; order < MAX_ORDER; ++order) {
1305 fill_contig_page_info(zone, order, &info);
1306 index = __fragmentation_index(order, &info);
1307 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1310 seq_putc(m, '\n');
1314 * Display fragmentation index for orders that allocations would fail for
1316 static int extfrag_show(struct seq_file *m, void *arg)
1318 pg_data_t *pgdat = (pg_data_t *)arg;
1320 walk_zones_in_node(m, pgdat, extfrag_show_print);
1322 return 0;
1325 static const struct seq_operations extfrag_op = {
1326 .start = frag_start,
1327 .next = frag_next,
1328 .stop = frag_stop,
1329 .show = extfrag_show,
1332 static int extfrag_open(struct inode *inode, struct file *file)
1334 return seq_open(file, &extfrag_op);
1337 static const struct file_operations extfrag_file_ops = {
1338 .open = extfrag_open,
1339 .read = seq_read,
1340 .llseek = seq_lseek,
1341 .release = seq_release,
1344 static int __init extfrag_debug_init(void)
1346 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1347 if (!extfrag_debug_root)
1348 return -ENOMEM;
1350 if (!debugfs_create_file("unusable_index", 0444,
1351 extfrag_debug_root, NULL, &unusable_file_ops))
1352 return -ENOMEM;
1354 if (!debugfs_create_file("extfrag_index", 0444,
1355 extfrag_debug_root, NULL, &extfrag_file_ops))
1356 return -ENOMEM;
1358 return 0;
1361 module_init(extfrag_debug_init);
1362 #endif