vmstat.c revision 08d9ae7cbbd0c5c07573d072ec771e997a9a39e0 
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/cpu.h>
16#include <linux/vmstat.h>
17#include <linux/sched.h>
18
19#ifdef CONFIG_VM_EVENT_COUNTERS
20DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
21EXPORT_PER_CPU_SYMBOL(vm_event_states);
22
23static void sum_vm_events(unsigned long *ret, const struct cpumask *cpumask)
24{
25	int cpu;
26	int i;
27
28	memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
29
30	for_each_cpu(cpu, cpumask) {
31		struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
32
33		for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
34			ret[i] += this->event[i];
35	}
36}
37
38/*
39 * Accumulate the vm event counters across all CPUs.
40 * The result is unavoidably approximate - it can change
41 * during and after execution of this function.
42*/
43void all_vm_events(unsigned long *ret)
44{
45	get_online_cpus();
46	sum_vm_events(ret, cpu_online_mask);
47	put_online_cpus();
48}
49EXPORT_SYMBOL_GPL(all_vm_events);
50
51#ifdef CONFIG_HOTPLUG
52/*
53 * Fold the foreign cpu events into our own.
54 *
55 * This is adding to the events on one processor
56 * but keeps the global counts constant.
57 */
58void vm_events_fold_cpu(int cpu)
59{
60	struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
61	int i;
62
63	for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
64		count_vm_events(i, fold_state->event[i]);
65		fold_state->event[i] = 0;
66	}
67}
68#endif /* CONFIG_HOTPLUG */
69
70#endif /* CONFIG_VM_EVENT_COUNTERS */
71
72/*
73 * Manage combined zone based / global counters
74 *
75 * vm_stat contains the global counters
76 */
77atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
78EXPORT_SYMBOL(vm_stat);
79
80#ifdef CONFIG_SMP
81
82static int calculate_threshold(struct zone *zone)
83{
84	int threshold;
85	int mem;	/* memory in 128 MB units */
86
87	/*
88	 * The threshold scales with the number of processors and the amount
89	 * of memory per zone. More memory means that we can defer updates for
90	 * longer, more processors could lead to more contention.
91 	 * fls() is used to have a cheap way of logarithmic scaling.
92	 *
93	 * Some sample thresholds:
94	 *
95	 * Threshold	Processors	(fls)	Zonesize	fls(mem+1)
96	 * ------------------------------------------------------------------
97	 * 8		1		1	0.9-1 GB	4
98	 * 16		2		2	0.9-1 GB	4
99	 * 20 		2		2	1-2 GB		5
100	 * 24		2		2	2-4 GB		6
101	 * 28		2		2	4-8 GB		7
102	 * 32		2		2	8-16 GB		8
103	 * 4		2		2	<128M		1
104	 * 30		4		3	2-4 GB		5
105	 * 48		4		3	8-16 GB		8
106	 * 32		8		4	1-2 GB		4
107	 * 32		8		4	0.9-1GB		4
108	 * 10		16		5	<128M		1
109	 * 40		16		5	900M		4
110	 * 70		64		7	2-4 GB		5
111	 * 84		64		7	4-8 GB		6
112	 * 108		512		9	4-8 GB		6
113	 * 125		1024		10	8-16 GB		8
114	 * 125		1024		10	16-32 GB	9
115	 */
116
117	mem = zone->present_pages >> (27 - PAGE_SHIFT);
118
119	threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
120
121	/*
122	 * Maximum threshold is 125
123	 */
124	threshold = min(125, threshold);
125
126	return threshold;
127}
128
129/*
130 * Refresh the thresholds for each zone.
131 */
132static void refresh_zone_stat_thresholds(void)
133{
134	struct zone *zone;
135	int cpu;
136	int threshold;
137
138	for_each_populated_zone(zone) {
139		threshold = calculate_threshold(zone);
140
141		for_each_online_cpu(cpu)
142			zone_pcp(zone, cpu)->stat_threshold = threshold;
143	}
144}
145
146/*
147 * For use when we know that interrupts are disabled.
148 */
149void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
150				int delta)
151{
152	struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
153	s8 *p = pcp->vm_stat_diff + item;
154	long x;
155
156	x = delta + *p;
157
158	if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
159		zone_page_state_add(x, zone, item);
160		x = 0;
161	}
162	*p = x;
163}
164EXPORT_SYMBOL(__mod_zone_page_state);
165
166/*
167 * For an unknown interrupt state
168 */
169void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
170					int delta)
171{
172	unsigned long flags;
173
174	local_irq_save(flags);
175	__mod_zone_page_state(zone, item, delta);
176	local_irq_restore(flags);
177}
178EXPORT_SYMBOL(mod_zone_page_state);
179
180/*
181 * Optimized increment and decrement functions.
182 *
183 * These are only for a single page and therefore can take a struct page *
184 * argument instead of struct zone *. This allows the inclusion of the code
185 * generated for page_zone(page) into the optimized functions.
186 *
187 * No overflow check is necessary and therefore the differential can be
188 * incremented or decremented in place which may allow the compilers to
189 * generate better code.
190 * The increment or decrement is known and therefore one boundary check can
191 * be omitted.
192 *
193 * NOTE: These functions are very performance sensitive. Change only
194 * with care.
195 *
196 * Some processors have inc/dec instructions that are atomic vs an interrupt.
197 * However, the code must first determine the differential location in a zone
198 * based on the processor number and then inc/dec the counter. There is no
199 * guarantee without disabling preemption that the processor will not change
200 * in between and therefore the atomicity vs. interrupt cannot be exploited
201 * in a useful way here.
202 */
203void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
204{
205	struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
206	s8 *p = pcp->vm_stat_diff + item;
207
208	(*p)++;
209
210	if (unlikely(*p > pcp->stat_threshold)) {
211		int overstep = pcp->stat_threshold / 2;
212
213		zone_page_state_add(*p + overstep, zone, item);
214		*p = -overstep;
215	}
216}
217
218void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
219{
220	__inc_zone_state(page_zone(page), item);
221}
222EXPORT_SYMBOL(__inc_zone_page_state);
223
224void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
225{
226	struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
227	s8 *p = pcp->vm_stat_diff + item;
228
229	(*p)--;
230
231	if (unlikely(*p < - pcp->stat_threshold)) {
232		int overstep = pcp->stat_threshold / 2;
233
234		zone_page_state_add(*p - overstep, zone, item);
235		*p = overstep;
236	}
237}
238
239void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
240{
241	__dec_zone_state(page_zone(page), item);
242}
243EXPORT_SYMBOL(__dec_zone_page_state);
244
245void inc_zone_state(struct zone *zone, enum zone_stat_item item)
246{
247	unsigned long flags;
248
249	local_irq_save(flags);
250	__inc_zone_state(zone, item);
251	local_irq_restore(flags);
252}
253
254void inc_zone_page_state(struct page *page, enum zone_stat_item item)
255{
256	unsigned long flags;
257	struct zone *zone;
258
259	zone = page_zone(page);
260	local_irq_save(flags);
261	__inc_zone_state(zone, item);
262	local_irq_restore(flags);
263}
264EXPORT_SYMBOL(inc_zone_page_state);
265
266void dec_zone_page_state(struct page *page, enum zone_stat_item item)
267{
268	unsigned long flags;
269
270	local_irq_save(flags);
271	__dec_zone_page_state(page, item);
272	local_irq_restore(flags);
273}
274EXPORT_SYMBOL(dec_zone_page_state);
275
276/*
277 * Update the zone counters for one cpu.
278 *
279 * The cpu specified must be either the current cpu or a processor that
280 * is not online. If it is the current cpu then the execution thread must
281 * be pinned to the current cpu.
282 *
283 * Note that refresh_cpu_vm_stats strives to only access
284 * node local memory. The per cpu pagesets on remote zones are placed
285 * in the memory local to the processor using that pageset. So the
286 * loop over all zones will access a series of cachelines local to
287 * the processor.
288 *
289 * The call to zone_page_state_add updates the cachelines with the
290 * statistics in the remote zone struct as well as the global cachelines
291 * with the global counters. These could cause remote node cache line
292 * bouncing and will have to be only done when necessary.
293 */
294void refresh_cpu_vm_stats(int cpu)
295{
296	struct zone *zone;
297	int i;
298	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
299
300	for_each_populated_zone(zone) {
301		struct per_cpu_pageset *p;
302
303		p = zone_pcp(zone, cpu);
304
305		for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
306			if (p->vm_stat_diff[i]) {
307				unsigned long flags;
308				int v;
309
310				local_irq_save(flags);
311				v = p->vm_stat_diff[i];
312				p->vm_stat_diff[i] = 0;
313				local_irq_restore(flags);
314				atomic_long_add(v, &zone->vm_stat[i]);
315				global_diff[i] += v;
316#ifdef CONFIG_NUMA
317				/* 3 seconds idle till flush */
318				p->expire = 3;
319#endif
320			}
321		cond_resched();
322#ifdef CONFIG_NUMA
323		/*
324		 * Deal with draining the remote pageset of this
325		 * processor
326		 *
327		 * Check if there are pages remaining in this pageset
328		 * if not then there is nothing to expire.
329		 */
330		if (!p->expire || !p->pcp.count)
331			continue;
332
333		/*
334		 * We never drain zones local to this processor.
335		 */
336		if (zone_to_nid(zone) == numa_node_id()) {
337			p->expire = 0;
338			continue;
339		}
340
341		p->expire--;
342		if (p->expire)
343			continue;
344
345		if (p->pcp.count)
346			drain_zone_pages(zone, &p->pcp);
347#endif
348	}
349
350	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
351		if (global_diff[i])
352			atomic_long_add(global_diff[i], &vm_stat[i]);
353}
354
355#endif
356
357#ifdef CONFIG_NUMA
358/*
359 * zonelist = the list of zones passed to the allocator
360 * z 	    = the zone from which the allocation occurred.
361 *
362 * Must be called with interrupts disabled.
363 */
364void zone_statistics(struct zone *preferred_zone, struct zone *z)
365{
366	if (z->zone_pgdat == preferred_zone->zone_pgdat) {
367		__inc_zone_state(z, NUMA_HIT);
368	} else {
369		__inc_zone_state(z, NUMA_MISS);
370		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
371	}
372	if (z->node == numa_node_id())
373		__inc_zone_state(z, NUMA_LOCAL);
374	else
375		__inc_zone_state(z, NUMA_OTHER);
376}
377#endif
378
379#ifdef CONFIG_PROC_FS
380#include <linux/proc_fs.h>
381#include <linux/seq_file.h>
382
383static char * const migratetype_names[MIGRATE_TYPES] = {
384	"Unmovable",
385	"Reclaimable",
386	"Movable",
387	"Reserve",
388	"Isolate",
389};
390
391static void *frag_start(struct seq_file *m, loff_t *pos)
392{
393	pg_data_t *pgdat;
394	loff_t node = *pos;
395	for (pgdat = first_online_pgdat();
396	     pgdat && node;
397	     pgdat = next_online_pgdat(pgdat))
398		--node;
399
400	return pgdat;
401}
402
403static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
404{
405	pg_data_t *pgdat = (pg_data_t *)arg;
406
407	(*pos)++;
408	return next_online_pgdat(pgdat);
409}
410
411static void frag_stop(struct seq_file *m, void *arg)
412{
413}
414
415/* Walk all the zones in a node and print using a callback */
416static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
417		void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
418{
419	struct zone *zone;
420	struct zone *node_zones = pgdat->node_zones;
421	unsigned long flags;
422
423	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
424		if (!populated_zone(zone))
425			continue;
426
427		spin_lock_irqsave(&zone->lock, flags);
428		print(m, pgdat, zone);
429		spin_unlock_irqrestore(&zone->lock, flags);
430	}
431}
432
433static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
434						struct zone *zone)
435{
436	int order;
437
438	seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
439	for (order = 0; order < MAX_ORDER; ++order)
440		seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
441	seq_putc(m, '\n');
442}
443
444/*
445 * This walks the free areas for each zone.
446 */
447static int frag_show(struct seq_file *m, void *arg)
448{
449	pg_data_t *pgdat = (pg_data_t *)arg;
450	walk_zones_in_node(m, pgdat, frag_show_print);
451	return 0;
452}
453
454static void pagetypeinfo_showfree_print(struct seq_file *m,
455					pg_data_t *pgdat, struct zone *zone)
456{
457	int order, mtype;
458
459	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
460		seq_printf(m, "Node %4d, zone %8s, type %12s ",
461					pgdat->node_id,
462					zone->name,
463					migratetype_names[mtype]);
464		for (order = 0; order < MAX_ORDER; ++order) {
465			unsigned long freecount = 0;
466			struct free_area *area;
467			struct list_head *curr;
468
469			area = &(zone->free_area[order]);
470
471			list_for_each(curr, &area->free_list[mtype])
472				freecount++;
473			seq_printf(m, "%6lu ", freecount);
474		}
475		seq_putc(m, '\n');
476	}
477}
478
479/* Print out the free pages at each order for each migatetype */
480static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
481{
482	int order;
483	pg_data_t *pgdat = (pg_data_t *)arg;
484
485	/* Print header */
486	seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
487	for (order = 0; order < MAX_ORDER; ++order)
488		seq_printf(m, "%6d ", order);
489	seq_putc(m, '\n');
490
491	walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
492
493	return 0;
494}
495
496static void pagetypeinfo_showblockcount_print(struct seq_file *m,
497					pg_data_t *pgdat, struct zone *zone)
498{
499	int mtype;
500	unsigned long pfn;
501	unsigned long start_pfn = zone->zone_start_pfn;
502	unsigned long end_pfn = start_pfn + zone->spanned_pages;
503	unsigned long count[MIGRATE_TYPES] = { 0, };
504
505	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
506		struct page *page;
507
508		if (!pfn_valid(pfn))
509			continue;
510
511		page = pfn_to_page(pfn);
512
513		/* Watch for unexpected holes punched in the memmap */
514		if (!memmap_valid_within(pfn, page, zone))
515			continue;
516
517		mtype = get_pageblock_migratetype(page);
518
519		if (mtype < MIGRATE_TYPES)
520			count[mtype]++;
521	}
522
523	/* Print counts */
524	seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
525	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
526		seq_printf(m, "%12lu ", count[mtype]);
527	seq_putc(m, '\n');
528}
529
530/* Print out the free pages at each order for each migratetype */
531static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
532{
533	int mtype;
534	pg_data_t *pgdat = (pg_data_t *)arg;
535
536	seq_printf(m, "\n%-23s", "Number of blocks type ");
537	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
538		seq_printf(m, "%12s ", migratetype_names[mtype]);
539	seq_putc(m, '\n');
540	walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
541
542	return 0;
543}
544
545/*
546 * This prints out statistics in relation to grouping pages by mobility.
547 * It is expensive to collect so do not constantly read the file.
548 */
549static int pagetypeinfo_show(struct seq_file *m, void *arg)
550{
551	pg_data_t *pgdat = (pg_data_t *)arg;
552
553	/* check memoryless node */
554	if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
555		return 0;
556
557	seq_printf(m, "Page block order: %d\n", pageblock_order);
558	seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
559	seq_putc(m, '\n');
560	pagetypeinfo_showfree(m, pgdat);
561	pagetypeinfo_showblockcount(m, pgdat);
562
563	return 0;
564}
565
566static const struct seq_operations fragmentation_op = {
567	.start	= frag_start,
568	.next	= frag_next,
569	.stop	= frag_stop,
570	.show	= frag_show,
571};
572
573static int fragmentation_open(struct inode *inode, struct file *file)
574{
575	return seq_open(file, &fragmentation_op);
576}
577
578static const struct file_operations fragmentation_file_operations = {
579	.open		= fragmentation_open,
580	.read		= seq_read,
581	.llseek		= seq_lseek,
582	.release	= seq_release,
583};
584
585static const struct seq_operations pagetypeinfo_op = {
586	.start	= frag_start,
587	.next	= frag_next,
588	.stop	= frag_stop,
589	.show	= pagetypeinfo_show,
590};
591
592static int pagetypeinfo_open(struct inode *inode, struct file *file)
593{
594	return seq_open(file, &pagetypeinfo_op);
595}
596
597static const struct file_operations pagetypeinfo_file_ops = {
598	.open		= pagetypeinfo_open,
599	.read		= seq_read,
600	.llseek		= seq_lseek,
601	.release	= seq_release,
602};
603
604#ifdef CONFIG_ZONE_DMA
605#define TEXT_FOR_DMA(xx) xx "_dma",
606#else
607#define TEXT_FOR_DMA(xx)
608#endif
609
610#ifdef CONFIG_ZONE_DMA32
611#define TEXT_FOR_DMA32(xx) xx "_dma32",
612#else
613#define TEXT_FOR_DMA32(xx)
614#endif
615
616#ifdef CONFIG_HIGHMEM
617#define TEXT_FOR_HIGHMEM(xx) xx "_high",
618#else
619#define TEXT_FOR_HIGHMEM(xx)
620#endif
621
622#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
623					TEXT_FOR_HIGHMEM(xx) xx "_movable",
624
625static const char * const vmstat_text[] = {
626	/* Zoned VM counters */
627	"nr_free_pages",
628	"nr_inactive_anon",
629	"nr_active_anon",
630	"nr_inactive_file",
631	"nr_active_file",
632#ifdef CONFIG_UNEVICTABLE_LRU
633	"nr_unevictable",
634	"nr_mlock",
635#endif
636	"nr_anon_pages",
637	"nr_mapped",
638	"nr_file_pages",
639	"nr_dirty",
640	"nr_writeback",
641	"nr_slab_reclaimable",
642	"nr_slab_unreclaimable",
643	"nr_page_table_pages",
644	"nr_unstable",
645	"nr_bounce",
646	"nr_vmscan_write",
647	"nr_writeback_temp",
648
649#ifdef CONFIG_NUMA
650	"numa_hit",
651	"numa_miss",
652	"numa_foreign",
653	"numa_interleave",
654	"numa_local",
655	"numa_other",
656#endif
657
658#ifdef CONFIG_VM_EVENT_COUNTERS
659	"pgpgin",
660	"pgpgout",
661	"pswpin",
662	"pswpout",
663
664	TEXTS_FOR_ZONES("pgalloc")
665
666	"pgfree",
667	"pgactivate",
668	"pgdeactivate",
669
670	"pgfault",
671	"pgmajfault",
672
673	TEXTS_FOR_ZONES("pgrefill")
674	TEXTS_FOR_ZONES("pgsteal")
675	TEXTS_FOR_ZONES("pgscan_kswapd")
676	TEXTS_FOR_ZONES("pgscan_direct")
677
678	"pginodesteal",
679	"slabs_scanned",
680	"kswapd_steal",
681	"kswapd_inodesteal",
682	"pageoutrun",
683	"allocstall",
684
685	"pgrotated",
686#ifdef CONFIG_HUGETLB_PAGE
687	"htlb_buddy_alloc_success",
688	"htlb_buddy_alloc_fail",
689#endif
690#ifdef CONFIG_UNEVICTABLE_LRU
691	"unevictable_pgs_culled",
692	"unevictable_pgs_scanned",
693	"unevictable_pgs_rescued",
694	"unevictable_pgs_mlocked",
695	"unevictable_pgs_munlocked",
696	"unevictable_pgs_cleared",
697	"unevictable_pgs_stranded",
698	"unevictable_pgs_mlockfreed",
699#endif
700#endif
701};
702
703static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
704							struct zone *zone)
705{
706	int i;
707	seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
708	seq_printf(m,
709		   "\n  pages free     %lu"
710		   "\n        min      %lu"
711		   "\n        low      %lu"
712		   "\n        high     %lu"
713		   "\n        scanned  %lu"
714		   "\n        spanned  %lu"
715		   "\n        present  %lu",
716		   zone_page_state(zone, NR_FREE_PAGES),
717		   min_wmark_pages(zone),
718		   low_wmark_pages(zone),
719		   high_wmark_pages(zone),
720		   zone->pages_scanned,
721		   zone->spanned_pages,
722		   zone->present_pages);
723
724	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
725		seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
726				zone_page_state(zone, i));
727
728	seq_printf(m,
729		   "\n        protection: (%lu",
730		   zone->lowmem_reserve[0]);
731	for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
732		seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
733	seq_printf(m,
734		   ")"
735		   "\n  pagesets");
736	for_each_online_cpu(i) {
737		struct per_cpu_pageset *pageset;
738
739		pageset = zone_pcp(zone, i);
740		seq_printf(m,
741			   "\n    cpu: %i"
742			   "\n              count: %i"
743			   "\n              high:  %i"
744			   "\n              batch: %i",
745			   i,
746			   pageset->pcp.count,
747			   pageset->pcp.high,
748			   pageset->pcp.batch);
749#ifdef CONFIG_SMP
750		seq_printf(m, "\n  vm stats threshold: %d",
751				pageset->stat_threshold);
752#endif
753	}
754	seq_printf(m,
755		   "\n  all_unreclaimable: %u"
756		   "\n  prev_priority:     %i"
757		   "\n  start_pfn:         %lu"
758		   "\n  inactive_ratio:    %u",
759			   zone_is_all_unreclaimable(zone),
760		   zone->prev_priority,
761		   zone->zone_start_pfn,
762		   zone->inactive_ratio);
763	seq_putc(m, '\n');
764}
765
766/*
767 * Output information about zones in @pgdat.
768 */
769static int zoneinfo_show(struct seq_file *m, void *arg)
770{
771	pg_data_t *pgdat = (pg_data_t *)arg;
772	walk_zones_in_node(m, pgdat, zoneinfo_show_print);
773	return 0;
774}
775
776static const struct seq_operations zoneinfo_op = {
777	.start	= frag_start, /* iterate over all zones. The same as in
778			       * fragmentation. */
779	.next	= frag_next,
780	.stop	= frag_stop,
781	.show	= zoneinfo_show,
782};
783
784static int zoneinfo_open(struct inode *inode, struct file *file)
785{
786	return seq_open(file, &zoneinfo_op);
787}
788
789static const struct file_operations proc_zoneinfo_file_operations = {
790	.open		= zoneinfo_open,
791	.read		= seq_read,
792	.llseek		= seq_lseek,
793	.release	= seq_release,
794};
795
796static void *vmstat_start(struct seq_file *m, loff_t *pos)
797{
798	unsigned long *v;
799#ifdef CONFIG_VM_EVENT_COUNTERS
800	unsigned long *e;
801#endif
802	int i;
803
804	if (*pos >= ARRAY_SIZE(vmstat_text))
805		return NULL;
806
807#ifdef CONFIG_VM_EVENT_COUNTERS
808	v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
809			+ sizeof(struct vm_event_state), GFP_KERNEL);
810#else
811	v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
812			GFP_KERNEL);
813#endif
814	m->private = v;
815	if (!v)
816		return ERR_PTR(-ENOMEM);
817	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
818		v[i] = global_page_state(i);
819#ifdef CONFIG_VM_EVENT_COUNTERS
820	e = v + NR_VM_ZONE_STAT_ITEMS;
821	all_vm_events(e);
822	e[PGPGIN] /= 2;		/* sectors -> kbytes */
823	e[PGPGOUT] /= 2;
824#endif
825	return v + *pos;
826}
827
828static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
829{
830	(*pos)++;
831	if (*pos >= ARRAY_SIZE(vmstat_text))
832		return NULL;
833	return (unsigned long *)m->private + *pos;
834}
835
836static int vmstat_show(struct seq_file *m, void *arg)
837{
838	unsigned long *l = arg;
839	unsigned long off = l - (unsigned long *)m->private;
840
841	seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
842	return 0;
843}
844
845static void vmstat_stop(struct seq_file *m, void *arg)
846{
847	kfree(m->private);
848	m->private = NULL;
849}
850
851static const struct seq_operations vmstat_op = {
852	.start	= vmstat_start,
853	.next	= vmstat_next,
854	.stop	= vmstat_stop,
855	.show	= vmstat_show,
856};
857
858static int vmstat_open(struct inode *inode, struct file *file)
859{
860	return seq_open(file, &vmstat_op);
861}
862
863static const struct file_operations proc_vmstat_file_operations = {
864	.open		= vmstat_open,
865	.read		= seq_read,
866	.llseek		= seq_lseek,
867	.release	= seq_release,
868};
869#endif /* CONFIG_PROC_FS */
870
871#ifdef CONFIG_SMP
872static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
873int sysctl_stat_interval __read_mostly = HZ;
874
875static void vmstat_update(struct work_struct *w)
876{
877	refresh_cpu_vm_stats(smp_processor_id());
878	schedule_delayed_work(&__get_cpu_var(vmstat_work),
879		round_jiffies_relative(sysctl_stat_interval));
880}
881
882static void __cpuinit start_cpu_timer(int cpu)
883{
884	struct delayed_work *vmstat_work = &per_cpu(vmstat_work, cpu);
885
886	INIT_DELAYED_WORK_DEFERRABLE(vmstat_work, vmstat_update);
887	schedule_delayed_work_on(cpu, vmstat_work,
888				 __round_jiffies_relative(HZ, cpu));
889}
890
891/*
892 * Use the cpu notifier to insure that the thresholds are recalculated
893 * when necessary.
894 */
895static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
896		unsigned long action,
897		void *hcpu)
898{
899	long cpu = (long)hcpu;
900
901	switch (action) {
902	case CPU_ONLINE:
903	case CPU_ONLINE_FROZEN:
904		start_cpu_timer(cpu);
905		break;
906	case CPU_DOWN_PREPARE:
907	case CPU_DOWN_PREPARE_FROZEN:
908		cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
909		per_cpu(vmstat_work, cpu).work.func = NULL;
910		break;
911	case CPU_DOWN_FAILED:
912	case CPU_DOWN_FAILED_FROZEN:
913		start_cpu_timer(cpu);
914		break;
915	case CPU_DEAD:
916	case CPU_DEAD_FROZEN:
917		refresh_zone_stat_thresholds();
918		break;
919	default:
920		break;
921	}
922	return NOTIFY_OK;
923}
924
925static struct notifier_block __cpuinitdata vmstat_notifier =
926	{ &vmstat_cpuup_callback, NULL, 0 };
927#endif
928
929static int __init setup_vmstat(void)
930{
931#ifdef CONFIG_SMP
932	int cpu;
933
934	refresh_zone_stat_thresholds();
935	register_cpu_notifier(&vmstat_notifier);
936
937	for_each_online_cpu(cpu)
938		start_cpu_timer(cpu);
939#endif
940#ifdef CONFIG_PROC_FS
941	proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
942	proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
943	proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
944	proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
945#endif
946	return 0;
947}
948module_init(setup_vmstat)
949