blob: a2b6a9f96e5c6390625ec031763a74de9fa5f5b2 [file] [log] [blame]
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001/*
2 * linux/mm/vmstat.c
3 *
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
Christoph Lameter2244b952006-06-30 01:55:33 -07006 *
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
Christoph Lameterf6ac2352006-06-30 01:55:32 -070010 */
11
12#include <linux/config.h>
13#include <linux/mm.h>
Christoph Lameter2244b952006-06-30 01:55:33 -070014#include <linux/module.h>
Christoph Lameterdf9ecab2006-08-31 21:27:35 -070015#include <linux/cpu.h>
Christoph Lameterf6ac2352006-06-30 01:55:32 -070016
Christoph Lameterf6ac2352006-06-30 01:55:32 -070017void __get_zone_counts(unsigned long *active, unsigned long *inactive,
18 unsigned long *free, struct pglist_data *pgdat)
19{
20 struct zone *zones = pgdat->node_zones;
21 int i;
22
23 *active = 0;
24 *inactive = 0;
25 *free = 0;
26 for (i = 0; i < MAX_NR_ZONES; i++) {
27 *active += zones[i].nr_active;
28 *inactive += zones[i].nr_inactive;
29 *free += zones[i].free_pages;
30 }
31}
32
33void get_zone_counts(unsigned long *active,
34 unsigned long *inactive, unsigned long *free)
35{
36 struct pglist_data *pgdat;
37
38 *active = 0;
39 *inactive = 0;
40 *free = 0;
41 for_each_online_pgdat(pgdat) {
42 unsigned long l, m, n;
43 __get_zone_counts(&l, &m, &n, pgdat);
44 *active += l;
45 *inactive += m;
46 *free += n;
47 }
48}
49
Christoph Lameterf8891e52006-06-30 01:55:45 -070050#ifdef CONFIG_VM_EVENT_COUNTERS
51DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
52EXPORT_PER_CPU_SYMBOL(vm_event_states);
53
54static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask)
55{
56 int cpu = 0;
57 int i;
58
59 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
60
61 cpu = first_cpu(*cpumask);
62 while (cpu < NR_CPUS) {
63 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
64
65 cpu = next_cpu(cpu, *cpumask);
66
67 if (cpu < NR_CPUS)
68 prefetch(&per_cpu(vm_event_states, cpu));
69
70
71 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
72 ret[i] += this->event[i];
73 }
74}
75
76/*
77 * Accumulate the vm event counters across all CPUs.
78 * The result is unavoidably approximate - it can change
79 * during and after execution of this function.
80*/
81void all_vm_events(unsigned long *ret)
82{
83 sum_vm_events(ret, &cpu_online_map);
84}
Heiko Carstens32dd66f2006-07-10 04:44:31 -070085EXPORT_SYMBOL_GPL(all_vm_events);
Christoph Lameterf8891e52006-06-30 01:55:45 -070086
87#ifdef CONFIG_HOTPLUG
88/*
89 * Fold the foreign cpu events into our own.
90 *
91 * This is adding to the events on one processor
92 * but keeps the global counts constant.
93 */
94void vm_events_fold_cpu(int cpu)
95{
96 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
97 int i;
98
99 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
100 count_vm_events(i, fold_state->event[i]);
101 fold_state->event[i] = 0;
102 }
103}
104#endif /* CONFIG_HOTPLUG */
105
106#endif /* CONFIG_VM_EVENT_COUNTERS */
107
Christoph Lameter2244b952006-06-30 01:55:33 -0700108/*
109 * Manage combined zone based / global counters
110 *
111 * vm_stat contains the global counters
112 */
113atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
114EXPORT_SYMBOL(vm_stat);
115
116#ifdef CONFIG_SMP
117
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700118static int calculate_threshold(struct zone *zone)
119{
120 int threshold;
121 int mem; /* memory in 128 MB units */
122
123 /*
124 * The threshold scales with the number of processors and the amount
125 * of memory per zone. More memory means that we can defer updates for
126 * longer, more processors could lead to more contention.
127 * fls() is used to have a cheap way of logarithmic scaling.
128 *
129 * Some sample thresholds:
130 *
131 * Threshold Processors (fls) Zonesize fls(mem+1)
132 * ------------------------------------------------------------------
133 * 8 1 1 0.9-1 GB 4
134 * 16 2 2 0.9-1 GB 4
135 * 20 2 2 1-2 GB 5
136 * 24 2 2 2-4 GB 6
137 * 28 2 2 4-8 GB 7
138 * 32 2 2 8-16 GB 8
139 * 4 2 2 <128M 1
140 * 30 4 3 2-4 GB 5
141 * 48 4 3 8-16 GB 8
142 * 32 8 4 1-2 GB 4
143 * 32 8 4 0.9-1GB 4
144 * 10 16 5 <128M 1
145 * 40 16 5 900M 4
146 * 70 64 7 2-4 GB 5
147 * 84 64 7 4-8 GB 6
148 * 108 512 9 4-8 GB 6
149 * 125 1024 10 8-16 GB 8
150 * 125 1024 10 16-32 GB 9
151 */
152
153 mem = zone->present_pages >> (27 - PAGE_SHIFT);
154
155 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
156
157 /*
158 * Maximum threshold is 125
159 */
160 threshold = min(125, threshold);
161
162 return threshold;
163}
Christoph Lameter2244b952006-06-30 01:55:33 -0700164
165/*
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700166 * Refresh the thresholds for each zone.
Christoph Lameter2244b952006-06-30 01:55:33 -0700167 */
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700168static void refresh_zone_stat_thresholds(void)
Christoph Lameter2244b952006-06-30 01:55:33 -0700169{
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700170 struct zone *zone;
171 int cpu;
172 int threshold;
173
174 for_each_zone(zone) {
175
176 if (!zone->present_pages)
177 continue;
178
179 threshold = calculate_threshold(zone);
180
181 for_each_online_cpu(cpu)
182 zone_pcp(zone, cpu)->stat_threshold = threshold;
183 }
Christoph Lameter2244b952006-06-30 01:55:33 -0700184}
185
186/*
187 * For use when we know that interrupts are disabled.
188 */
189void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
190 int delta)
191{
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700192 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
193 s8 *p = pcp->vm_stat_diff + item;
Christoph Lameter2244b952006-06-30 01:55:33 -0700194 long x;
195
Christoph Lameter2244b952006-06-30 01:55:33 -0700196 x = delta + *p;
197
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700198 if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
Christoph Lameter2244b952006-06-30 01:55:33 -0700199 zone_page_state_add(x, zone, item);
200 x = 0;
201 }
Christoph Lameter2244b952006-06-30 01:55:33 -0700202 *p = x;
203}
204EXPORT_SYMBOL(__mod_zone_page_state);
205
206/*
207 * For an unknown interrupt state
208 */
209void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
210 int delta)
211{
212 unsigned long flags;
213
214 local_irq_save(flags);
215 __mod_zone_page_state(zone, item, delta);
216 local_irq_restore(flags);
217}
218EXPORT_SYMBOL(mod_zone_page_state);
219
220/*
221 * Optimized increment and decrement functions.
222 *
223 * These are only for a single page and therefore can take a struct page *
224 * argument instead of struct zone *. This allows the inclusion of the code
225 * generated for page_zone(page) into the optimized functions.
226 *
227 * No overflow check is necessary and therefore the differential can be
228 * incremented or decremented in place which may allow the compilers to
229 * generate better code.
Christoph Lameter2244b952006-06-30 01:55:33 -0700230 * The increment or decrement is known and therefore one boundary check can
231 * be omitted.
232 *
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700233 * NOTE: These functions are very performance sensitive. Change only
234 * with care.
235 *
Christoph Lameter2244b952006-06-30 01:55:33 -0700236 * Some processors have inc/dec instructions that are atomic vs an interrupt.
237 * However, the code must first determine the differential location in a zone
238 * based on the processor number and then inc/dec the counter. There is no
239 * guarantee without disabling preemption that the processor will not change
240 * in between and therefore the atomicity vs. interrupt cannot be exploited
241 * in a useful way here.
242 */
Christoph Lameterca889e62006-06-30 01:55:44 -0700243static void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
Christoph Lameter2244b952006-06-30 01:55:33 -0700244{
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700245 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
246 s8 *p = pcp->vm_stat_diff + item;
Christoph Lameter2244b952006-06-30 01:55:33 -0700247
248 (*p)++;
249
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700250 if (unlikely(*p > pcp->stat_threshold)) {
251 int overstep = pcp->stat_threshold / 2;
252
253 zone_page_state_add(*p + overstep, zone, item);
254 *p = -overstep;
Christoph Lameter2244b952006-06-30 01:55:33 -0700255 }
256}
Christoph Lameterca889e62006-06-30 01:55:44 -0700257
258void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
259{
260 __inc_zone_state(page_zone(page), item);
261}
Christoph Lameter2244b952006-06-30 01:55:33 -0700262EXPORT_SYMBOL(__inc_zone_page_state);
263
264void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
265{
266 struct zone *zone = page_zone(page);
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700267 struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
268 s8 *p = pcp->vm_stat_diff + item;
Christoph Lameter2244b952006-06-30 01:55:33 -0700269
270 (*p)--;
271
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700272 if (unlikely(*p < - pcp->stat_threshold)) {
273 int overstep = pcp->stat_threshold / 2;
274
275 zone_page_state_add(*p - overstep, zone, item);
276 *p = overstep;
Christoph Lameter2244b952006-06-30 01:55:33 -0700277 }
278}
279EXPORT_SYMBOL(__dec_zone_page_state);
280
Christoph Lameterca889e62006-06-30 01:55:44 -0700281void inc_zone_state(struct zone *zone, enum zone_stat_item item)
282{
283 unsigned long flags;
284
285 local_irq_save(flags);
286 __inc_zone_state(zone, item);
287 local_irq_restore(flags);
288}
289
Christoph Lameter2244b952006-06-30 01:55:33 -0700290void inc_zone_page_state(struct page *page, enum zone_stat_item item)
291{
292 unsigned long flags;
293 struct zone *zone;
Christoph Lameter2244b952006-06-30 01:55:33 -0700294
295 zone = page_zone(page);
296 local_irq_save(flags);
Christoph Lameterca889e62006-06-30 01:55:44 -0700297 __inc_zone_state(zone, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700298 local_irq_restore(flags);
299}
300EXPORT_SYMBOL(inc_zone_page_state);
301
302void dec_zone_page_state(struct page *page, enum zone_stat_item item)
303{
304 unsigned long flags;
Christoph Lameter2244b952006-06-30 01:55:33 -0700305
Christoph Lameter2244b952006-06-30 01:55:33 -0700306 local_irq_save(flags);
Christoph Lametera302eb42006-08-31 21:27:34 -0700307 __dec_zone_page_state(page, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700308 local_irq_restore(flags);
309}
310EXPORT_SYMBOL(dec_zone_page_state);
311
312/*
313 * Update the zone counters for one cpu.
314 */
315void refresh_cpu_vm_stats(int cpu)
316{
317 struct zone *zone;
318 int i;
319 unsigned long flags;
320
321 for_each_zone(zone) {
322 struct per_cpu_pageset *pcp;
323
Christoph Lameter39bbcb82006-09-25 23:31:49 -0700324 if (!populated_zone(zone))
325 continue;
326
Christoph Lameter2244b952006-06-30 01:55:33 -0700327 pcp = zone_pcp(zone, cpu);
328
329 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
330 if (pcp->vm_stat_diff[i]) {
331 local_irq_save(flags);
332 zone_page_state_add(pcp->vm_stat_diff[i],
333 zone, i);
334 pcp->vm_stat_diff[i] = 0;
335 local_irq_restore(flags);
336 }
337 }
338}
339
340static void __refresh_cpu_vm_stats(void *dummy)
341{
342 refresh_cpu_vm_stats(smp_processor_id());
343}
344
345/*
346 * Consolidate all counters.
347 *
348 * Note that the result is less inaccurate but still inaccurate
349 * if concurrent processes are allowed to run.
350 */
351void refresh_vm_stats(void)
352{
353 on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
354}
355EXPORT_SYMBOL(refresh_vm_stats);
356
357#endif
358
Christoph Lameterca889e62006-06-30 01:55:44 -0700359#ifdef CONFIG_NUMA
360/*
361 * zonelist = the list of zones passed to the allocator
362 * z = the zone from which the allocation occurred.
363 *
364 * Must be called with interrupts disabled.
365 */
366void zone_statistics(struct zonelist *zonelist, struct zone *z)
367{
368 if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {
369 __inc_zone_state(z, NUMA_HIT);
370 } else {
371 __inc_zone_state(z, NUMA_MISS);
372 __inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);
373 }
Christoph Lameter5d292342006-09-27 01:50:10 -0700374 if (z->node == numa_node_id())
Christoph Lameterca889e62006-06-30 01:55:44 -0700375 __inc_zone_state(z, NUMA_LOCAL);
376 else
377 __inc_zone_state(z, NUMA_OTHER);
378}
379#endif
380
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700381#ifdef CONFIG_PROC_FS
382
383#include <linux/seq_file.h>
384
385static void *frag_start(struct seq_file *m, loff_t *pos)
386{
387 pg_data_t *pgdat;
388 loff_t node = *pos;
389 for (pgdat = first_online_pgdat();
390 pgdat && node;
391 pgdat = next_online_pgdat(pgdat))
392 --node;
393
394 return pgdat;
395}
396
397static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
398{
399 pg_data_t *pgdat = (pg_data_t *)arg;
400
401 (*pos)++;
402 return next_online_pgdat(pgdat);
403}
404
405static void frag_stop(struct seq_file *m, void *arg)
406{
407}
408
409/*
410 * This walks the free areas for each zone.
411 */
412static int frag_show(struct seq_file *m, void *arg)
413{
414 pg_data_t *pgdat = (pg_data_t *)arg;
415 struct zone *zone;
416 struct zone *node_zones = pgdat->node_zones;
417 unsigned long flags;
418 int order;
419
420 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
421 if (!populated_zone(zone))
422 continue;
423
424 spin_lock_irqsave(&zone->lock, flags);
425 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
426 for (order = 0; order < MAX_ORDER; ++order)
427 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
428 spin_unlock_irqrestore(&zone->lock, flags);
429 seq_putc(m, '\n');
430 }
431 return 0;
432}
433
434struct seq_operations fragmentation_op = {
435 .start = frag_start,
436 .next = frag_next,
437 .stop = frag_stop,
438 .show = frag_show,
439};
440
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700441#ifdef CONFIG_ZONE_DMA32
442#define TEXT_FOR_DMA32(xx) xx "_dma32",
443#else
444#define TEXT_FOR_DMA32(xx)
445#endif
446
447#ifdef CONFIG_HIGHMEM
448#define TEXT_FOR_HIGHMEM(xx) xx "_high",
449#else
450#define TEXT_FOR_HIGHMEM(xx)
451#endif
452
453#define TEXTS_FOR_ZONES(xx) xx "_dma", TEXT_FOR_DMA32(xx) xx "_normal", \
454 TEXT_FOR_HIGHMEM(xx)
455
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700456static char *vmstat_text[] = {
Christoph Lameter2244b952006-06-30 01:55:33 -0700457 /* Zoned VM counters */
Christoph Lameterf3dbd342006-06-30 01:55:36 -0700458 "nr_anon_pages",
Christoph Lameter65ba55f2006-06-30 01:55:34 -0700459 "nr_mapped",
Christoph Lameter347ce432006-06-30 01:55:35 -0700460 "nr_file_pages",
Christoph Lameter972d1a72006-09-25 23:31:51 -0700461 "nr_slab_reclaimable",
462 "nr_slab_unreclaimable",
Christoph Lameterdf849a12006-06-30 01:55:38 -0700463 "nr_page_table_pages",
Christoph Lameterb1e7a8f2006-06-30 01:55:39 -0700464 "nr_dirty",
Christoph Lameterce866b32006-06-30 01:55:40 -0700465 "nr_writeback",
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700466 "nr_unstable",
Christoph Lameterd2c5e302006-06-30 01:55:41 -0700467 "nr_bounce",
Andrew Mortone129b5c2006-09-27 01:50:00 -0700468 "nr_vmscan_write",
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700469
Christoph Lameterca889e62006-06-30 01:55:44 -0700470#ifdef CONFIG_NUMA
471 "numa_hit",
472 "numa_miss",
473 "numa_foreign",
474 "numa_interleave",
475 "numa_local",
476 "numa_other",
477#endif
478
Christoph Lameterf8891e52006-06-30 01:55:45 -0700479#ifdef CONFIG_VM_EVENT_COUNTERS
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700480 "pgpgin",
481 "pgpgout",
482 "pswpin",
483 "pswpout",
484
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700485 TEXTS_FOR_ZONES("pgalloc")
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700486
487 "pgfree",
488 "pgactivate",
489 "pgdeactivate",
490
491 "pgfault",
492 "pgmajfault",
493
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700494 TEXTS_FOR_ZONES("pgrefill")
495 TEXTS_FOR_ZONES("pgsteal")
496 TEXTS_FOR_ZONES("pgscan_kswapd")
497 TEXTS_FOR_ZONES("pgscan_direct")
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700498
499 "pginodesteal",
500 "slabs_scanned",
501 "kswapd_steal",
502 "kswapd_inodesteal",
503 "pageoutrun",
504 "allocstall",
505
506 "pgrotated",
Christoph Lameterf8891e52006-06-30 01:55:45 -0700507#endif
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700508};
509
510/*
511 * Output information about zones in @pgdat.
512 */
513static int zoneinfo_show(struct seq_file *m, void *arg)
514{
515 pg_data_t *pgdat = arg;
516 struct zone *zone;
517 struct zone *node_zones = pgdat->node_zones;
518 unsigned long flags;
519
520 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
521 int i;
522
523 if (!populated_zone(zone))
524 continue;
525
526 spin_lock_irqsave(&zone->lock, flags);
527 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
528 seq_printf(m,
529 "\n pages free %lu"
530 "\n min %lu"
531 "\n low %lu"
532 "\n high %lu"
533 "\n active %lu"
534 "\n inactive %lu"
535 "\n scanned %lu (a: %lu i: %lu)"
536 "\n spanned %lu"
537 "\n present %lu",
538 zone->free_pages,
539 zone->pages_min,
540 zone->pages_low,
541 zone->pages_high,
542 zone->nr_active,
543 zone->nr_inactive,
544 zone->pages_scanned,
545 zone->nr_scan_active, zone->nr_scan_inactive,
546 zone->spanned_pages,
547 zone->present_pages);
Christoph Lameter2244b952006-06-30 01:55:33 -0700548
549 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
550 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
551 zone_page_state(zone, i));
552
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700553 seq_printf(m,
554 "\n protection: (%lu",
555 zone->lowmem_reserve[0]);
556 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
557 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
558 seq_printf(m,
559 ")"
560 "\n pagesets");
561 for_each_online_cpu(i) {
562 struct per_cpu_pageset *pageset;
563 int j;
564
565 pageset = zone_pcp(zone, i);
566 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
567 if (pageset->pcp[j].count)
568 break;
569 }
570 if (j == ARRAY_SIZE(pageset->pcp))
571 continue;
572 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
573 seq_printf(m,
574 "\n cpu: %i pcp: %i"
575 "\n count: %i"
576 "\n high: %i"
577 "\n batch: %i",
578 i, j,
579 pageset->pcp[j].count,
580 pageset->pcp[j].high,
581 pageset->pcp[j].batch);
582 }
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700583#ifdef CONFIG_SMP
584 seq_printf(m, "\n vm stats threshold: %d",
585 pageset->stat_threshold);
586#endif
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700587 }
588 seq_printf(m,
589 "\n all_unreclaimable: %u"
590 "\n prev_priority: %i"
591 "\n temp_priority: %i"
592 "\n start_pfn: %lu",
593 zone->all_unreclaimable,
594 zone->prev_priority,
595 zone->temp_priority,
596 zone->zone_start_pfn);
597 spin_unlock_irqrestore(&zone->lock, flags);
598 seq_putc(m, '\n');
599 }
600 return 0;
601}
602
603struct seq_operations zoneinfo_op = {
604 .start = frag_start, /* iterate over all zones. The same as in
605 * fragmentation. */
606 .next = frag_next,
607 .stop = frag_stop,
608 .show = zoneinfo_show,
609};
610
611static void *vmstat_start(struct seq_file *m, loff_t *pos)
612{
Christoph Lameter2244b952006-06-30 01:55:33 -0700613 unsigned long *v;
Christoph Lameterf8891e52006-06-30 01:55:45 -0700614#ifdef CONFIG_VM_EVENT_COUNTERS
615 unsigned long *e;
616#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700617 int i;
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700618
619 if (*pos >= ARRAY_SIZE(vmstat_text))
620 return NULL;
621
Christoph Lameterf8891e52006-06-30 01:55:45 -0700622#ifdef CONFIG_VM_EVENT_COUNTERS
Christoph Lameter2244b952006-06-30 01:55:33 -0700623 v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
Christoph Lameterf8891e52006-06-30 01:55:45 -0700624 + sizeof(struct vm_event_state), GFP_KERNEL);
625#else
626 v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
627 GFP_KERNEL);
628#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700629 m->private = v;
630 if (!v)
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700631 return ERR_PTR(-ENOMEM);
Christoph Lameter2244b952006-06-30 01:55:33 -0700632 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
633 v[i] = global_page_state(i);
Christoph Lameterf8891e52006-06-30 01:55:45 -0700634#ifdef CONFIG_VM_EVENT_COUNTERS
635 e = v + NR_VM_ZONE_STAT_ITEMS;
636 all_vm_events(e);
637 e[PGPGIN] /= 2; /* sectors -> kbytes */
638 e[PGPGOUT] /= 2;
639#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700640 return v + *pos;
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700641}
642
643static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
644{
645 (*pos)++;
646 if (*pos >= ARRAY_SIZE(vmstat_text))
647 return NULL;
648 return (unsigned long *)m->private + *pos;
649}
650
651static int vmstat_show(struct seq_file *m, void *arg)
652{
653 unsigned long *l = arg;
654 unsigned long off = l - (unsigned long *)m->private;
655
656 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
657 return 0;
658}
659
660static void vmstat_stop(struct seq_file *m, void *arg)
661{
662 kfree(m->private);
663 m->private = NULL;
664}
665
666struct seq_operations vmstat_op = {
667 .start = vmstat_start,
668 .next = vmstat_next,
669 .stop = vmstat_stop,
670 .show = vmstat_show,
671};
672
673#endif /* CONFIG_PROC_FS */
674
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700675#ifdef CONFIG_SMP
676/*
677 * Use the cpu notifier to insure that the thresholds are recalculated
678 * when necessary.
679 */
680static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
681 unsigned long action,
682 void *hcpu)
683{
684 switch (action) {
685 case CPU_UP_PREPARE:
686 case CPU_UP_CANCELED:
687 case CPU_DEAD:
688 refresh_zone_stat_thresholds();
689 break;
690 default:
691 break;
692 }
693 return NOTIFY_OK;
694}
695
696static struct notifier_block __cpuinitdata vmstat_notifier =
697 { &vmstat_cpuup_callback, NULL, 0 };
698
699int __init setup_vmstat(void)
700{
701 refresh_zone_stat_thresholds();
702 register_cpu_notifier(&vmstat_notifier);
703 return 0;
704}
705module_init(setup_vmstat)
706#endif