4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
12 #include <linux/config.h>
14 #include <linux/module.h>
17 * Accumulate the page_state information across all CPUs.
18 * The result is unavoidably approximate - it can change
19 * during and after execution of this function.
21 DEFINE_PER_CPU(struct page_state, page_states) = {0};
23 static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
27 memset(ret, 0, nr * sizeof(unsigned long));
28 cpus_and(*cpumask, *cpumask, cpu_online_map);
30 for_each_cpu_mask(cpu, *cpumask) {
36 in = (unsigned long *)&per_cpu(page_states, cpu);
38 next_cpu = next_cpu(cpu, *cpumask);
39 if (likely(next_cpu < NR_CPUS))
40 prefetch(&per_cpu(page_states, next_cpu));
42 out = (unsigned long *)ret;
43 for (off = 0; off < nr; off++)
48 void get_full_page_state(struct page_state *ret)
50 cpumask_t mask = CPU_MASK_ALL;
52 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
55 void __mod_page_state_offset(unsigned long offset, unsigned long delta)
59 ptr = &__get_cpu_var(page_states);
60 *(unsigned long *)(ptr + offset) += delta;
62 EXPORT_SYMBOL(__mod_page_state_offset);
64 void mod_page_state_offset(unsigned long offset, unsigned long delta)
69 local_irq_save(flags);
70 ptr = &__get_cpu_var(page_states);
71 *(unsigned long *)(ptr + offset) += delta;
72 local_irq_restore(flags);
74 EXPORT_SYMBOL(mod_page_state_offset);
76 void __get_zone_counts(unsigned long *active, unsigned long *inactive,
77 unsigned long *free, struct pglist_data *pgdat)
79 struct zone *zones = pgdat->node_zones;
85 for (i = 0; i < MAX_NR_ZONES; i++) {
86 *active += zones[i].nr_active;
87 *inactive += zones[i].nr_inactive;
88 *free += zones[i].free_pages;
92 void get_zone_counts(unsigned long *active,
93 unsigned long *inactive, unsigned long *free)
95 struct pglist_data *pgdat;
100 for_each_online_pgdat(pgdat) {
101 unsigned long l, m, n;
102 __get_zone_counts(&l, &m, &n, pgdat);
110 * Manage combined zone based / global counters
112 * vm_stat contains the global counters
114 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
115 EXPORT_SYMBOL(vm_stat);
119 #define STAT_THRESHOLD 32
122 * Determine pointer to currently valid differential byte given a zone and
125 * Preemption must be off
127 static inline s8 *diff_pointer(struct zone *zone, enum zone_stat_item item)
129 return &zone_pcp(zone, smp_processor_id())->vm_stat_diff[item];
133 * For use when we know that interrupts are disabled.
135 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
141 p = diff_pointer(zone, item);
144 if (unlikely(x > STAT_THRESHOLD || x < -STAT_THRESHOLD)) {
145 zone_page_state_add(x, zone, item);
151 EXPORT_SYMBOL(__mod_zone_page_state);
154 * For an unknown interrupt state
156 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
161 local_irq_save(flags);
162 __mod_zone_page_state(zone, item, delta);
163 local_irq_restore(flags);
165 EXPORT_SYMBOL(mod_zone_page_state);
168 * Optimized increment and decrement functions.
170 * These are only for a single page and therefore can take a struct page *
171 * argument instead of struct zone *. This allows the inclusion of the code
172 * generated for page_zone(page) into the optimized functions.
174 * No overflow check is necessary and therefore the differential can be
175 * incremented or decremented in place which may allow the compilers to
176 * generate better code.
178 * The increment or decrement is known and therefore one boundary check can
181 * Some processors have inc/dec instructions that are atomic vs an interrupt.
182 * However, the code must first determine the differential location in a zone
183 * based on the processor number and then inc/dec the counter. There is no
184 * guarantee without disabling preemption that the processor will not change
185 * in between and therefore the atomicity vs. interrupt cannot be exploited
186 * in a useful way here.
188 static void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
190 s8 *p = diff_pointer(zone, item);
194 if (unlikely(*p > STAT_THRESHOLD)) {
195 zone_page_state_add(*p, zone, item);
200 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
202 __inc_zone_state(page_zone(page), item);
204 EXPORT_SYMBOL(__inc_zone_page_state);
206 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
208 struct zone *zone = page_zone(page);
209 s8 *p = diff_pointer(zone, item);
213 if (unlikely(*p < -STAT_THRESHOLD)) {
214 zone_page_state_add(*p, zone, item);
218 EXPORT_SYMBOL(__dec_zone_page_state);
220 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
224 local_irq_save(flags);
225 __inc_zone_state(zone, item);
226 local_irq_restore(flags);
229 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
234 zone = page_zone(page);
235 local_irq_save(flags);
236 __inc_zone_state(zone, item);
237 local_irq_restore(flags);
239 EXPORT_SYMBOL(inc_zone_page_state);
241 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
247 zone = page_zone(page);
248 local_irq_save(flags);
249 p = diff_pointer(zone, item);
253 if (unlikely(*p < -STAT_THRESHOLD)) {
254 zone_page_state_add(*p, zone, item);
257 local_irq_restore(flags);
259 EXPORT_SYMBOL(dec_zone_page_state);
262 * Update the zone counters for one cpu.
264 void refresh_cpu_vm_stats(int cpu)
270 for_each_zone(zone) {
271 struct per_cpu_pageset *pcp;
273 pcp = zone_pcp(zone, cpu);
275 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
276 if (pcp->vm_stat_diff[i]) {
277 local_irq_save(flags);
278 zone_page_state_add(pcp->vm_stat_diff[i],
280 pcp->vm_stat_diff[i] = 0;
281 local_irq_restore(flags);
286 static void __refresh_cpu_vm_stats(void *dummy)
288 refresh_cpu_vm_stats(smp_processor_id());
292 * Consolidate all counters.
294 * Note that the result is less inaccurate but still inaccurate
295 * if concurrent processes are allowed to run.
297 void refresh_vm_stats(void)
299 on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
301 EXPORT_SYMBOL(refresh_vm_stats);
307 * zonelist = the list of zones passed to the allocator
308 * z = the zone from which the allocation occurred.
310 * Must be called with interrupts disabled.
312 void zone_statistics(struct zonelist *zonelist, struct zone *z)
314 if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {
315 __inc_zone_state(z, NUMA_HIT);
317 __inc_zone_state(z, NUMA_MISS);
318 __inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);
320 if (z->zone_pgdat == NODE_DATA(numa_node_id()))
321 __inc_zone_state(z, NUMA_LOCAL);
323 __inc_zone_state(z, NUMA_OTHER);
327 #ifdef CONFIG_PROC_FS
329 #include <linux/seq_file.h>
331 static void *frag_start(struct seq_file *m, loff_t *pos)
335 for (pgdat = first_online_pgdat();
337 pgdat = next_online_pgdat(pgdat))
343 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
345 pg_data_t *pgdat = (pg_data_t *)arg;
348 return next_online_pgdat(pgdat);
351 static void frag_stop(struct seq_file *m, void *arg)
356 * This walks the free areas for each zone.
358 static int frag_show(struct seq_file *m, void *arg)
360 pg_data_t *pgdat = (pg_data_t *)arg;
362 struct zone *node_zones = pgdat->node_zones;
366 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
367 if (!populated_zone(zone))
370 spin_lock_irqsave(&zone->lock, flags);
371 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
372 for (order = 0; order < MAX_ORDER; ++order)
373 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
374 spin_unlock_irqrestore(&zone->lock, flags);
380 struct seq_operations fragmentation_op = {
387 static char *vmstat_text[] = {
388 /* Zoned VM counters */
393 "nr_page_table_pages",
436 "pgscan_kswapd_high",
437 "pgscan_kswapd_normal",
438 "pgscan_kswapd_dma32",
441 "pgscan_direct_high",
442 "pgscan_direct_normal",
443 "pgscan_direct_dma32",
457 * Output information about zones in @pgdat.
459 static int zoneinfo_show(struct seq_file *m, void *arg)
461 pg_data_t *pgdat = arg;
463 struct zone *node_zones = pgdat->node_zones;
466 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
469 if (!populated_zone(zone))
472 spin_lock_irqsave(&zone->lock, flags);
473 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
481 "\n scanned %lu (a: %lu i: %lu)"
491 zone->nr_scan_active, zone->nr_scan_inactive,
493 zone->present_pages);
495 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
496 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
497 zone_page_state(zone, i));
500 "\n protection: (%lu",
501 zone->lowmem_reserve[0]);
502 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
503 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
507 for_each_online_cpu(i) {
508 struct per_cpu_pageset *pageset;
511 pageset = zone_pcp(zone, i);
512 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
513 if (pageset->pcp[j].count)
516 if (j == ARRAY_SIZE(pageset->pcp))
518 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
525 pageset->pcp[j].count,
526 pageset->pcp[j].high,
527 pageset->pcp[j].batch);
531 "\n all_unreclaimable: %u"
532 "\n prev_priority: %i"
533 "\n temp_priority: %i"
535 zone->all_unreclaimable,
538 zone->zone_start_pfn);
539 spin_unlock_irqrestore(&zone->lock, flags);
545 struct seq_operations zoneinfo_op = {
546 .start = frag_start, /* iterate over all zones. The same as in
550 .show = zoneinfo_show,
553 static void *vmstat_start(struct seq_file *m, loff_t *pos)
556 struct page_state *ps;
559 if (*pos >= ARRAY_SIZE(vmstat_text))
562 v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
563 + sizeof(*ps), GFP_KERNEL);
566 return ERR_PTR(-ENOMEM);
567 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
568 v[i] = global_page_state(i);
569 ps = (struct page_state *)(v + NR_VM_ZONE_STAT_ITEMS);
570 get_full_page_state(ps);
571 ps->pgpgin /= 2; /* sectors -> kbytes */
576 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
579 if (*pos >= ARRAY_SIZE(vmstat_text))
581 return (unsigned long *)m->private + *pos;
584 static int vmstat_show(struct seq_file *m, void *arg)
586 unsigned long *l = arg;
587 unsigned long off = l - (unsigned long *)m->private;
589 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
593 static void vmstat_stop(struct seq_file *m, void *arg)
599 struct seq_operations vmstat_op = {
600 .start = vmstat_start,
606 #endif /* CONFIG_PROC_FS */