blob: 292a35fe56c93e91345ad64c54e724c44719f4fc [file] [log] [blame]
/*
* linux/mm/vmstat.c
*
* Manages VM statistics
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* zoned VM statistics
* Copyright (C) 2006 Silicon Graphics, Inc.,
* Christoph Lameter <christoph@lameter.com>
*/
#include <linux/config.h>
#include <linux/mm.h>
#include <linux/module.h>
/*
* Accumulate the page_state information across all CPUs.
* The result is unavoidably approximate - it can change
* during and after execution of this function.
*/
DEFINE_PER_CPU(struct page_state, page_states) = {0};
static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
{
unsigned cpu;
memset(ret, 0, nr * sizeof(unsigned long));
cpus_and(*cpumask, *cpumask, cpu_online_map);
for_each_cpu_mask(cpu, *cpumask) {
unsigned long *in;
unsigned long *out;
unsigned off;
unsigned next_cpu;
in = (unsigned long *)&per_cpu(page_states, cpu);
next_cpu = next_cpu(cpu, *cpumask);
if (likely(next_cpu < NR_CPUS))
prefetch(&per_cpu(page_states, next_cpu));
out = (unsigned long *)ret;
for (off = 0; off < nr; off++)
*out++ += *in++;
}
}
void get_page_state_node(struct page_state *ret, int node)
{
int nr;
cpumask_t mask = node_to_cpumask(node);
nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
nr /= sizeof(unsigned long);
__get_page_state(ret, nr+1, &mask);
}
void get_page_state(struct page_state *ret)
{
int nr;
cpumask_t mask = CPU_MASK_ALL;
nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
nr /= sizeof(unsigned long);
__get_page_state(ret, nr + 1, &mask);
}
void get_full_page_state(struct page_state *ret)
{
cpumask_t mask = CPU_MASK_ALL;
__get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
}
unsigned long read_page_state_offset(unsigned long offset)
{
unsigned long ret = 0;
int cpu;
for_each_online_cpu(cpu) {
unsigned long in;
in = (unsigned long)&per_cpu(page_states, cpu) + offset;
ret += *((unsigned long *)in);
}
return ret;
}
void __mod_page_state_offset(unsigned long offset, unsigned long delta)
{
void *ptr;
ptr = &__get_cpu_var(page_states);
*(unsigned long *)(ptr + offset) += delta;
}
EXPORT_SYMBOL(__mod_page_state_offset);
void mod_page_state_offset(unsigned long offset, unsigned long delta)
{
unsigned long flags;
void *ptr;
local_irq_save(flags);
ptr = &__get_cpu_var(page_states);
*(unsigned long *)(ptr + offset) += delta;
local_irq_restore(flags);
}
EXPORT_SYMBOL(mod_page_state_offset);
void __get_zone_counts(unsigned long *active, unsigned long *inactive,
unsigned long *free, struct pglist_data *pgdat)
{
struct zone *zones = pgdat->node_zones;
int i;
*active = 0;
*inactive = 0;
*free = 0;
for (i = 0; i < MAX_NR_ZONES; i++) {
*active += zones[i].nr_active;
*inactive += zones[i].nr_inactive;
*free += zones[i].free_pages;
}
}
void get_zone_counts(unsigned long *active,
unsigned long *inactive, unsigned long *free)
{
struct pglist_data *pgdat;
*active = 0;
*inactive = 0;
*free = 0;
for_each_online_pgdat(pgdat) {
unsigned long l, m, n;
__get_zone_counts(&l, &m, &n, pgdat);
*active += l;
*inactive += m;
*free += n;
}
}
/*
* Manage combined zone based / global counters
*
* vm_stat contains the global counters
*/
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
EXPORT_SYMBOL(vm_stat);
#ifdef CONFIG_SMP
#define STAT_THRESHOLD 32
/*
* Determine pointer to currently valid differential byte given a zone and
* the item number.
*
* Preemption must be off
*/
static inline s8 *diff_pointer(struct zone *zone, enum zone_stat_item item)
{
return &zone_pcp(zone, smp_processor_id())->vm_stat_diff[item];
}
/*
* For use when we know that interrupts are disabled.
*/
void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
int delta)
{
s8 *p;
long x;
p = diff_pointer(zone, item);
x = delta + *p;
if (unlikely(x > STAT_THRESHOLD || x < -STAT_THRESHOLD)) {
zone_page_state_add(x, zone, item);
x = 0;
}
*p = x;
}
EXPORT_SYMBOL(__mod_zone_page_state);
/*
* For an unknown interrupt state
*/
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
int delta)
{
unsigned long flags;
local_irq_save(flags);
__mod_zone_page_state(zone, item, delta);
local_irq_restore(flags);
}
EXPORT_SYMBOL(mod_zone_page_state);
/*
* Optimized increment and decrement functions.
*
* These are only for a single page and therefore can take a struct page *
* argument instead of struct zone *. This allows the inclusion of the code
* generated for page_zone(page) into the optimized functions.
*
* No overflow check is necessary and therefore the differential can be
* incremented or decremented in place which may allow the compilers to
* generate better code.
*
* The increment or decrement is known and therefore one boundary check can
* be omitted.
*
* Some processors have inc/dec instructions that are atomic vs an interrupt.
* However, the code must first determine the differential location in a zone
* based on the processor number and then inc/dec the counter. There is no
* guarantee without disabling preemption that the processor will not change
* in between and therefore the atomicity vs. interrupt cannot be exploited
* in a useful way here.
*/
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
struct zone *zone = page_zone(page);
s8 *p = diff_pointer(zone, item);
(*p)++;
if (unlikely(*p > STAT_THRESHOLD)) {
zone_page_state_add(*p, zone, item);
*p = 0;
}
}
EXPORT_SYMBOL(__inc_zone_page_state);
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
struct zone *zone = page_zone(page);
s8 *p = diff_pointer(zone, item);
(*p)--;
if (unlikely(*p < -STAT_THRESHOLD)) {
zone_page_state_add(*p, zone, item);
*p = 0;
}
}
EXPORT_SYMBOL(__dec_zone_page_state);
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
unsigned long flags;
struct zone *zone;
s8 *p;
zone = page_zone(page);
local_irq_save(flags);
p = diff_pointer(zone, item);
(*p)++;
if (unlikely(*p > STAT_THRESHOLD)) {
zone_page_state_add(*p, zone, item);
*p = 0;
}
local_irq_restore(flags);
}
EXPORT_SYMBOL(inc_zone_page_state);
void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
unsigned long flags;
struct zone *zone;
s8 *p;
zone = page_zone(page);
local_irq_save(flags);
p = diff_pointer(zone, item);
(*p)--;
if (unlikely(*p < -STAT_THRESHOLD)) {
zone_page_state_add(*p, zone, item);
*p = 0;
}
local_irq_restore(flags);
}
EXPORT_SYMBOL(dec_zone_page_state);
/*
* Update the zone counters for one cpu.
*/
void refresh_cpu_vm_stats(int cpu)
{
struct zone *zone;
int i;
unsigned long flags;
for_each_zone(zone) {
struct per_cpu_pageset *pcp;
pcp = zone_pcp(zone, cpu);
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
if (pcp->vm_stat_diff[i]) {
local_irq_save(flags);
zone_page_state_add(pcp->vm_stat_diff[i],
zone, i);
pcp->vm_stat_diff[i] = 0;
local_irq_restore(flags);
}
}
}
static void __refresh_cpu_vm_stats(void *dummy)
{
refresh_cpu_vm_stats(smp_processor_id());
}
/*
* Consolidate all counters.
*
* Note that the result is less inaccurate but still inaccurate
* if concurrent processes are allowed to run.
*/
void refresh_vm_stats(void)
{
on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
}
EXPORT_SYMBOL(refresh_vm_stats);
#endif
#ifdef CONFIG_PROC_FS
#include <linux/seq_file.h>
static void *frag_start(struct seq_file *m, loff_t *pos)
{
pg_data_t *pgdat;
loff_t node = *pos;
for (pgdat = first_online_pgdat();
pgdat && node;
pgdat = next_online_pgdat(pgdat))
--node;
return pgdat;
}
static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
{
pg_data_t *pgdat = (pg_data_t *)arg;
(*pos)++;
return next_online_pgdat(pgdat);
}
static void frag_stop(struct seq_file *m, void *arg)
{
}
/*
* This walks the free areas for each zone.
*/
static int frag_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
struct zone *zone;
struct zone *node_zones = pgdat->node_zones;
unsigned long flags;
int order;
for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
if (!populated_zone(zone))
continue;
spin_lock_irqsave(&zone->lock, flags);
seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
for (order = 0; order < MAX_ORDER; ++order)
seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
spin_unlock_irqrestore(&zone->lock, flags);
seq_putc(m, '\n');
}
return 0;
}
struct seq_operations fragmentation_op = {
.start = frag_start,
.next = frag_next,
.stop = frag_stop,
.show = frag_show,
};
static char *vmstat_text[] = {
/* Zoned VM counters */
"nr_anon_pages",
"nr_mapped",
"nr_file_pages",
"nr_slab",
"nr_page_table_pages",
/* Page state */
"nr_dirty",
"nr_writeback",
"nr_unstable",
"pgpgin",
"pgpgout",
"pswpin",
"pswpout",
"pgalloc_high",
"pgalloc_normal",
"pgalloc_dma32",
"pgalloc_dma",
"pgfree",
"pgactivate",
"pgdeactivate",
"pgfault",
"pgmajfault",
"pgrefill_high",
"pgrefill_normal",
"pgrefill_dma32",
"pgrefill_dma",
"pgsteal_high",
"pgsteal_normal",
"pgsteal_dma32",
"pgsteal_dma",
"pgscan_kswapd_high",
"pgscan_kswapd_normal",
"pgscan_kswapd_dma32",
"pgscan_kswapd_dma",
"pgscan_direct_high",
"pgscan_direct_normal",
"pgscan_direct_dma32",
"pgscan_direct_dma",
"pginodesteal",
"slabs_scanned",
"kswapd_steal",
"kswapd_inodesteal",
"pageoutrun",
"allocstall",
"pgrotated",
"nr_bounce",
};
/*
* Output information about zones in @pgdat.
*/
static int zoneinfo_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = arg;
struct zone *zone;
struct zone *node_zones = pgdat->node_zones;
unsigned long flags;
for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
int i;
if (!populated_zone(zone))
continue;
spin_lock_irqsave(&zone->lock, flags);
seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
seq_printf(m,
"\n pages free %lu"
"\n min %lu"
"\n low %lu"
"\n high %lu"
"\n active %lu"
"\n inactive %lu"
"\n scanned %lu (a: %lu i: %lu)"
"\n spanned %lu"
"\n present %lu",
zone->free_pages,
zone->pages_min,
zone->pages_low,
zone->pages_high,
zone->nr_active,
zone->nr_inactive,
zone->pages_scanned,
zone->nr_scan_active, zone->nr_scan_inactive,
zone->spanned_pages,
zone->present_pages);
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
seq_printf(m, "\n %-12s %lu", vmstat_text[i],
zone_page_state(zone, i));
seq_printf(m,
"\n protection: (%lu",
zone->lowmem_reserve[0]);
for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
seq_printf(m,
")"
"\n pagesets");
for_each_online_cpu(i) {
struct per_cpu_pageset *pageset;
int j;
pageset = zone_pcp(zone, i);
for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
if (pageset->pcp[j].count)
break;
}
if (j == ARRAY_SIZE(pageset->pcp))
continue;
for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
seq_printf(m,
"\n cpu: %i pcp: %i"
"\n count: %i"
"\n high: %i"
"\n batch: %i",
i, j,
pageset->pcp[j].count,
pageset->pcp[j].high,
pageset->pcp[j].batch);
}
#ifdef CONFIG_NUMA
seq_printf(m,
"\n numa_hit: %lu"
"\n numa_miss: %lu"
"\n numa_foreign: %lu"
"\n interleave_hit: %lu"
"\n local_node: %lu"
"\n other_node: %lu",
pageset->numa_hit,
pageset->numa_miss,
pageset->numa_foreign,
pageset->interleave_hit,
pageset->local_node,
pageset->other_node);
#endif
}
seq_printf(m,
"\n all_unreclaimable: %u"
"\n prev_priority: %i"
"\n temp_priority: %i"
"\n start_pfn: %lu",
zone->all_unreclaimable,
zone->prev_priority,
zone->temp_priority,
zone->zone_start_pfn);
spin_unlock_irqrestore(&zone->lock, flags);
seq_putc(m, '\n');
}
return 0;
}
struct seq_operations zoneinfo_op = {
.start = frag_start, /* iterate over all zones. The same as in
* fragmentation. */
.next = frag_next,
.stop = frag_stop,
.show = zoneinfo_show,
};
static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
unsigned long *v;
struct page_state *ps;
int i;
if (*pos >= ARRAY_SIZE(vmstat_text))
return NULL;
v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
+ sizeof(*ps), GFP_KERNEL);
m->private = v;
if (!v)
return ERR_PTR(-ENOMEM);
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
v[i] = global_page_state(i);
ps = (struct page_state *)(v + NR_VM_ZONE_STAT_ITEMS);
get_full_page_state(ps);
ps->pgpgin /= 2; /* sectors -> kbytes */
ps->pgpgout /= 2;
return v + *pos;
}
static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
{
(*pos)++;
if (*pos >= ARRAY_SIZE(vmstat_text))
return NULL;
return (unsigned long *)m->private + *pos;
}
static int vmstat_show(struct seq_file *m, void *arg)
{
unsigned long *l = arg;
unsigned long off = l - (unsigned long *)m->private;
seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
return 0;
}
static void vmstat_stop(struct seq_file *m, void *arg)
{
kfree(m->private);
m->private = NULL;
}
struct seq_operations vmstat_op = {
.start = vmstat_start,
.next = vmstat_next,
.stop = vmstat_stop,
.show = vmstat_show,
};
#endif /* CONFIG_PROC_FS */