/*
* 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>
* Copyright (C) 2008-2014 Christoph Lameter
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/vmstat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/sched.h>
#include <linux/math64.h>
#include <linux/writeback.h>
#include <linux/compaction.h>
#include <linux/mm_inline.h>
#include <linux/page_ext.h>
#include <linux/page_owner.h>
#include "internal.h"
#ifdef CONFIG_VM_EVENT_COUNTERS
DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
EXPORT_PER_CPU_SYMBOL(vm_event_states);
static void sum_vm_events(unsigned long *ret)
{
int cpu;
int i;
memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
for_each_online_cpu(cpu) {
struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
ret[i] += this->event[i];
}
}
/*
* Accumulate the vm event counters across all CPUs.
* The result is unavoidably approximate - it can change
* during and after execution of this function.
*/
void all_vm_events(unsigned long *ret)
{
get_online_cpus();
sum_vm_events(ret);
put_online_cpus();
}
EXPORT_SYMBOL_GPL(all_vm_events);
/*
* Fold the foreign cpu events into our own.
*
* This is adding to the events on one processor
* but keeps the global counts constant.
*/
void vm_events_fold_cpu(int cpu)
{
struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
int i;
for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
count_vm_events(i, fold_state->event[i]);
fold_state->event[i] = 0;
}
}
#endif /* CONFIG_VM_EVENT_COUNTERS */
/*
* Manage combined zone based / global counters
*
* vm_stat contains the global counters
*/
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
EXPORT_SYMBOL(vm_stat);
#ifdef CONFIG_SMP
int calculate_pressure_threshold(struct zone *zone)
{
int threshold;
int watermark_distance;
/*
* As vmstats are not up to date, there is drift between the estimated
* and real values. For high thresholds and a high number of CPUs, it
* is possible for the min watermark to be breached while the estimated
* value looks fine. The pressure threshold is a reduced value such
* that even the maximum amount of drift will not accidentally breach
* the min watermark
*/
watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
threshold = max(1, (int)(watermark_distance / num_online_cpus()));
/*
* Maximum threshold is 125
*/
threshold = min(125, threshold);
return threshold;
}
int calculate_normal_threshold(struct zone *zone)
{
int threshold;
int mem; /* memory in 128 MB units */
/*
* The threshold scales with the number of processors and the amount
* of memory per zone. More memory means that we can defer updates for
* longer, more processors could lead to more contention.
* fls() is used to have a cheap way of logarithmic scaling.
*
* Some sample thresholds:
*
* Threshold Processors (fls) Zonesize fls(mem+1)
* ------------------------------------------------------------------
* 8 1 1 0.9-1 GB 4
* 16 2 2 0.9-1 GB 4
* 20 2 2 1-2 GB 5
* 24 2 2 2-4 GB 6
* 28 2 2 4-8 GB 7
* 32 2 2 8-16 GB 8
* 4 2 2 <128M 1
* 30 4 3 2-4 GB 5
* 48 4 3 8-16 GB 8
* 32 8 4 1-2 GB 4
* 32 8 4 0.9-1GB 4
* 10 16 5 <128M 1
* 40 16 5 900M 4
* 70 64 7 2-4 GB 5
* 84 64 7 4-8 GB 6
* 108 512 9 4-8 GB 6
* 125 1024 10 8-16 GB 8
* 125 1024 10 16-32 GB 9
*/
mem = zone->managed_pages >> (27 - PAGE_SHIFT);
threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
/*
* Maximum threshold is 125
*/
threshold = min(125, threshold);
return threshold;
}
/*
* Refresh the thresholds for each zone.
*/
void refresh_zone_stat_thresholds(void)
{
struct zone *zone;
int cpu;
int threshold;
for_each_populated_zone(zone) {
unsigned long max_drift, tolerate_drift;
threshold = calculate_normal_threshold(zone);
for_each_online_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
/*
* Only set percpu_drift_mark if there is a danger that
* NR_FREE_PAGES reports the low watermark is ok when in fact
* the min watermark could be breached by an allocation
*/
tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
max_drift = num_online_cpus() * threshold;
if (max_drift > tolerate_drift)
zone->percpu_drift_mark = high_wmark_pages(zone) +
max_drift;
}
}
void set_pgdat_percpu_threshold(pg_data_t *pgdat,
int (*calculate_pressure)(struct zone *))
{
struct zone *zone;
int cpu;
int threshold;
int i;
for (i = 0; i < pgdat->nr_zones; i++) {
zone = &pgdat->node_zones[i];
if (!zone->percpu_drift_mark)
continue;
threshold = (*calculate_pressure)(zone);
for_each_online_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
}
}
/*
* For use when we know that interrupts are disabled,
* or when we know that preemption is disabled and that
* particular counter cannot be updated from interrupt context.
*/
void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
long delta)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
long x;
long t;
x = delta + __this_cpu_read(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(x > t || x < -t)) {
zone_page_state_add(x, zone, item);
x = 0;
}
__this_cpu_write(*p, x);
}
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.
*
* NOTE: These functions are very performance sensitive. Change only
* with care.
*
* 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_state(struct zone *zone, enum zone_stat_item item)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
v = __this_cpu_inc_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v > t)) {
s8 overstep = t >> 1;
zone_page_state_add(v + overstep, zone, item);
__this_cpu_write(*p, -overstep);
}
}
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
__inc_zone_state(page_zone(page), item);
}
EXPORT_SYMBOL(__inc_zone_page_state);
void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
v = __this_cpu_dec_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v < - t)) {
s8 overstep = t >> 1;
zone_page_state_add(v - overstep, zone, item);
__this_cpu_write(*p, overstep);
}
}
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
__dec_zone_state(page_zone(page), item);
}
EXPORT_SYMBOL(__dec_zone_page_state);
#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
/*
* If we have cmpxchg_local support then we do not need to incur the overhead
* that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
*
* mod_state() modifies the zone counter state through atomic per cpu
* operations.
*
* Overstep mode specifies how overstep should handled:
* 0 No overstepping
* 1 Overstepping half of threshold
* -1 Overstepping minus half of threshold
*/
static inline void mod_state(struct zone *zone, enum zone_stat_item item,
long delta, int overstep_mode)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
long o, n, t, z;
do {
z = 0; /* overflow to zone counters */
/*
* The fetching of the stat_threshold is racy. We may apply
* a counter threshold to the wrong the cpu if we get
* rescheduled while executing here. However, the next
* counter update will apply the threshold again and
* therefore bring the counter under the threshold again.
*
* Most of the time the thresholds are the same anyways
* for all cpus in a zone.
*/
t = this_cpu_read(pcp->stat_threshold);
o = this_cpu_read(*p);
n = delta + o;
if (n > t || n < -t) {
int os = overstep_mode * (t >> 1) ;
/* Overflow must be added to zone counters */
z = n + os;
n = -os;
}
} while (this_cpu_cmpxchg(*p, o, n) != o);
if (z)
zone_page_state_add(z, zone, item);
}
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
long delta)
{
mod_state(zone, item, delta, 0);
}
EXPORT_SYMBOL(mod_zone_page_state);
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
mod_state(zone, item, 1, 1);
}
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
mod_state(page_zone(page), item, 1, 1);
}
EXPORT_SYMBOL(inc_zone_page_state);
void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
mod_state(page_zone(page), item, -1, -1);
}
EXPORT_SYMBOL(dec_zone_page_state);
#else
/*
* Use interrupt disable to serialize counter updates
*/
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
long 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);
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
unsigned long flags;
local_irq_save(flags);
__inc_zone_state(zone, item);
local_irq_restore(flags);
}
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
unsigned long flags;
struct zone *zone;
zone = page_zone(page);
local_irq_save(flags);
__inc_zone_state(zone, item);
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;
local_irq_save(flags);
__dec_zone_page_state(page, item);
local_irq_restore(flags);
}
EXPORT_SYMBOL(dec_zone_page_state);
#endif
/*
* Fold a differential into the global counters.
* Returns the number of counters updated.
*/
static int fold_diff(int *diff)
{
int i;
int changes = 0;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
if (diff[i]) {
atomic_long_add(diff[i], &vm_stat[i]);
changes++;
}
return changes;
}
/*
* Update the zone counters for the current cpu.
*
* Note that refresh_cpu_vm_stats strives to only access
* node local memory. The per cpu pagesets on remote zones are placed
* in the memory local to the processor using that pageset. So the
* loop over all zones will access a series of cachelines local to
* the processor.
*
* The call to zone_page_state_add updates the cachelines with the
* statistics in the remote zone struct as well as the global cachelines
* with the global counters. These could cause remote node cache line
* bouncing and will have to be only done when necessary.
*
* The function returns the number of global counters updated.
*/
static int refresh_cpu_vm_stats(void)
{
struct zone *zone;
int i;
int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
int changes = 0;
for_each_populated_zone(zone) {
struct per_cpu_pageset __percpu *p = zone->pageset;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
int v;
v = this_cpu_xchg(p->vm_stat_diff[i], 0);
if (v) {
atomic_long_add(v, &zone->vm_stat[i]);
global_diff[i] += v;
#ifdef CONFIG_NUMA
/* 3 seconds idle till flush */
__this_cpu_write(p->expire, 3);
#endif
}
}
cond_resched();
#ifdef CONFIG_NUMA
/*
* Deal with draining the remote pageset of this
* processor
*
* Check if there are pages remaining in this pageset
* if not then there is nothing to expire.
*/
if (!__this_cpu_read(p->expire) ||
!__this_cpu_read(p->pcp.count))
continue;
/*
* We never drain zones local to this processor.
*/
if (zone_to_nid(zone) == numa_node_id()) {
__this_cpu_write(p->expire, 0);
continue;
}
if (__this_cpu_dec_return(p->expire))
continue;
if (__this_cpu_read(p->pcp.count)) {
drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
changes++;
}
#endif
}
changes += fold_diff(global_diff);
return changes;
}
/*
* Fold the data for an offline cpu into the global array.
* There cannot be any access by the offline cpu and therefore
* synchronization is simplified.
*/
void cpu_vm_stats_fold(int cpu)
{
struct zone *zone;
int i;
int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
for_each_populated_zone(zone) {
struct per_cpu_pageset *p;
p = per_cpu_ptr(zone->pageset, cpu);
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
if (p->vm_stat_diff[i]) {
int v;
v = p->vm_stat_diff[i];
p->vm_stat_diff[i] = 0;
atomic_long_add(v, &zone->vm_stat[i]);
global_diff[i] += v;
}
}
fold_diff(global_diff);
}
/*
* this is only called if !populated_zone(zone), which implies no other users of
* pset->vm_stat_diff[] exsist.
*/
void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
{
int i;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
if (pset->vm_stat_diff[i]) {
int v = pset->vm_stat_diff[i];
pset->vm_stat_diff[i] = 0;
atomic_long_add(v, &zone->vm_stat[i]);
atomic_long_add(v, &vm_stat[i]);
}
}
#endif
#ifdef CONFIG_NUMA
/*
* zonelist = the list of zones passed to the allocator
* z = the zone from which the allocation occurred.
*
* Must be called with interrupts disabled.
*
* When __GFP_OTHER_NODE is set assume the node of the preferred
* zone is the local node. This is useful for daemons who allocate
* memory on behalf of other processes.
*/
void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
{
if (z->zone_pgdat == preferred_zone->zone_pgdat) {
__inc_zone_state(z, NUMA_HIT);
} else {
__inc_zone_state(z, NUMA_MISS);
__inc_zone_state(preferred_zone, NUMA_FOREIGN);
}
if (z->node == ((flags & __GFP_OTHER_NODE) ?
preferred_zone->node : numa_node_id()))
__inc_zone_state(z, NUMA_LOCAL);
else
__inc_zone_state(z, NUMA_OTHER);
}
/*
* Determine the per node value of a stat item.
*/
unsigned long node_page_state(int node, enum zone_stat_item item)
{
struct zone *zones = NODE_DATA(node)->node_zones;
return
#ifdef CONFIG_ZONE_DMA
zone_page_state(&zones[ZONE_DMA], item) +
#endif
#ifdef CONFIG_ZONE_DMA32
zone_page_state(&zones[ZONE_DMA32], item) +
#endif
#ifdef CONFIG_HIGHMEM
zone_page_state(&zones[ZONE_HIGHMEM], item) +
#endif
zone_page_state(&zones[ZONE_NORMAL], item) +
zone_page_state(&zones[ZONE_MOVABLE], item);
}
#endif
#ifdef CONFIG_COMPACTION
struct contig_page_info {
unsigned long free_pages;
unsigned long free_blocks_total;
unsigned long free_blocks_suitable;
};
/*
* Calculate the number of free pages in a zone, how many contiguous
* pages are free and how many are large enough to satisfy an allocation of
* the target size. Note that this function makes no attempt to estimate
* how many suitable free blocks there *might* be if MOVABLE pages were
* migrated. Calculating that is possible, but expensive and can be
* figured out from userspace
*/
static void fill_contig_page_info(struct zone *zone,
unsigned int suitable_order,
struct contig_page_info *info)
{
unsigned int order;
info->free_pages = 0;
info->free_blocks_total = 0;
info->free_blocks_suitable = 0;
for (order = 0; order < MAX_ORDER; order++) {
unsigned long blocks;
/* Count number of free blocks */
blocks = zone->free_area[order].nr_free;
info->free_blocks_total += blocks;
/* Count free base pages */
info->free_pages += blocks << order;
/* Count the suitable free blocks */
if (order >= suitable_order)
info->free_blocks_suitable += blocks <<
(order - suitable_order);
}
}
/*
* A fragmentation index only makes sense if an allocation of a requested
* size would fail. If that is true, the fragmentation index indicates
* whether external fragmentation or a lack of memory was the problem.
* The value can be used to determine if page reclaim or compaction
* should be used
*/
static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
{
unsigned long requested = 1UL << order;
if (!info->free_blocks_total)
return 0;
/* Fragmentation index only makes sense when a request would fail */
if (info->free_blocks_suitable)
return -1000;
/*
* Index is between 0 and 1 so return within 3 decimal places
*
* 0 => allocation would fail due to lack of memory
* 1 => allocation would fail due to fragmentation
*/
return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
}
/* Same as __fragmentation index but allocs contig_page_info on stack */
int fragmentation_index(struct zone *zone, unsigned int order)
{
struct contig_page_info info;
fill_contig_page_info(zone, order, &info);
return __fragmentation_index(order, &info);
}
#endif
#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
#ifdef CONFIG_ZONE_DMA
#define TEXT_FOR_DMA(xx) xx "_dma",
#else
#define TEXT_FOR_DMA(xx)
#endif
#ifdef CONFIG_ZONE_DMA32
#define TEXT_FOR_DMA32(xx) xx "_dma32",
#else
#define TEXT_FOR_DMA32(xx)
#endif
#ifdef CONFIG_HIGHMEM
#define TEXT_FOR_HIGHMEM(xx) xx "_high",
#else
#define TEXT_FOR_HIGHMEM(xx)
#endif
#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
TEXT_FOR_HIGHMEM(xx) xx "_movable",
const char * const vmstat_text[] = {
/* enum zone_stat_item countes */
"nr_free_pages",
"nr_alloc_batch",
"nr_inactive_anon",
"nr_active_anon",
"nr_inactive_file",
"nr_active_file",
"nr_unevictable",
"nr_mlock",
"nr_anon_pages",
"nr_mapped",
"nr_file_pages",
"nr_dirty",
"nr_writeback",
"nr_slab_reclaimable",
"nr_slab_unreclaimable",
"nr_page_table_pages",
"nr_kernel_stack",
"nr_unstable",
"nr_bounce",
"nr_vmscan_write",
"nr_vmscan_immediate_reclaim",
"nr_writeback_temp",
"nr_isolated_anon",
"nr_isolated_file",
"nr_shmem",
"nr_dirtied",
"nr_written",
"nr_pages_scanned",
#ifdef CONFIG_NUMA
"numa_hit",
"numa_miss",
"numa_foreign",
"numa_interleave",
"numa_local",
"numa_other",
#endif
"workingset_refault",
"workingset_activate",
"workingset_nodereclaim",
"nr_anon_transparent_hugepages",
"nr_free_cma",
/* enum writeback_stat_item counters */
"nr_dirty_threshold",
"nr_dirty_background_threshold",
#ifdef CONFIG_VM_EVENT_COUNTERS
/* enum vm_event_item counters */
"pgpgin",
"pgpgout",
"pswpin",
"pswpout",
TEXTS_FOR_ZONES("pgalloc")
"pgfree",
"pgactivate",
"pgdeactivate",
"pgfault",
"pgmajfault",
TEXTS_FOR_ZONES("pgrefill")
TEXTS_FOR_ZONES("pgsteal_kswapd")
TEXTS_FOR_ZONES("pgsteal_direct")
TEXTS_FOR_ZONES("pgscan_kswapd")
TEXTS_FOR_ZONES("pgscan_direct")
"pgscan_direct_throttle",
#ifdef CONFIG_NUMA
"zone_reclaim_failed",
#endif
"pginodesteal",
"slabs_scanned",
"kswapd_inodesteal",
"kswapd_low_wmark_hit_quickly",
"kswapd_high_wmark_hit_quickly",
"pageoutrun",
"allocstall",
"pgrotated",
"drop_pagecache",
"drop_slab",
#ifdef CONFIG_NUMA_BALANCING
"numa_pte_updates",
"numa_huge_pte_updates",
"numa_hint_faults",
"numa_hint_faults_local",
"numa_pages_migrated",
#endif
#ifdef CONFIG_MIGRATION
"pgmigrate_success",
"pgmigrate_fail",
#endif
#ifdef CONFIG_COMPACTION
"compact_migrate_scanned",
"compact_free_scanned",
"compact_isolated",
"compact_stall",
"compact_fail",
"compact_success",
#endif
#ifdef CONFIG_HUGETLB_PAGE
"htlb_buddy_alloc_success",
"htlb_buddy_alloc_fail",
#endif
"unevictable_pgs_culled",
"unevictable_pgs_scanned",
"unevictable_pgs_rescued",
"unevictable_pgs_mlocked",
"unevictable_pgs_munlocked",
"unevictable_pgs_cleared",
"unevictable_pgs_stranded",
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
"thp_fault_alloc",
"thp_fault_fallback",
"thp_collapse_alloc",
"thp_collapse_alloc_failed",
"thp_split",
"thp_zero_page_alloc",
"thp_zero_page_alloc_failed",
#endif
#ifdef CONFIG_MEMORY_BALLOON
"balloon_inflate",
"balloon_deflate",
#ifdef CONFIG_BALLOON_COMPACTION
"balloon_migrate",
#endif
#endif /* CONFIG_MEMORY_BALLOON */
#ifdef CONFIG_DEBUG_TLBFLUSH
#ifdef CONFIG_SMP
"nr_tlb_remote_flush",
"nr_tlb_remote_flush_received",
#endif /* CONFIG_SMP */
"nr_tlb_local_flush_all",
"nr_tlb_local_flush_one",
#endif /* CONFIG_DEBUG_TLBFLUSH */
#ifdef CONFIG_DEBUG_VM_VMACACHE
"vmacache_find_calls",
"vmacache_find_hits",
"vmacache_full_flushes",
#endif
#endif /* CONFIG_VM_EVENTS_COUNTERS */
};
#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
defined(CONFIG_PROC_FS)
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)
{
}
/* Walk all the zones in a node and print using a callback */
static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
{
struct zone *zone;
struct zone *node_zones = pgdat->node_zones;
unsigned long flags;
for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
if (!populated_zone(zone))
continue;
spin_lock_irqsave(&zone->lock, flags);
print(m, pgdat, zone);
spin_unlock_irqrestore(&zone->lock, flags);
}
}
#endif
#ifdef CONFIG_PROC_FS
static char * const migratetype_names[MIGRATE_TYPES] = {
"Unmovable",
"Movable",
"Reclaimable",
"HighAtomic",
#ifdef CONFIG_CMA
"CMA",
#endif
#ifdef CONFIG_MEMORY_ISOLATION
"Isolate",
#endif
};
static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
struct zone *zone)
{
int order;
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);
seq_putc(m, '\n');
}
/*
* 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;
walk_zones_in_node(m, pgdat, frag_show_print);
return 0;
}
static void pagetypeinfo_showfree_print(struct seq_file *m,
pg_data_t *pgdat, struct zone *zone)
{
int order, mtype;
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
seq_printf(m, "Node %4d, zone %8s, type %12s ",
pgdat->node_id,
zone->name,
migratetype_names[mtype]);
for (order = 0; order < MAX_ORDER; ++order) {
unsigned long freecount = 0;
struct free_area *area;
struct list_head *curr;
area = &(zone->free_area[order]);
list_for_each(curr, &area->free_list[mtype])
freecount++;
seq_printf(m, "%6lu ", freecount);
}
seq_putc(m, '\n');
}
}
/* Print out the free pages at each order for each migatetype */
static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
{
int order;
pg_data_t *pgdat = (pg_data_t *)arg;
/* Print header */
seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
for (order = 0; order < MAX_ORDER; ++order)
seq_printf(m, "%6d ", order);
seq_putc(m, '\n');
walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
return 0;
}
static void pagetypeinfo_showblockcount_print(struct seq_file *m,
pg_data_t *pgdat, struct zone *zone)
{
int mtype;
unsigned long pfn;
unsigned long start_pfn = zone->zone_start_pfn;
unsigned long end_pfn = zone_end_pfn(zone);
unsigned long count[MIGRATE_TYPES] = { 0, };
for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
struct page *page;
if (!pfn_valid(pfn))
continue;
page = pfn_to_page(pfn);
/* Watch for unexpected holes punched in the memmap */
if (!memmap_valid_within(pfn, page, zone))
continue;
mtype = get_pageblock_migratetype(page);
if (mtype < MIGRATE_TYPES)
count[mtype]++;
}
/* Print counts */
seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
seq_printf(m, "%12lu ", count[mtype]);
seq_putc(m, '\n');
}
/* Print out the free pages at each order for each migratetype */
static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
{
int mtype;
pg_data_t *pgdat = (pg_data_t *)arg;
seq_printf(m, "\n%-23s", "Number of blocks type ");
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
seq_printf(m, "%12s ", migratetype_names[mtype]);
seq_putc(m, '\n');
walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
return 0;
}
#ifdef CONFIG_PAGE_OWNER
static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
pg_data_t *pgdat,
struct zone *zone)
{
struct page *page;
struct page_ext *page_ext;
unsigned long pfn = zone->zone_start_pfn, block_end_pfn;
unsigned long end_pfn = pfn + zone->spanned_pages;
unsigned long count[MIGRATE_TYPES] = { 0, };
int pageblock_mt, page_mt;
int i;
/* Scan block by block. First and last block may be incomplete */
pfn = zone->zone_start_pfn;
/*
* Walk the zone in pageblock_nr_pages steps. If a page block spans
* a zone boundary, it will be double counted between zones. This does
* not matter as the mixed block count will still be correct
*/
for (; pfn < end_pfn; ) {
if (!pfn_valid(pfn)) {
pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
continue;
}
block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
block_end_pfn = min(block_end_pfn, end_pfn);
page = pfn_to_page(pfn);
pageblock_mt = get_pfnblock_migratetype(page, pfn);
for (; pfn < block_end_pfn; pfn++) {
if (!pfn_valid_within(pfn))
continue;
page = pfn_to_page(pfn);
if (PageBuddy(page)) {
pfn += (1UL << page_order(page)) - 1;
continue;
}
if (PageReserved(page))
continue;
page_ext = lookup_page_ext(page);
if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
continue;
page_mt = gfpflags_to_migratetype(page_ext->gfp_mask);
if (pageblock_mt != page_mt) {
if (is_migrate_cma(pageblock_mt))
count[MIGRATE_MOVABLE]++;
else
count[pageblock_mt]++;
pfn = block_end_pfn;
break;
}
pfn += (1UL << page_ext->order) - 1;
}
}
/* Print counts */
seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
for (i = 0; i < MIGRATE_TYPES; i++)
seq_printf(m, "%12lu ", count[i]);
seq_putc(m, '\n');
}
#endif /* CONFIG_PAGE_OWNER */
/*
* Print out the number of pageblocks for each migratetype that contain pages
* of other types. This gives an indication of how well fallbacks are being
* contained by rmqueue_fallback(). It requires information from PAGE_OWNER
* to determine what is going on
*/
static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
{
#ifdef CONFIG_PAGE_OWNER
int mtype;
if (!page_owner_inited)
return;
drain_all_pages(NULL);
seq_printf(m, "\n%-23s", "Number of mixed blocks ");
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
seq_printf(m, "%12s ", migratetype_names[mtype]);
seq_putc(m, '\n');
walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print);
#endif /* CONFIG_PAGE_OWNER */
}
/*
* This prints out statistics in relation to grouping pages by mobility.
* It is expensive to collect so do not constantly read the file.
*/
static int pagetypeinfo_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
/* check memoryless node */
if (!node_state(pgdat->node_id, N_MEMORY))
return 0;
seq_printf(m, "Page block order: %d\n", pageblock_order);
seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
seq_putc(m, '\n');
pagetypeinfo_showfree(m, pgdat);
pagetypeinfo_showblockcount(m, pgdat);
pagetypeinfo_showmixedcount(m, pgdat);
return 0;
}
static const struct seq_operations fragmentation_op = {
.start = frag_start,
.next = frag_next,
.stop = frag_stop,
.show = frag_show,
};
static int fragmentation_open(struct inode *inode, struct file *file)
{
return seq_open(file, &fragmentation_op);
}
static const struct file_operations fragmentation_file_operations = {
.open = fragmentation_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static const struct seq_operations pagetypeinfo_op = {
.start = frag_start,
.next = frag_next,
.stop = frag_stop,
.show = pagetypeinfo_show,
};
static int pagetypeinfo_open(struct inode *inode, struct file *file)
{
return seq_open(file, &pagetypeinfo_op);
}
static const struct file_operations pagetypeinfo_file_ops = {
.open = pagetypeinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
struct zone *zone)
{
int i;
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 scanned %lu"
"\n spanned %lu"
"\n present %lu"
"\n managed %lu",
zone_page_state(zone, NR_FREE_PAGES),
min_wmark_pages(zone),
low_wmark_pages(zone),
high_wmark_pages(zone),
zone_page_state(zone, NR_PAGES_SCANNED),
zone->spanned_pages,
zone->present_pages,
zone->managed_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: (%ld",
zone->lowmem_reserve[0]);
for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
seq_printf(m,
")"
"\n pagesets");
for_each_online_cpu(i) {
struct per_cpu_pageset *pageset;
pageset = per_cpu_ptr(zone->pageset, i);
seq_printf(m,
"\n cpu: %i"
"\n count: %i"
"\n high: %i"
"\n batch: %i",
i,
pageset->pcp.count,
pageset->pcp.high,
pageset->pcp.batch);
#ifdef CONFIG_SMP
seq_printf(m, "\n vm stats threshold: %d",
pageset->stat_threshold);
#endif
}
seq_printf(m,
"\n all_unreclaimable: %u"
"\n start_pfn: %lu"
"\n inactive_ratio: %u",
!zone_reclaimable(zone),
zone->zone_start_pfn,
zone->inactive_ratio);
seq_putc(m, '\n');
}
/*
* Output information about zones in @pgdat.
*/
static int zoneinfo_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
walk_zones_in_node(m, pgdat, zoneinfo_show_print);
return 0;
}
static const 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 int zoneinfo_open(struct inode *inode, struct file *file)
{
return seq_open(file, &zoneinfo_op);
}
static const struct file_operations proc_zoneinfo_file_operations = {
.open = zoneinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
enum writeback_stat_item {
NR_DIRTY_THRESHOLD,
NR_DIRTY_BG_THRESHOLD,
NR_VM_WRITEBACK_STAT_ITEMS,
};
static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
unsigned long *v;
int i, stat_items_size;
if (*pos >= ARRAY_SIZE(vmstat_text))
return NULL;
stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
#ifdef CONFIG_VM_EVENT_COUNTERS
stat_items_size += sizeof(struct vm_event_state);
#endif
v = kmalloc(stat_items_size, 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);
v += NR_VM_ZONE_STAT_ITEMS;
global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
v + NR_DIRTY_THRESHOLD);
v += NR_VM_WRITEBACK_STAT_ITEMS;
#ifdef CONFIG_VM_EVENT_COUNTERS
all_vm_events(v);
v[PGPGIN] /= 2; /* sectors -> kbytes */
v[PGPGOUT] /= 2;
#endif
return (unsigned long *)m->private + *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;
}
static const struct seq_operations vmstat_op = {
.start = vmstat_start,
.next = vmstat_next,
.stop = vmstat_stop,
.show = vmstat_show,
};
static int vmstat_open(struct inode *inode, struct file *file)
{
return seq_open(file, &vmstat_op);
}
static const struct file_operations proc_vmstat_file_operations = {
.open = vmstat_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SMP
static struct workqueue_struct *vmstat_wq;
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
int sysctl_stat_interval __read_mostly = HZ;
static cpumask_var_t cpu_stat_off;
static void vmstat_update(struct work_struct *w)
{
if (refresh_cpu_vm_stats()) {
/*
* Counters were updated so we expect more updates
* to occur in the future. Keep on running the
* update worker thread.
*/
queue_delayed_work_on(smp_processor_id(), vmstat_wq,
this_cpu_ptr(&vmstat_work),
round_jiffies_relative(sysctl_stat_interval));
} else {
/*
* We did not update any counters so the app may be in
* a mode where it does not cause counter updates.
* We may be uselessly running vmstat_update.
* Defer the checking for differentials to the
* shepherd thread on a different processor.
*/
int r;
/*
* Shepherd work thread does not race since it never
* changes the bit if its zero but the cpu
* online / off line code may race if
* worker threads are still allowed during
* shutdown / startup.
*/
r = cpumask_test_and_set_cpu(smp_processor_id(),
cpu_stat_off);
VM_BUG_ON(r);
}
}
/*
* Check if the diffs for a certain cpu indicate that
* an update is needed.
*/
static bool need_update(int cpu)
{
struct zone *zone;
for_each_populated_zone(zone) {
struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
/*
* The fast way of checking if there are any vmstat diffs.
* This works because the diffs are byte sized items.
*/
if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
return true;
}
return false;
}
/*
* Shepherd worker thread that checks the
* differentials of processors that have their worker
* threads for vm statistics updates disabled because of
* inactivity.
*/
static void vmstat_shepherd(struct work_struct *w);
static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd);
static void vmstat_shepherd(struct work_struct *w)
{
int cpu;
get_online_cpus();
/* Check processors whose vmstat worker threads have been disabled */
for_each_cpu(cpu, cpu_stat_off)
if (need_update(cpu) &&
cpumask_test_and_clear_cpu(cpu, cpu_stat_off))
queue_delayed_work_on(cpu, vmstat_wq,
&per_cpu(vmstat_work, cpu), 0);
put_online_cpus();
schedule_delayed_work(&shepherd,
round_jiffies_relative(sysctl_stat_interval));
}
static void __init start_shepherd_timer(void)
{
int cpu;
for_each_possible_cpu(cpu)
INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu),
vmstat_update);
if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL))
BUG();
cpumask_copy(cpu_stat_off, cpu_online_mask);
vmstat_wq = alloc_workqueue("vmstat", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
schedule_delayed_work(&shepherd,
round_jiffies_relative(sysctl_stat_interval));
}
static void vmstat_cpu_dead(int node)
{
int cpu;
get_online_cpus();
for_each_online_cpu(cpu)
if (cpu_to_node(cpu) == node)
goto end;
node_clear_state(node, N_CPU);
end:
put_online_cpus();
}
/*
* Use the cpu notifier to insure that the thresholds are recalculated
* when necessary.
*/
static int vmstat_cpuup_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
long cpu = (long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
refresh_zone_stat_thresholds();
node_set_state(cpu_to_node(cpu), N_CPU);
cpumask_set_cpu(cpu, cpu_stat_off);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
cpumask_clear_cpu(cpu, cpu_stat_off);
break;
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
cpumask_set_cpu(cpu, cpu_stat_off);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
refresh_zone_stat_thresholds();
vmstat_cpu_dead(cpu_to_node(cpu));
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block vmstat_notifier =
{ &vmstat_cpuup_callback, NULL, 0 };
#endif
static int __init setup_vmstat(void)
{
#ifdef CONFIG_SMP
cpu_notifier_register_begin();
__register_cpu_notifier(&vmstat_notifier);
start_shepherd_timer();
cpu_notifier_register_done();
#endif
#ifdef CONFIG_PROC_FS
proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
#endif
return 0;
}
module_init(setup_vmstat)
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
/*
* Return an index indicating how much of the available free memory is
* unusable for an allocation of the requested size.
*/
static int unusable_free_index(unsigned int order,
struct contig_page_info *info)
{
/* No free memory is interpreted as all free memory is unusable */
if (info->free_pages == 0)
return 1000;
/*
* Index should be a value between 0 and 1. Return a value to 3
* decimal places.
*
* 0 => no fragmentation
* 1 => high fragmentation
*/
return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
}
static void unusable_show_print(struct seq_file *m,
pg_data_t *pgdat, struct zone *zone)
{
unsigned int order;
int index;
struct contig_page_info info;
seq_printf(m, "Node %d, zone %8s ",
pgdat->node_id,
zone->name);
for (order = 0; order < MAX_ORDER; ++order) {
fill_contig_page_info(zone, order, &info);
index = unusable_free_index(order, &info);
seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
}
seq_putc(m, '\n');
}
/*
* Display unusable free space index
*
* The unusable free space index measures how much of the available free
* memory cannot be used to satisfy an allocation of a given size and is a
* value between 0 and 1. The higher the value, the more of free memory is
* unusable and by implication, the worse the external fragmentation is. This
* can be expressed as a percentage by multiplying by 100.
*/
static int unusable_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
/* check memoryless node */
if (!node_state(pgdat->node_id, N_MEMORY))
return 0;
walk_zones_in_node(m, pgdat, unusable_show_print);
return 0;
}
static const struct seq_operations unusable_op = {
.start = frag_start,
.next = frag_next,
.stop = frag_stop,
.show = unusable_show,
};
static int unusable_open(struct inode *inode, struct file *file)
{
return seq_open(file, &unusable_op);
}
static const struct file_operations unusable_file_ops = {
.open = unusable_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static void extfrag_show_print(struct seq_file *m,
pg_data_t *pgdat, struct zone *zone)
{
unsigned int order;
int index;
/* Alloc on stack as interrupts are disabled for zone walk */
struct contig_page_info info;
seq_printf(m, "Node %d, zone %8s ",
pgdat->node_id,
zone->name);
for (order = 0; order < MAX_ORDER; ++order) {
fill_contig_page_info(zone, order, &info);
index = __fragmentation_index(order, &info);
seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
}
seq_putc(m, '\n');
}
/*
* Display fragmentation index for orders that allocations would fail for
*/
static int extfrag_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
walk_zones_in_node(m, pgdat, extfrag_show_print);
return 0;
}
static const struct seq_operations extfrag_op = {
.start = frag_start,
.next = frag_next,
.stop = frag_stop,
.show = extfrag_show,
};
static int extfrag_open(struct inode *inode, struct file *file)
{
return seq_open(file, &extfrag_op);
}
static const struct file_operations extfrag_file_ops = {
.open = extfrag_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init extfrag_debug_init(void)
{
struct dentry *extfrag_debug_root;
extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
if (!extfrag_debug_root)
return -ENOMEM;
if (!debugfs_create_file("unusable_index", 0444,
extfrag_debug_root, NULL, &unusable_file_ops))
goto fail;
if (!debugfs_create_file("extfrag_index", 0444,
extfrag_debug_root, NULL, &extfrag_file_ops))
goto fail;
return 0;
fail:
debugfs_remove_recursive(extfrag_debug_root);
return -ENOMEM;
}
module_init(extfrag_debug_init);
#endif