include/linux/vmstat.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_VMSTAT_H
#define _LINUX_VMSTAT_H

#include <linux/types.h>
#include <linux/percpu.h>
#include <linux/mmzone.h>
#include <linux/vm_event_item.h>
#include <linux/atomic.h>
#include <linux/static_key.h>
#include <linux/mmdebug.h>

extern int sysctl_stat_interval;

#ifdef CONFIG_NUMA
#define ENABLE_NUMA_STAT   1
#define DISABLE_NUMA_STAT   0
extern int sysctl_vm_numa_stat;
DECLARE_STATIC_KEY_TRUE(vm_numa_stat_key);
int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
		void *buffer, size_t *length, loff_t *ppos);
#endif

struct reclaim_stat {
	unsigned nr_dirty;
	unsigned nr_unqueued_dirty;
	unsigned nr_congested;
	unsigned nr_writeback;
	unsigned nr_immediate;
	unsigned nr_pageout;
	unsigned nr_activate[ANON_AND_FILE];
	unsigned nr_ref_keep;
	unsigned nr_unmap_fail;
	unsigned nr_lazyfree_fail;
};

enum writeback_stat_item {
	NR_DIRTY_THRESHOLD,
	NR_DIRTY_BG_THRESHOLD,
	NR_VM_WRITEBACK_STAT_ITEMS,
};

#ifdef CONFIG_VM_EVENT_COUNTERS
/*
 * Light weight per cpu counter implementation.
 *
 * Counters should only be incremented and no critical kernel component
 * should rely on the counter values.
 *
 * Counters are handled completely inline. On many platforms the code
 * generated will simply be the increment of a global address.
 */

struct vm_event_state {
	unsigned long event[NR_VM_EVENT_ITEMS];
};

DECLARE_PER_CPU(struct vm_event_state, vm_event_states);

/*
 * vm counters are allowed to be racy. Use raw_cpu_ops to avoid the
 * local_irq_disable overhead.
 */
static inline void __count_vm_event(enum vm_event_item item)
{
	raw_cpu_inc(vm_event_states.event[item]);
}

static inline void count_vm_event(enum vm_event_item item)
{
	this_cpu_inc(vm_event_states.event[item]);
}

static inline void __count_vm_events(enum vm_event_item item, long delta)
{
	raw_cpu_add(vm_event_states.event[item], delta);
}

static inline void count_vm_events(enum vm_event_item item, long delta)
{
	this_cpu_add(vm_event_states.event[item], delta);
}

extern void all_vm_events(unsigned long *);

extern void vm_events_fold_cpu(int cpu);

#else

/* Disable counters */
static inline void count_vm_event(enum vm_event_item item)
{
}
static inline void count_vm_events(enum vm_event_item item, long delta)
{
}
static inline void __count_vm_event(enum vm_event_item item)
{
}
static inline void __count_vm_events(enum vm_event_item item, long delta)
{
}
static inline void all_vm_events(unsigned long *ret)
{
}
static inline void vm_events_fold_cpu(int cpu)
{
}

#endif /* CONFIG_VM_EVENT_COUNTERS */

#ifdef CONFIG_NUMA_BALANCING
#define count_vm_numa_event(x)     count_vm_event(x)
#define count_vm_numa_events(x, y) count_vm_events(x, y)
#else
#define count_vm_numa_event(x) do {} while (0)
#define count_vm_numa_events(x, y) do { (void)(y); } while (0)
#endif /* CONFIG_NUMA_BALANCING */

#ifdef CONFIG_DEBUG_TLBFLUSH
#define count_vm_tlb_event(x)	   count_vm_event(x)
#define count_vm_tlb_events(x, y)  count_vm_events(x, y)
#else
#define count_vm_tlb_event(x)     do {} while (0)
#define count_vm_tlb_events(x, y) do { (void)(y); } while (0)
#endif

#ifdef CONFIG_DEBUG_VM_VMACACHE
#define count_vm_vmacache_event(x) count_vm_event(x)
#else
#define count_vm_vmacache_event(x) do {} while (0)
#endif

#define __count_zid_vm_events(item, zid, delta) \
	__count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta)

/*
 * Zone and node-based page accounting with per cpu differentials.
 */
extern atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS];
extern atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS];
extern atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS];

#ifdef CONFIG_NUMA
static inline void zone_numa_state_add(long x, struct zone *zone,
				 enum numa_stat_item item)
{
	atomic_long_add(x, &zone->vm_numa_stat[item]);
	atomic_long_add(x, &vm_numa_stat[item]);
}

static inline unsigned long global_numa_state(enum numa_stat_item item)
{
	long x = atomic_long_read(&vm_numa_stat[item]);

	return x;
}

static inline unsigned long zone_numa_state_snapshot(struct zone *zone,
					enum numa_stat_item item)
{
	long x = atomic_long_read(&zone->vm_numa_stat[item]);
	int cpu;

	for_each_online_cpu(cpu)
		x += per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item];

	return x;
}
#endif /* CONFIG_NUMA */

static inline void zone_page_state_add(long x, struct zone *zone,
				 enum zone_stat_item item)
{
	atomic_long_add(x, &zone->vm_stat[item]);
	atomic_long_add(x, &vm_zone_stat[item]);
}

static inline void node_page_state_add(long x, struct pglist_data *pgdat,
				 enum node_stat_item item)
{
	atomic_long_add(x, &pgdat->vm_stat[item]);
	atomic_long_add(x, &vm_node_stat[item]);
}

static inline unsigned long global_zone_page_state(enum zone_stat_item item)
{
	long x = atomic_long_read(&vm_zone_stat[item]);
#ifdef CONFIG_SMP
	if (x < 0)
		x = 0;
#endif
	return x;
}

static inline
unsigned long global_node_page_state_pages(enum node_stat_item item)
{
	long x = atomic_long_read(&vm_node_stat[item]);
#ifdef CONFIG_SMP
	if (x < 0)
		x = 0;
#endif
	return x;
}

static inline unsigned long global_node_page_state(enum node_stat_item item)
{
	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));

	return global_node_page_state_pages(item);
}

static inline unsigned long zone_page_state(struct zone *zone,
					enum zone_stat_item item)
{
	long x = atomic_long_read(&zone->vm_stat[item]);
#ifdef CONFIG_SMP
	if (x < 0)
		x = 0;
#endif
	return x;
}

/*
 * More accurate version that also considers the currently pending
 * deltas. For that we need to loop over all cpus to find the current
 * deltas. There is no synchronization so the result cannot be
 * exactly accurate either.
 */
static inline unsigned long zone_page_state_snapshot(struct zone *zone,
					enum zone_stat_item item)
{
	long x = atomic_long_read(&zone->vm_stat[item]);

#ifdef CONFIG_SMP
	int cpu;
	for_each_online_cpu(cpu)
		x += per_cpu_ptr(zone->pageset, cpu)->vm_stat_diff[item];

	if (x < 0)
		x = 0;
#endif
	return x;
}

#ifdef CONFIG_NUMA
extern void __inc_numa_state(struct zone *zone, enum numa_stat_item item);
extern unsigned long sum_zone_node_page_state(int node,
					      enum zone_stat_item item);
extern unsigned long sum_zone_numa_state(int node, enum numa_stat_item item);
extern unsigned long node_page_state(struct pglist_data *pgdat,
						enum node_stat_item item);
extern unsigned long node_page_state_pages(struct pglist_data *pgdat,
					   enum node_stat_item item);
#else
#define sum_zone_node_page_state(node, item) global_zone_page_state(item)
#define node_page_state(node, item) global_node_page_state(item)
#define node_page_state_pages(node, item) global_node_page_state_pages(item)
#endif /* CONFIG_NUMA */

#ifdef CONFIG_SMP
void __mod_zone_page_state(struct zone *, enum zone_stat_item item, long);
void __inc_zone_page_state(struct page *, enum zone_stat_item);
void __dec_zone_page_state(struct page *, enum zone_stat_item);

void __mod_node_page_state(struct pglist_data *, enum node_stat_item item, long);
void __inc_node_page_state(struct page *, enum node_stat_item);
void __dec_node_page_state(struct page *, enum node_stat_item);

void mod_zone_page_state(struct zone *, enum zone_stat_item, long);
void inc_zone_page_state(struct page *, enum zone_stat_item);
void dec_zone_page_state(struct page *, enum zone_stat_item);

void mod_node_page_state(struct pglist_data *, enum node_stat_item, long);
void inc_node_page_state(struct page *, enum node_stat_item);
void dec_node_page_state(struct page *, enum node_stat_item);

extern void inc_node_state(struct pglist_data *, enum node_stat_item);
extern void __inc_zone_state(struct zone *, enum zone_stat_item);
extern void __inc_node_state(struct pglist_data *, enum node_stat_item);
extern void dec_zone_state(struct zone *, enum zone_stat_item);
extern void __dec_zone_state(struct zone *, enum zone_stat_item);
extern void __dec_node_state(struct pglist_data *, enum node_stat_item);

void quiet_vmstat(void);
void cpu_vm_stats_fold(int cpu);
void refresh_zone_stat_thresholds(void);

struct ctl_table;
int vmstat_refresh(struct ctl_table *, int write, void *buffer, size_t *lenp,
		loff_t *ppos);

void drain_zonestat(struct zone *zone, struct per_cpu_pageset *);

int calculate_pressure_threshold(struct zone *zone);
int calculate_normal_threshold(struct zone *zone);
void set_pgdat_percpu_threshold(pg_data_t *pgdat,
				int (*calculate_pressure)(struct zone *));
#else /* CONFIG_SMP */

/*
 * We do not maintain differentials in a single processor configuration.
 * The functions directly modify the zone and global counters.
 */
static inline void __mod_zone_page_state(struct zone *zone,
			enum zone_stat_item item, long delta)
{
	zone_page_state_add(delta, zone, item);
}

static inline void __mod_node_page_state(struct pglist_data *pgdat,
			enum node_stat_item item, int delta)
{
	if (vmstat_item_in_bytes(item)) {
		VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
		delta >>= PAGE_SHIFT;
	}

	node_page_state_add(delta, pgdat, item);
}

static inline void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
	atomic_long_inc(&zone->vm_stat[item]);
	atomic_long_inc(&vm_zone_stat[item]);
}

static inline void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
{
	atomic_long_inc(&pgdat->vm_stat[item]);
	atomic_long_inc(&vm_node_stat[item]);
}

static inline void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
{
	atomic_long_dec(&zone->vm_stat[item]);
	atomic_long_dec(&vm_zone_stat[item]);
}

static inline void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
{
	atomic_long_dec(&pgdat->vm_stat[item]);
	atomic_long_dec(&vm_node_stat[item]);
}

static inline void __inc_zone_page_state(struct page *page,
			enum zone_stat_item item)
{
	__inc_zone_state(page_zone(page), item);
}

static inline void __inc_node_page_state(struct page *page,
			enum node_stat_item item)
{
	__inc_node_state(page_pgdat(page), item);
}


static inline void __dec_zone_page_state(struct page *page,
			enum zone_stat_item item)
{
	__dec_zone_state(page_zone(page), item);
}

static inline void __dec_node_page_state(struct page *page,
			enum node_stat_item item)
{
	__dec_node_state(page_pgdat(page), item);
}


/*
 * We only use atomic operations to update counters. So there is no need to
 * disable interrupts.
 */
#define inc_zone_page_state __inc_zone_page_state
#define dec_zone_page_state __dec_zone_page_state
#define mod_zone_page_state __mod_zone_page_state

#define inc_node_page_state __inc_node_page_state
#define dec_node_page_state __dec_node_page_state
#define mod_node_page_state __mod_node_page_state

#define inc_zone_state __inc_zone_state
#define inc_node_state __inc_node_state
#define dec_zone_state __dec_zone_state

#define set_pgdat_percpu_threshold(pgdat, callback) { }

static inline void refresh_zone_stat_thresholds(void) { }
static inline void cpu_vm_stats_fold(int cpu) { }
static inline void quiet_vmstat(void) { }

static inline void drain_zonestat(struct zone *zone,
			struct per_cpu_pageset *pset) { }
#endif		/* CONFIG_SMP */

static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
					     int migratetype)
{
	__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
	if (is_migrate_cma(migratetype))
		__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
}

extern const char * const vmstat_text[];

static inline const char *zone_stat_name(enum zone_stat_item item)
{
	return vmstat_text[item];
}

#ifdef CONFIG_NUMA
static inline const char *numa_stat_name(enum numa_stat_item item)
{
	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
			   item];
}
#endif /* CONFIG_NUMA */

static inline const char *node_stat_name(enum node_stat_item item)
{
	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
			   NR_VM_NUMA_STAT_ITEMS +
			   item];
}

static inline const char *lru_list_name(enum lru_list lru)
{
	return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
}

static inline const char *writeback_stat_name(enum writeback_stat_item item)
{
	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
			   NR_VM_NUMA_STAT_ITEMS +
			   NR_VM_NODE_STAT_ITEMS +
			   item];
}

#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
static inline const char *vm_event_name(enum vm_event_item item)
{
	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
			   NR_VM_NUMA_STAT_ITEMS +
			   NR_VM_NODE_STAT_ITEMS +
			   NR_VM_WRITEBACK_STAT_ITEMS +
			   item];
}
#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */

#endif /* _LINUX_VMSTAT_H */