[linux-block.git] / include / linux / page_counter.h

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

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <asm/page.h>

struct page_counter {
	atomic_long_t usage;
	unsigned long min;
	unsigned long low;
	unsigned long max;
	struct page_counter *parent;

	/* effective memory.min and memory.min usage tracking */
	unsigned long emin;
	atomic_long_t min_usage;
	atomic_long_t children_min_usage;

	/* effective memory.low and memory.low usage tracking */
	unsigned long elow;
	atomic_long_t low_usage;
	atomic_long_t children_low_usage;

	/* legacy */
	unsigned long watermark;
	unsigned long failcnt;
};

#if BITS_PER_LONG == 32
#define PAGE_COUNTER_MAX LONG_MAX
#else
#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
#endif

static inline void page_counter_init(struct page_counter *counter,
				     struct page_counter *parent)
{
	atomic_long_set(&counter->usage, 0);
	counter->max = PAGE_COUNTER_MAX;
	counter->parent = parent;
}

static inline unsigned long page_counter_read(struct page_counter *counter)
{
	return atomic_long_read(&counter->usage);
}

void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
bool page_counter_try_charge(struct page_counter *counter,
			     unsigned long nr_pages,
			     struct page_counter **fail);
void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
int page_counter_memparse(const char *buf, const char *max,
			  unsigned long *nr_pages);

static inline void page_counter_reset_watermark(struct page_counter *counter)
{
	counter->watermark = page_counter_read(counter);
}

#endif /* _LINUX_PAGE_COUNTER_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _LINUX_PAGE_COUNTER_H
	3	#define _LINUX_PAGE_COUNTER_H
	4
	5	#include <linux/atomic.h>
	6	#include <linux/kernel.h>
	7	#include <asm/page.h>
	8
	9	struct page_counter {
	10	atomic_long_t usage;
	11	unsigned long min;
	12	unsigned long low;
	13	unsigned long max;
	14	struct page_counter *parent;
	15
	16	/* effective memory.min and memory.min usage tracking */
	17	unsigned long emin;
	18	atomic_long_t min_usage;
	19	atomic_long_t children_min_usage;
	20
	21	/* effective memory.low and memory.low usage tracking */
	22	unsigned long elow;
	23	atomic_long_t low_usage;
	24	atomic_long_t children_low_usage;
	25
	26	/* legacy */
	27	unsigned long watermark;
	28	unsigned long failcnt;
	29	};
	30
	31	#if BITS_PER_LONG == 32
	32	#define PAGE_COUNTER_MAX LONG_MAX
	33	#else
	34	#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
	35	#endif
	36
	37	static inline void page_counter_init(struct page_counter *counter,
	38	struct page_counter *parent)
	39	{
	40	atomic_long_set(&counter->usage, 0);
	41	counter->max = PAGE_COUNTER_MAX;
	42	counter->parent = parent;
	43	}
	44
	45	static inline unsigned long page_counter_read(struct page_counter *counter)
	46	{
	47	return atomic_long_read(&counter->usage);
	48	}
	49
	50	void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
	51	void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
	52	bool page_counter_try_charge(struct page_counter *counter,
	53	unsigned long nr_pages,
	54	struct page_counter **fail);
	55	void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
	56	void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
	57	void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
	58	int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
	59	int page_counter_memparse(const char buf, const char max,
	60	unsigned long *nr_pages);
	61
	62	static inline void page_counter_reset_watermark(struct page_counter *counter)
	63	{
	64	counter->watermark = page_counter_read(counter);
	65	}
	66
	67	#endif /* _LINUX_PAGE_COUNTER_H */