[linux-2.6-block.git] / include / linux / page_counter.h

#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 count;
	unsigned long limit;
	struct page_counter *parent;

	/* 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->count, 0);
	counter->limit = PAGE_COUNTER_MAX;
	counter->parent = parent;
}

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

void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
int 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);
int page_counter_limit(struct page_counter *counter, unsigned long limit);
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
3e32cb2e JW	1	#ifndef _LINUX_PAGE_COUNTER_H
	2	#define _LINUX_PAGE_COUNTER_H
	3
	4	#include <linux/atomic.h>
	5	#include <linux/kernel.h>
	6	#include <asm/page.h>
	7
	8	struct page_counter {
	9	atomic_long_t count;
	10	unsigned long limit;
	11	struct page_counter *parent;
	12
	13	/* legacy */
	14	unsigned long watermark;
	15	unsigned long failcnt;
	16	};
	17
	18	#if BITS_PER_LONG == 32
	19	#define PAGE_COUNTER_MAX LONG_MAX
	20	#else
	21	#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
	22	#endif
	23
	24	static inline void page_counter_init(struct page_counter *counter,
	25	struct page_counter *parent)
	26	{
	27	atomic_long_set(&counter->count, 0);
	28	counter->limit = PAGE_COUNTER_MAX;
	29	counter->parent = parent;
	30	}
	31
	32	static inline unsigned long page_counter_read(struct page_counter *counter)
	33	{
	34	return atomic_long_read(&counter->count);
	35	}
	36
64f21993	37	void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
3e32cb2e JW	38	void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
	39	int page_counter_try_charge(struct page_counter *counter,
	40	unsigned long nr_pages,
	41	struct page_counter **fail);
64f21993	42	void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
3e32cb2e	43	int page_counter_limit(struct page_counter *counter, unsigned long limit);
650c5e56 JW	44	int page_counter_memparse(const char buf, const char max,
650c5e56 JW	45	unsigned long *nr_pages);
3e32cb2e JW	46
	47	static inline void page_counter_reset_watermark(struct page_counter *counter)
	48	{
	49	counter->watermark = page_counter_read(counter);
	50	}
	51
	52	#endif /* _LINUX_PAGE_COUNTER_H */