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 8struct 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 24static 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 32static inline unsigned long page_counter_read(struct page_counter *counter) 33{ 34 return atomic_long_read(&counter->count); 35} 36 37void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); 38void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); 39int page_counter_try_charge(struct page_counter *counter, 40 unsigned long nr_pages, 41 struct page_counter **fail); 42void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); 43int page_counter_limit(struct page_counter *counter, unsigned long limit); 44int page_counter_memparse(const char *buf, const char *max, 45 unsigned long *nr_pages); 46 47static 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 */ 53