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 37 void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); 38 void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); 39 bool page_counter_try_charge(struct page_counter *counter, 40 unsigned long nr_pages, 41 struct page_counter **fail); 42 void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); 43 int page_counter_limit(struct page_counter *counter, unsigned long limit); 44 int page_counter_memparse(const char *buf, const char *max, 45 unsigned long *nr_pages); 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 */ 53