1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_PAGE_COUNTER_H
3 #define _LINUX_PAGE_COUNTER_H
5 #include <linux/atomic.h>
6 #include <linux/kernel.h>
14 struct page_counter
*parent
;
16 /* effective memory.min and memory.min usage tracking */
18 atomic_long_t min_usage
;
19 atomic_long_t children_min_usage
;
21 /* effective memory.low and memory.low usage tracking */
23 atomic_long_t low_usage
;
24 atomic_long_t children_low_usage
;
27 unsigned long watermark
;
28 unsigned long failcnt
;
31 #if BITS_PER_LONG == 32
32 #define PAGE_COUNTER_MAX LONG_MAX
34 #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
37 static inline void page_counter_init(struct page_counter
*counter
,
38 struct page_counter
*parent
)
40 atomic_long_set(&counter
->usage
, 0);
41 counter
->max
= PAGE_COUNTER_MAX
;
42 counter
->parent
= parent
;
45 static inline unsigned long page_counter_read(struct page_counter
*counter
)
47 return atomic_long_read(&counter
->usage
);
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
);
62 static inline void page_counter_reset_watermark(struct page_counter
*counter
)
64 counter
->watermark
= page_counter_read(counter
);
67 #endif /* _LINUX_PAGE_COUNTER_H */