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/cache.h> |
7 | #include <linux/kernel.h> |
8 | #include <asm/page.h> |
9 | |
10 | struct page_counter { |
11 | /* |
12 | * Make sure 'usage' does not share cacheline with any other field. The |
13 | * memcg->memory.usage is a hot member of struct mem_cgroup. |
14 | */ |
15 | atomic_long_t usage; |
16 | CACHELINE_PADDING(_pad1_); |
17 | |
18 | /* effective memory.min and memory.min usage tracking */ |
19 | unsigned long emin; |
20 | atomic_long_t min_usage; |
21 | atomic_long_t children_min_usage; |
22 | |
23 | /* effective memory.low and memory.low usage tracking */ |
24 | unsigned long elow; |
25 | atomic_long_t low_usage; |
26 | atomic_long_t children_low_usage; |
27 | |
28 | unsigned long watermark; |
29 | unsigned long failcnt; |
30 | |
31 | /* Keep all the read most fields in a separete cacheline. */ |
32 | CACHELINE_PADDING(_pad2_); |
33 | |
34 | unsigned long min; |
35 | unsigned long low; |
36 | unsigned long high; |
37 | unsigned long max; |
38 | struct page_counter *parent; |
39 | } ____cacheline_internodealigned_in_smp; |
40 | |
41 | #if BITS_PER_LONG == 32 |
42 | #define PAGE_COUNTER_MAX LONG_MAX |
43 | #else |
44 | #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE) |
45 | #endif |
46 | |
47 | static inline void page_counter_init(struct page_counter *counter, |
48 | struct page_counter *parent) |
49 | { |
50 | atomic_long_set(v: &counter->usage, i: 0); |
51 | counter->max = PAGE_COUNTER_MAX; |
52 | counter->parent = parent; |
53 | } |
54 | |
55 | static inline unsigned long page_counter_read(struct page_counter *counter) |
56 | { |
57 | return atomic_long_read(v: &counter->usage); |
58 | } |
59 | |
60 | void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); |
61 | void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); |
62 | bool page_counter_try_charge(struct page_counter *counter, |
63 | unsigned long nr_pages, |
64 | struct page_counter **fail); |
65 | void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); |
66 | void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages); |
67 | void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages); |
68 | |
69 | static inline void page_counter_set_high(struct page_counter *counter, |
70 | unsigned long nr_pages) |
71 | { |
72 | WRITE_ONCE(counter->high, nr_pages); |
73 | } |
74 | |
75 | int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages); |
76 | int page_counter_memparse(const char *buf, const char *max, |
77 | unsigned long *nr_pages); |
78 | |
79 | static inline void page_counter_reset_watermark(struct page_counter *counter) |
80 | { |
81 | counter->watermark = page_counter_read(counter); |
82 | } |
83 | |
84 | #endif /* _LINUX_PAGE_COUNTER_H */ |
85 | |