1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _LINUX_PAGE_COUNTER_H
3*4882a593Smuzhiyun #define _LINUX_PAGE_COUNTER_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/atomic.h>
6*4882a593Smuzhiyun #include <linux/kernel.h>
7*4882a593Smuzhiyun #include <asm/page.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun struct page_counter {
10*4882a593Smuzhiyun atomic_long_t usage;
11*4882a593Smuzhiyun unsigned long min;
12*4882a593Smuzhiyun unsigned long low;
13*4882a593Smuzhiyun unsigned long high;
14*4882a593Smuzhiyun unsigned long max;
15*4882a593Smuzhiyun struct page_counter *parent;
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun /* effective memory.min and memory.min usage tracking */
18*4882a593Smuzhiyun unsigned long emin;
19*4882a593Smuzhiyun atomic_long_t min_usage;
20*4882a593Smuzhiyun atomic_long_t children_min_usage;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun /* effective memory.low and memory.low usage tracking */
23*4882a593Smuzhiyun unsigned long elow;
24*4882a593Smuzhiyun atomic_long_t low_usage;
25*4882a593Smuzhiyun atomic_long_t children_low_usage;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /* legacy */
28*4882a593Smuzhiyun unsigned long watermark;
29*4882a593Smuzhiyun unsigned long failcnt;
30*4882a593Smuzhiyun };
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun #if BITS_PER_LONG == 32
33*4882a593Smuzhiyun #define PAGE_COUNTER_MAX LONG_MAX
34*4882a593Smuzhiyun #else
35*4882a593Smuzhiyun #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
36*4882a593Smuzhiyun #endif
37*4882a593Smuzhiyun
page_counter_init(struct page_counter * counter,struct page_counter * parent)38*4882a593Smuzhiyun static inline void page_counter_init(struct page_counter *counter,
39*4882a593Smuzhiyun struct page_counter *parent)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun atomic_long_set(&counter->usage, 0);
42*4882a593Smuzhiyun counter->max = PAGE_COUNTER_MAX;
43*4882a593Smuzhiyun counter->parent = parent;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
page_counter_read(struct page_counter * counter)46*4882a593Smuzhiyun static inline unsigned long page_counter_read(struct page_counter *counter)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun return atomic_long_read(&counter->usage);
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
52*4882a593Smuzhiyun void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
53*4882a593Smuzhiyun bool page_counter_try_charge(struct page_counter *counter,
54*4882a593Smuzhiyun unsigned long nr_pages,
55*4882a593Smuzhiyun struct page_counter **fail);
56*4882a593Smuzhiyun void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
57*4882a593Smuzhiyun void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
58*4882a593Smuzhiyun void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
59*4882a593Smuzhiyun
page_counter_set_high(struct page_counter * counter,unsigned long nr_pages)60*4882a593Smuzhiyun static inline void page_counter_set_high(struct page_counter *counter,
61*4882a593Smuzhiyun unsigned long nr_pages)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun WRITE_ONCE(counter->high, nr_pages);
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
67*4882a593Smuzhiyun int page_counter_memparse(const char *buf, const char *max,
68*4882a593Smuzhiyun unsigned long *nr_pages);
69*4882a593Smuzhiyun
page_counter_reset_watermark(struct page_counter * counter)70*4882a593Smuzhiyun static inline void page_counter_reset_watermark(struct page_counter *counter)
71*4882a593Smuzhiyun {
72*4882a593Smuzhiyun counter->watermark = page_counter_read(counter);
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun #endif /* _LINUX_PAGE_COUNTER_H */
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