| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_PAGE_COUNTER_H |
| #define _LINUX_PAGE_COUNTER_H |
| |
| #include <linux/atomic.h> |
| #include <linux/kernel.h> |
| #include <asm/page.h> |
| |
| struct page_counter { |
| atomic_long_t usage; |
| unsigned long min; |
| unsigned long low; |
| unsigned long high; |
| unsigned long max; |
| |
| /* effective memory.min and memory.min usage tracking */ |
| unsigned long emin; |
| atomic_long_t min_usage; |
| atomic_long_t children_min_usage; |
| |
| /* effective memory.low and memory.low usage tracking */ |
| unsigned long elow; |
| atomic_long_t low_usage; |
| atomic_long_t children_low_usage; |
| |
| /* legacy */ |
| unsigned long watermark; |
| unsigned long failcnt; |
| |
| /* |
| * 'parent' is placed here to be far from 'usage' to reduce |
| * cache false sharing, as 'usage' is written mostly while |
| * parent is frequently read for cgroup's hierarchical |
| * counting nature. |
| */ |
| struct page_counter *parent; |
| }; |
| |
| #if BITS_PER_LONG == 32 |
| #define PAGE_COUNTER_MAX LONG_MAX |
| #else |
| #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE) |
| #endif |
| |
| static inline void page_counter_init(struct page_counter *counter, |
| struct page_counter *parent) |
| { |
| atomic_long_set(&counter->usage, 0); |
| counter->max = PAGE_COUNTER_MAX; |
| counter->parent = parent; |
| } |
| |
| static inline unsigned long page_counter_read(struct page_counter *counter) |
| { |
| return atomic_long_read(&counter->usage); |
| } |
| |
| void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); |
| void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); |
| bool page_counter_try_charge(struct page_counter *counter, |
| unsigned long nr_pages, |
| struct page_counter **fail); |
| void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); |
| void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages); |
| void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages); |
| |
| static inline void page_counter_set_high(struct page_counter *counter, |
| unsigned long nr_pages) |
| { |
| WRITE_ONCE(counter->high, nr_pages); |
| } |
| |
| int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages); |
| int page_counter_memparse(const char *buf, const char *max, |
| unsigned long *nr_pages); |
| |
| static inline void page_counter_reset_watermark(struct page_counter *counter) |
| { |
| counter->watermark = page_counter_read(counter); |
| } |
| |
| #endif /* _LINUX_PAGE_COUNTER_H */ |