/* 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 max; struct page_counter *parent; /* 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; }; #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); 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 */