110 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _LINUX_PAGE_COUNTER_H
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| #define _LINUX_PAGE_COUNTER_H
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| 
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| #include <linux/atomic.h>
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| #include <linux/cache.h>
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| #include <linux/limits.h>
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| #include <asm/page.h>
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| 
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| struct page_counter {
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| 	/*
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| 	 * Make sure 'usage' does not share cacheline with any other field. The
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| 	 * memcg->memory.usage is a hot member of struct mem_cgroup.
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| 	 */
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| 	atomic_long_t usage;
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| 	CACHELINE_PADDING(_pad1_);
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| 
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| 	/* effective memory.min and memory.min usage tracking */
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| 	unsigned long emin;
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| 	atomic_long_t min_usage;
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| 	atomic_long_t children_min_usage;
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| 
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| 	/* effective memory.low and memory.low usage tracking */
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| 	unsigned long elow;
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| 	atomic_long_t low_usage;
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| 	atomic_long_t children_low_usage;
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| 
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| 	unsigned long watermark;
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| 	/* Latest cg2 reset watermark */
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| 	unsigned long local_watermark;
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| 	unsigned long failcnt;
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| 
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| 	/* Keep all the read most fields in a separete cacheline. */
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| 	CACHELINE_PADDING(_pad2_);
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| 
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| 	bool protection_support;
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| 	unsigned long min;
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| 	unsigned long low;
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| 	unsigned long high;
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| 	unsigned long max;
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| 	struct page_counter *parent;
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| } ____cacheline_internodealigned_in_smp;
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| 
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| #if BITS_PER_LONG == 32
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| #define PAGE_COUNTER_MAX LONG_MAX
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| #else
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| #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
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| #endif
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| 
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| /*
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|  * Protection is supported only for the first counter (with id 0).
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|  */
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| static inline void page_counter_init(struct page_counter *counter,
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| 				     struct page_counter *parent,
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| 				     bool protection_support)
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| {
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| 	counter->usage = (atomic_long_t)ATOMIC_LONG_INIT(0);
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| 	counter->max = PAGE_COUNTER_MAX;
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| 	counter->parent = parent;
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| 	counter->protection_support = protection_support;
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| }
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| 
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| static inline unsigned long page_counter_read(struct page_counter *counter)
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| {
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| 	return atomic_long_read(&counter->usage);
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| }
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| 
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| void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
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| void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
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| bool page_counter_try_charge(struct page_counter *counter,
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| 			     unsigned long nr_pages,
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| 			     struct page_counter **fail);
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| void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
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| void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
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| void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
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| 
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| static inline void page_counter_set_high(struct page_counter *counter,
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| 					 unsigned long nr_pages)
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| {
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| 	WRITE_ONCE(counter->high, nr_pages);
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| }
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| 
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| int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
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| int page_counter_memparse(const char *buf, const char *max,
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| 			  unsigned long *nr_pages);
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| 
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| static inline void page_counter_reset_watermark(struct page_counter *counter)
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| {
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| 	unsigned long usage = page_counter_read(counter);
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| 
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| 	/*
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| 	 * Update local_watermark first, so it's always <= watermark
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| 	 * (modulo CPU/compiler re-ordering)
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| 	 */
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| 	counter->local_watermark = usage;
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| 	counter->watermark = usage;
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| }
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| 
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| #ifdef CONFIG_MEMCG
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| void page_counter_calculate_protection(struct page_counter *root,
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| 				       struct page_counter *counter,
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| 				       bool recursive_protection);
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| #else
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| static inline void page_counter_calculate_protection(struct page_counter *root,
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| 						     struct page_counter *counter,
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| 						     bool recursive_protection) {}
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| #endif
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| 
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| #endif /* _LINUX_PAGE_COUNTER_H */
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