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	 9731bc9855
			
		
	
	
		9731bc9855
		
	
	
	
	
		
			
			Caches like this tend to grow to the peak size, and then never get any smaller. Impose a max limit on the size, to prevent it from growing too big. A somewhat randomly chosen 512 is the max size we'll allow the cache to get. If a batch of frees come in and would bring it over that, we simply start kfree'ing the surplus. Signed-off-by: Jens Axboe <axboe@kernel.dk>
		
			
				
	
	
		
			53 lines
		
	
	
	
		
			1.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			53 lines
		
	
	
	
		
			1.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef IOU_ALLOC_CACHE_H
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| #define IOU_ALLOC_CACHE_H
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| 
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| /*
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|  * Don't allow the cache to grow beyond this size.
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|  */
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| #define IO_ALLOC_CACHE_MAX	512
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| 
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| struct io_cache_entry {
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| 	struct hlist_node	node;
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| };
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| 
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| static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
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| 				      struct io_cache_entry *entry)
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| {
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| 	if (cache->nr_cached < IO_ALLOC_CACHE_MAX) {
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| 		cache->nr_cached++;
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| 		hlist_add_head(&entry->node, &cache->list);
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| 		return true;
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| 	}
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| 	return false;
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| }
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| 
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| static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache)
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| {
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| 	if (!hlist_empty(&cache->list)) {
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| 		struct hlist_node *node = cache->list.first;
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| 
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| 		hlist_del(node);
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| 		return container_of(node, struct io_cache_entry, node);
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| 	}
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| 
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| 	return NULL;
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| }
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| 
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| static inline void io_alloc_cache_init(struct io_alloc_cache *cache)
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| {
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| 	INIT_HLIST_HEAD(&cache->list);
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| 	cache->nr_cached = 0;
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| }
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| 
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| static inline void io_alloc_cache_free(struct io_alloc_cache *cache,
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| 					void (*free)(struct io_cache_entry *))
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| {
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| 	while (!hlist_empty(&cache->list)) {
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| 		struct hlist_node *node = cache->list.first;
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| 
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| 		hlist_del(node);
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| 		free(container_of(node, struct io_cache_entry, node));
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| 	}
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| 	cache->nr_cached = 0;
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| }
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| #endif
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