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linux/io_uring/alloc_cache.h
Jens Axboe 9731bc9855 io_uring: impose max limit on apoll cache
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>
2022-07-24 18:39:17 -06:00

54 lines
1.1 KiB
C

#ifndef IOU_ALLOC_CACHE_H
#define IOU_ALLOC_CACHE_H
/*
* Don't allow the cache to grow beyond this size.
*/
#define IO_ALLOC_CACHE_MAX 512
struct io_cache_entry {
struct hlist_node node;
};
static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
struct io_cache_entry *entry)
{
if (cache->nr_cached < IO_ALLOC_CACHE_MAX) {
cache->nr_cached++;
hlist_add_head(&entry->node, &cache->list);
return true;
}
return false;
}
static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache)
{
if (!hlist_empty(&cache->list)) {
struct hlist_node *node = cache->list.first;
hlist_del(node);
return container_of(node, struct io_cache_entry, node);
}
return NULL;
}
static inline void io_alloc_cache_init(struct io_alloc_cache *cache)
{
INIT_HLIST_HEAD(&cache->list);
cache->nr_cached = 0;
}
static inline void io_alloc_cache_free(struct io_alloc_cache *cache,
void (*free)(struct io_cache_entry *))
{
while (!hlist_empty(&cache->list)) {
struct hlist_node *node = cache->list.first;
hlist_del(node);
free(container_of(node, struct io_cache_entry, node));
}
cache->nr_cached = 0;
}
#endif