We increase cache->nr_cached when we free into the cache but don't decrease when we take from it, so in some time we'll get an empty cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails io_alloc_cache_put() and effectively disables caching. Fixes: 9b797a37c4bd8 ("io_uring: add abstraction around apoll cache") Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> --- io_uring/alloc_cache.h | 1 + 1 file changed, 1 insertion(+) diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h index 3aba7b356320..2fbecaa3a1ba 100644 --- a/io_uring/alloc_cache.h +++ b/io_uring/alloc_cache.h @@ -31,6 +31,7 @@ static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *c entry = container_of(cache->list.next, struct io_cache_entry, node); kasan_unpoison_range(entry, cache->elem_size); cache->list.next = cache->list.next->next; + cache->nr_cached--; return entry; } -- 2.39.1