[PATCH 2/4] io_uring/alloc_cache: mark cache success paths as likely

[Caleb Sander Mateos]

The point of a struct io_alloc_cache is to serve allocations from the
cache to avoid a call to kmalloc(). Only very high queue depth workloads
require more concurrent allocations than the fixed-size io_alloc_caches
can provide. So mark the success paths in io_alloc_cache_get() and
io_alloc_cache_put() as likely.

Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
---
 io_uring/alloc_cache.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h
index 962b6e2d04cc..aa007b380f1b 100644
--- a/io_uring/alloc_cache.h
+++ b/io_uring/alloc_cache.h
@@ -19,22 +19,22 @@ bool io_alloc_cache_init(struct io_alloc_cache *cache,
 void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp);
 
 static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
 				      void *entry)
 {
-	if (cache->nr_cached < cache->max_cached) {
+	if (likely(cache->nr_cached < cache->max_cached)) {
 		if (!kasan_mempool_poison_object(entry))
 			return false;
 		cache->entries[cache->nr_cached++] = entry;
 		return true;
 	}
 	return false;
 }
 
 static inline void *io_alloc_cache_get(struct io_alloc_cache *cache)
 {
-	if (cache->nr_cached) {
+	if (likely(cache->nr_cached)) {
 		void *entry = cache->entries[--cache->nr_cached];
 
 		/*
 		 * If KASAN is enabled, always clear the initial bytes that
 		 * must be zeroed post alloc, in case any of them overlap
-- 
2.56.0