diff --git a/block/bio.c b/block/bio.c
index 71e411a0c129501008f3b33e604a03535d84f309..2693f34afb7e9e596bc94c1fc60552131fe93e42 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -26,7 +26,6 @@
 #include "blk-cgroup.h"
 
 #define ALLOC_CACHE_THRESHOLD	16
-#define ALLOC_CACHE_SLACK	64
 #define ALLOC_CACHE_MAX		256
 
 struct bio_alloc_cache {