diff --git a/mm/percpu.c b/mm/percpu.c
index e12ab708fe15bfa6ecb3977731517a2c2befb2d8..928c8889eb1ff49ceb611f3d9e7ea4fcbf6e0962 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -98,7 +98,10 @@
 
 #include "percpu-internal.h"
 
-/* the slots are sorted by free bytes left, 1-31 bytes share the same slot */
+/*
+ * The slots are sorted by the size of the biggest continuous free area.
+ * 1-31 bytes share the same slot.
+ */
 #define PCPU_SLOT_BASE_SHIFT		5
 /* chunks in slots below this are subject to being sidelined on failed alloc */
 #define PCPU_SLOT_FAIL_THRESHOLD	3