diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 1833fc9e09cb690ff70c84e389eb2fa8f3c477b4..7a48e5568d46068a8ac1d070e908820295d1591c 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -731,7 +731,8 @@ static enum fullness_group fix_fullness_group(struct size_class *class,
  * to form a zspage for each size class. This is important
  * to reduce wastage due to unusable space left at end of
  * each zspage which is given as:
- *	wastage = Zp - Zp % size_class
+ *     wastage = Zp % class_size
+ *     usage = Zp - wastage
  * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ...
  *
  * For example, for size class of 3/8 * PAGE_SIZE, we should