diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 91d163f8d36b2f69e97bdee62f4224d5c9583676..f13ed76399410e4c4d46731f757d0cbec5181cdf 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -323,18 +323,6 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
 		}
 	}
 
-	/*
-	 * Unreclaimable memory (kernel memory or anonymous memory
-	 * without swap) can bring down the dirtyable pages below
-	 * the zone's dirty balance reserve and the above calculation
-	 * will underflow.  However we still want to add in nodes
-	 * which are below threshold (negative values) to get a more
-	 * accurate calculation but make sure that the total never
-	 * underflows.
-	 */
-	if ((long)x < 0)
-		x = 0;
-
 	/*
 	 * Make sure that the number of highmem pages is never larger
 	 * than the number of the total dirtyable memory. This can only