diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 30351f0063ac..bb553c3e955d 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -94,12 +94,12 @@ unsigned long vm_dirty_bytes;
 /*
  * The interval between `kupdate'-style writebacks
  */
-unsigned int dirty_writeback_interval = 5 * 100; /* sentiseconds */
+unsigned int dirty_writeback_interval = 5 * 100; /* centiseconds */
 
 /*
  * The longest time for which data is allowed to remain dirty
  */
-unsigned int dirty_expire_interval = 30 * 100; /* sentiseconds */
+unsigned int dirty_expire_interval = 30 * 100; /* centiseconds */
 
 /*
  * Flag that makes the machine dump writes/reads and block dirtyings.
@@ -770,7 +770,7 @@ static void wb_kupdate(unsigned long arg)
 
 	sync_supers();
 
-	oldest_jif = jiffies - msecs_to_jiffies(dirty_expire_interval);
+	oldest_jif = jiffies - msecs_to_jiffies(dirty_expire_interval * 10);
 	start_jif = jiffies;
 	next_jif = start_jif + msecs_to_jiffies(dirty_writeback_interval * 10);
 	nr_to_write = global_page_state(NR_FILE_DIRTY) +