Index: linux-2.6.20-rc4/include/linux/writeback.h
===================================================================
--- linux-2.6.20-rc4.orig/include/linux/writeback.h	2007-01-09 07:19:19.000000000 -0600
+++ linux-2.6.20-rc4/include/linux/writeback.h	2007-01-09 07:43:24.282223620 -0600
@@ -85,7 +85,6 @@ static inline void wait_on_inode(struct 
 int wakeup_pdflush(long nr_pages, nodemask_t *nodes);
 void laptop_io_completion(void);
 void laptop_sync_completion(void);
-void throttle_vm_writeout(void);
 
 /* These are exported to sysctl. */
 extern int dirty_background_ratio;
Index: linux-2.6.20-rc4/mm/page-writeback.c
===================================================================
--- linux-2.6.20-rc4.orig/mm/page-writeback.c	2007-01-09 07:42:46.000000000 -0600
+++ linux-2.6.20-rc4/mm/page-writeback.c	2007-01-09 07:43:53.318941232 -0600
@@ -349,26 +349,6 @@ void balance_dirty_pages_ratelimited_nr(
 }
 EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
 
-void throttle_vm_writeout(void)
-{
-	struct dirty_limits dl;
-
-        for ( ; ; ) {
-		get_dirty_limits(&dl, NULL, &node_online_map);
-
-                /*
-                 * Boost the allowable dirty threshold a bit for page
-                 * allocators so they don't get DoS'ed by heavy writers
-                 */
-                dl.thresh_dirty += dl.thresh_dirty / 10; /* wheeee... */
-
-                if (dl.nr_unstable + dl.nr_writeback <= dl.thresh_dirty)
-                       break;
-                congestion_wait(WRITE, HZ/10);
-        }
-}
-
-
 /*
  * writeback at least _min_pages, and keep writing until the amount of dirty
  * memory is less than the background threshold, or until we're all clean.
Index: linux-2.6.20-rc4/mm/vmscan.c
===================================================================
--- linux-2.6.20-rc4.orig/mm/vmscan.c	2007-01-09 07:42:50.000000000 -0600
+++ linux-2.6.20-rc4/mm/vmscan.c	2007-01-09 07:58:58.458521221 -0600
@@ -949,7 +949,26 @@ static unsigned long shrink_zone(int pri
 		}
 	}
 
-	throttle_vm_writeout();
+	/*
+	 * Throttle writeouts to this zone.
+	 *
+ 	 * This is similar to the ratio calculation in get_dirty_limits()
+	 * but we are only interested in the dirty ratio for this zone and
+	 * get_dirty_limits only operates on nodes or the system as a whole.
+	 *
+	 * Howeve, we ignore the boundary checks for dirty_ratio here since
+	 * there is not much harm done if the user specifies a too high or
+	 * too low dirty ratio.
+	 */
+	if (zone_page_state(zone, NR_UNSTABLE_NFS) +
+		zone_page_state(zone, NR_WRITEBACK) >
+		(zone->present_pages * vm_dirty_ratio) / 100 +
+		/*
+		 * Boost the allowable dirty threshold a bit for page
+		 * allocators so they don't get DoS'ed by heavy writers
+		 */
+		(zone->present_pages * vm_dirty_ratio) / 1000)
+			congestion_wait(WRITE, HZ/10);
 
 	atomic_dec(&zone->reclaim_in_progress);
 	return nr_reclaimed;