Index: linux-2.6/include/linux/mmzone.h
===================================================================
--- linux-2.6.orig/include/linux/mmzone.h	2008-04-10 11:06:52.000000000 -0700
+++ linux-2.6/include/linux/mmzone.h	2008-04-10 11:08:04.000000000 -0700
@@ -263,6 +263,7 @@
 	unsigned long		nr_scan_active;
 	unsigned long		nr_scan_inactive;
 	unsigned long		pages_scanned;	   /* since last reclaim */
+	unsigned long		slab_objects_freed; /* Since last slab defrag */
 	unsigned long		flags;		   /* zone flags, see below */
 
 	/* Zone statistics */
Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h	2008-04-10 11:06:52.000000000 -0700
+++ linux-2.6/include/linux/slub_def.h	2008-04-10 11:08:04.000000000 -0700
@@ -91,7 +91,6 @@
 	struct kmem_cache_order_objects min;
 	gfp_t allocflags;	/* gfp flags to use on each alloc */
 	int refcount;		/* Refcount for slab cache destroy */
-	unsigned long next_defrag;
 	void (*ctor)(struct kmem_cache *, void *);
 	/*
 	 * Called with slab lock held and interrupts disabled.
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2008-04-10 11:06:52.000000000 -0700
+++ linux-2.6/mm/slub.c	2008-04-10 11:08:04.000000000 -0700
@@ -2985,9 +2985,6 @@
 
 	list_for_each_entry(s, &slab_caches, list) {
 
-		if (time_before(jiffies, s->next_defrag))
-			continue;
-
 		/*
 		 * Defragmentable caches come first. If the slab cache is not
 		 * defragmentable then we can stop traversing the list.
@@ -3004,11 +3001,6 @@
 		} else
 			reclaimed = __kmem_cache_shrink(s, node, MAX_PARTIAL);
 
-		if (reclaimed)
-			s->next_defrag = jiffies + HZ / 10;
-		else
-			s->next_defrag = jiffies + HZ;
-
 		slabs += reclaimed;
 	}
 	up_read(&slub_lock);
Index: linux-2.6/mm/vmscan.c
===================================================================
--- linux-2.6.orig/mm/vmscan.c	2008-04-10 11:06:52.000000000 -0700
+++ linux-2.6/mm/vmscan.c	2008-04-10 11:24:02.000000000 -0700
@@ -234,8 +234,34 @@
 		shrinker->nr += total_scan;
 	}
 	up_read(&shrinker_rwsem);
-	if (ret && (gfp_mask & __GFP_FS))
-		kmem_cache_defrag(zone ? zone_to_nid(zone) : -1);
+
+	/*
+	 * "ret" doesnt really contain the freed object count. The shrinkers
+	 * fake it. Gotta go with what we are getting though.
+	 *
+	 * Handling of the freed object counter is also racy. If we get the
+	 * wrong counts then we may unnecessarily do a defrag pass or defer
+	 * one. "ret" is already faked. So this is just increasing
+	 * the already existing fuzziness to get some notion as to when
+	 * to initiate slab defrag which will hopefully be okay.
+	 */
+	if (zone) {
+		/* balance_pgdat running on a zone so we only scan one node */
+		zone->slab_objects_freed += ret;
+		if (zone->slab_objects_freed > 100 && (gfp_mask & __GFP_FS)) {
+			zone->slab_objects_freed = 0;
+			kmem_cache_defrag(zone_to_nid(zone));
+		}
+	} else {
+		static unsigned long global_objects_freed = 0;
+
+		/* Direct (and thus global) reclaim. Scan all nodes */
+		global_objects_freed += ret;
+		if (global_objects_freed > 100 && (gfp_mask & __GFP_FS)) {
+			global_objects_freed = 0;
+			kmem_cache_defrag(-1);
+		}
+	}
 	return ret;
 }