Index: linux-2.6.21-rc7-mm2/mm/slub.c
===================================================================
--- linux-2.6.21-rc7-mm2.orig/mm/slub.c	2007-04-27 04:40:25.000000000 -0700
+++ linux-2.6.21-rc7-mm2/mm/slub.c	2007-04-27 04:40:29.000000000 -0700
@@ -2237,14 +2237,21 @@ int kmem_cache_shrink(struct kmem_cache 
 		 * the upper limit.
 		 */
 		list_for_each_entry_safe(page, t, &n->partial, lru) {
-			if (!page->inuse) {
+			if (!page->inuse && slab_trylock(page)) {
+				/*
+				 * Must hold slab lock here because slab_free
+				 * may have freed the last object and be
+				 * waiting to release the slab.
+				 */
 				list_del(&page->lru);
 				n->nr_partial--;
+				slab_unlock(page);
 				discard_slab(s, page);
-			} else
-			if (n->nr_partial > MAX_PARTIAL)
-				list_move(&page->lru,
+			} else {
+				if (n->nr_partial > MAX_PARTIAL)
+					list_move(&page->lru,
 					slabs_by_inuse + page->inuse);
+			}
 		}
 
 		if (n->nr_partial <= MAX_PARTIAL)
@@ -2254,7 +2261,7 @@ int kmem_cache_shrink(struct kmem_cache 
 		 * Rebuild the partial list with the slabs filled up
 		 * most first and the least used slabs at the end.
 		 */
-		for (i = s->objects - 1; i > 0; i--)
+		for (i = s->objects - 1; i >= 0; i--)
 			list_splice(slabs_by_inuse + i, n->partial.prev);
 
 	out: