Index: head/sys/kern/subr_blist.c
===================================================================
--- head/sys/kern/subr_blist.c
+++ head/sys/kern/subr_blist.c
@@ -251,6 +251,8 @@
 		    bl->bl_radix);
 		if (blk != SWAPBLK_NONE) {
 			bl->bl_cursor = blk + count;
+			if (bl->bl_cursor == bl->bl_blocks)
+				bl->bl_cursor = 0;
 			return (blk);
 		} else if (bl->bl_cursor != 0)
 			bl->bl_cursor = 0;