diff -r 9d8d6b93114e tools/libxl/libxl.c
--- a/tools/libxl/libxl.c	Mon Oct 18 15:24:39 2010 +0200
+++ b/tools/libxl/libxl.c	Tue Oct 19 10:29:00 2010 +0200
@@ -2836,7 +2836,7 @@ retry:
     free_mem_slack_s = libxl__xs_read(gc, XBT_NULL, free_mem_slack_path);
     if (!free_mem_slack_s) {
         rc = libxl__fill_dom0_memory_info(gc, &target_memkb);
-        if (rc < 0)
+        if (rc <= 0)
             return rc;
         goto retry;
     } else {