top: add config option and code for global CPU % display

diff --git a/docs/keep_data_small.txt b/docs/keep_data_small.txt
index f88fe07..3ddbd81 100644
--- a/docs/keep_data_small.txt
+++ b/docs/keep_data_small.txt
@@ -43,6 +43,16 @@
 
 On 32-bit kernel we need ~26k per applet.
 
+Script:
+
+i=1000; while test $i != 0; do
+        echo -n .
+        busybox sleep 30 &
+        i=$((i - 1))
+done
+echo
+wait
+
 (Data from NOMMU arches are sought. Provide 'size busybox' output too)