Make sure the output is shown at the end of the run by sleeping longe…

…r -- killing engine really takes time

examples/kv_transfer/disagg_prefill_example.sh

@@ -86,7 +86,7 @@ output2=$(curl -s http://localhost:8000/v1/completions \
 ps -e | grep pt_main_thread | awk '{print $1}' | xargs kill -9 > /dev/null 2>&1
 pkill -f python3 > /dev/null 2>&1
 
-sleep 3
+sleep 4
 
 # Print the outputs of the curl requests
 echo ""