diff --git a/devicemodel/samples/apl-mrb/launch_uos.sh b/devicemodel/samples/apl-mrb/launch_uos.sh
index 96812b045..0d3411fe1 100755
--- a/devicemodel/samples/apl-mrb/launch_uos.sh
+++ b/devicemodel/samples/apl-mrb/launch_uos.sh
@@ -407,6 +407,13 @@ for i in `ls -d /sys/devices/system/cpu/cpu[1-99]`; do
         echo cpu$idx online=$online
         if [ "$online" = "1" ]; then
                 echo 0 > $i/online
+		online=`cat $i/online`
+		# during boot time, cpu hotplug may be disabled by pci_device_probe during a pci module insmod
+		while [ "$online" = "1" ]; do
+			sleep 1
+			echo 0 > $i/online
+			online=`cat $i/online`
+		done
                 echo $idx > /sys/class/vhm/acrn_vhm/offline_cpu
         fi
 done
diff --git a/devicemodel/samples/nuc/launch_uos.sh b/devicemodel/samples/nuc/launch_uos.sh
index c0455147c..3ce035188 100755
--- a/devicemodel/samples/nuc/launch_uos.sh
+++ b/devicemodel/samples/nuc/launch_uos.sh
@@ -37,6 +37,12 @@ for i in `ls -d /sys/devices/system/cpu/cpu[1-99]`; do
         echo cpu$idx online=$online
         if [ "$online" = "1" ]; then
                 echo 0 > $i/online
+		# during boot time, cpu hotplug may be disabled by pci_device_probe during a pci module insmod
+		while [ "$online" = "1" ]; do
+			sleep 1
+			echo 0 > $i/online
+			online=`cat $i/online`
+		done
                 echo $idx > /sys/class/vhm/acrn_vhm/offline_cpu
         fi
 done