diff --git a/source/module/monitor_kernel.c b/source/module/monitor_kernel.c
index b6cd892..af5d069 100644
--- a/source/module/monitor_kernel.c
+++ b/source/module/monitor_kernel.c
@@ -21,7 +21,7 @@ struct my_device_data {
 
 static int device_open(struct inode *inode, struct file *file) {
   struct my_device_data *data;
-  printk(KERN_INFO "%s: with pid %d\n", __FUNCTION__, current->pid);
+  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__, current->pid);
   // save pid
   data = kmalloc(sizeof(*data), GFP_KERNEL);
   if (!data)
@@ -32,9 +32,9 @@ static int device_open(struct inode *inode, struct file *file) {
 }
 
 static int device_release(struct inode *inode, struct file *file) {
-  // printk(KERN_INFO "%s\n", __FUNCTION__);
   // load pid
   struct my_device_data *data = file->private_data;
+  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__, data->pid);
   // clear watch with pid
   clear_watch(data->pid);
   kfree(data); // free data memory
diff --git a/source/module/monitor_kernel_lib.c b/source/module/monitor_kernel_lib.c
index 532fdb5..0f30ee9 100644
--- a/source/module/monitor_kernel_lib.c
+++ b/source/module/monitor_kernel_lib.c
@@ -161,7 +161,7 @@ int start_watch_variable(watch_arg warg) {
  * @param pid
  */
 void clear_watch(pid_t pid) {
-  printk(KERN_INFO "clear pid %d 's watch variable\n", pid);
+  printk(KERN_INFO "Clear pid: %d's watch variable\n", pid);
   cancel_all_hrTimer();      // just in case
   del_all_kwarg_by_pid(pid); // delete all kwarg with pid
   free_page_list(pid);       // free page with pid
diff --git a/testcase/helloworld.c b/testcase/helloworld.c
index ae75db5..50eaea6 100644
--- a/testcase/helloworld.c
+++ b/testcase/helloworld.c
@@ -22,7 +22,7 @@ int main()
             .ptr = &temps[i],
             .name = "temp",
             .length_byte = sizeof(int),
-            .threshold = 150 + i,
+            .threshold = 110 + i,
             .unsigned_flag = 0,
             .greater_flag = 1,
             .time_ns = 2000 + (i / 33) * 5000, // on hyper-v, 1us will block all system. 2us just fine, maybe 1us is too short for hyper-v
@@ -48,4 +48,4 @@ int main()
 
     cancel_watch();
     return 0;
-}
\ No newline at end of file
+}