diff --git a/bsp/apm32/apm32f030r8-miniboard/rtconfig.py b/bsp/apm32/apm32f030r8-miniboard/rtconfig.py
index 2fd6753c9b..eca7e715d3 100644
--- a/bsp/apm32/apm32f030r8-miniboard/rtconfig.py
+++ b/bsp/apm32/apm32f030r8-miniboard/rtconfig.py
@@ -28,7 +28,7 @@ elif CROSS_TOOL == 'iar':
 if os.getenv('RTT_EXEC_PATH'):
     EXEC_PATH = os.getenv('RTT_EXEC_PATH')
 
-BUILD = 'debug'
+BUILD = 'release'
 
 if PLATFORM == 'gcc':
     # toolchains
diff --git a/bsp/apm32/apm32f051r8-evalboard/rtconfig.py b/bsp/apm32/apm32f051r8-evalboard/rtconfig.py
index 2fd6753c9b..eca7e715d3 100644
--- a/bsp/apm32/apm32f051r8-evalboard/rtconfig.py
+++ b/bsp/apm32/apm32f051r8-evalboard/rtconfig.py
@@ -28,7 +28,7 @@ elif CROSS_TOOL == 'iar':
 if os.getenv('RTT_EXEC_PATH'):
     EXEC_PATH = os.getenv('RTT_EXEC_PATH')
 
-BUILD = 'debug'
+BUILD = 'release'
 
 if PLATFORM == 'gcc':
     # toolchains
diff --git a/src/ipc.c b/src/ipc.c
index fd8e9c66bf..4cea8d8a51 100644
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -1351,7 +1351,7 @@ static rt_err_t _rt_mutex_take(rt_mutex_t mutex, rt_int32_t timeout, int suspend
 
     if (mutex->owner == thread)
     {
-        if(mutex->hold < RT_MUTEX_HOLD_MAX)
+        if (mutex->hold < RT_MUTEX_HOLD_MAX)
         {
             /* it's the same thread */
             mutex->hold ++;
diff --git a/src/thread.c b/src/thread.c
index eef7a15376..d9816b5277 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -76,6 +76,44 @@ void rt_thread_resume_sethook(void (*hook)(rt_thread_t thread))
 RT_OBJECT_HOOKLIST_DEFINE(rt_thread_inited);
 #endif /* defined(RT_USING_HOOK) && defined(RT_HOOK_USING_FUNC_PTR) */
 
+#ifdef RT_USING_MUTEX
+static void _thread_detach_from_mutex(rt_thread_t thread)
+{
+    rt_list_t *node;
+    rt_list_t *tmp_list;
+    struct rt_mutex *mutex;
+    rt_base_t level;
+
+    level = rt_spin_lock_irqsave(&thread->spinlock);
+
+    /* check if thread is waiting on a mutex */
+    if ((thread->pending_object) &&
+        (rt_object_get_type(thread->pending_object) == RT_Object_Class_Mutex))
+    {
+        /* remove it from its waiting list */
+        struct rt_mutex *mutex = (struct rt_mutex*)thread->pending_object;
+        rt_mutex_drop_thread(mutex, thread);
+        thread->pending_object = RT_NULL;
+    }
+
+    /* free taken mutex after detaching from waiting, so we don't lost mutex just got */
+    rt_list_for_each_safe(node, tmp_list, &(thread->taken_object_list))
+    {
+        mutex = rt_list_entry(node, struct rt_mutex, taken_list);
+        LOG_D("Thread [%s] exits while holding mutex [%s].\n", thread->parent.name, mutex->parent.parent.name);
+        /* recursively take */
+        mutex->hold = 1;
+        rt_mutex_release(mutex);
+    }
+
+    rt_spin_unlock_irqrestore(&thread->spinlock, level);
+}
+
+#else
+
+static void _thread_detach_from_mutex(rt_thread_t thread) {}
+#endif
+
 static void _thread_exit(void)
 {
     struct rt_thread *thread;
@@ -88,6 +126,8 @@ static void _thread_exit(void)
 
     rt_thread_close(thread);
 
+    _thread_detach_from_mutex(thread);
+
     /* insert to defunct thread list */
     rt_thread_defunct_enqueue(thread);
 
@@ -133,41 +173,6 @@ static void _thread_timeout(void *parameter)
     rt_sched_unlock_n_resched(slvl);
 }
 
-#ifdef RT_USING_MUTEX
-static void _thread_detach_from_mutex(rt_thread_t thread)
-{
-    rt_list_t *node;
-    rt_list_t *tmp_list;
-    struct rt_mutex *mutex;
-    rt_base_t level;
-
-    level = rt_spin_lock_irqsave(&thread->spinlock);
-
-    /* check if thread is waiting on a mutex */
-    if ((thread->pending_object) &&
-        (rt_object_get_type(thread->pending_object) == RT_Object_Class_Mutex))
-    {
-        /* remove it from its waiting list */
-        struct rt_mutex *mutex = (struct rt_mutex*)thread->pending_object;
-        rt_mutex_drop_thread(mutex, thread);
-        thread->pending_object = RT_NULL;
-    }
-
-    /* free taken mutex after detaching from waiting, so we don't lost mutex just got */
-    rt_list_for_each_safe(node, tmp_list, &(thread->taken_object_list))
-    {
-        mutex = rt_list_entry(node, struct rt_mutex, taken_list);
-        rt_mutex_release(mutex);
-    }
-
-    rt_spin_unlock_irqrestore(&thread->spinlock, level);
-}
-
-#else
-
-static void _thread_detach_from_mutex(rt_thread_t thread) {}
-#endif
-
 static rt_err_t _thread_init(struct rt_thread *thread,
                              const char       *name,
                              void (*entry)(void *parameter),