diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
index da65da17f..ff48dbc83 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
@@ -104,6 +104,7 @@ struct SchedulerRightGroup {
 
 struct XiziTaskManager {
     struct double_list_node task_list_head[TASK_MAX_PRIORITY]; /* list of task control blocks that are allocated */
+    struct double_list_node task_running_list_head;
     struct double_list_node task_blocked_list_head;
     struct slab_allocator task_allocator;
     struct slab_allocator task_buddy_allocator;
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
index ca5384910..1f270af54 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
@@ -40,6 +40,11 @@ int sys_exit(struct TaskMicroDescriptor* ptask)
 {
     assert(ptask != NULL);
     ptask->dead = true;
+    // free that task straightly if it's a blocked task
+    if (ptask->state == BLOCKED) {
+        xizi_task_manager.free_pcb(ptask);
+    }
+    // yield current task in case it wants to exit itself
     xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
     return 0;
 }
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
index 5d9bef5c8..acfe6ffa1 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
@@ -35,7 +35,25 @@ extern int sys_exit(struct TaskMicroDescriptor* task);
 int sys_kill(int id)
 {
     struct TaskMicroDescriptor* task = NULL;
+    // check if task is a running one
+    DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_running_list_head, node)
+    {
+        if (task->pid == id) {
+            sys_exit(task);
+            return 0;
+        }
+    }
 
+    // check if task is a blocking one
+    DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_blocked_list_head, node)
+    {
+        if (task->pid == id) {
+            sys_exit(task);
+            return 0;
+        }
+    }
+
+    // check if task is a ready one
     for (int prio = 0; prio < TASK_MAX_PRIORITY; prio++) {
         DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_list_head[prio], node)
         {
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
index 04279fa77..63ad8e0de 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
@@ -140,8 +140,6 @@ int sys_unbind_irq(struct TaskMicroDescriptor* task, int irq_num)
     }
 
     irq_forward_table[irq_num].handle_task = NULL;
-    sys_close_session(kernel_irq_proxy, &irq_forward_table[irq_num].session);
-    DEBUG("Unbind: %s to irq %d", task->name, irq_num);
     return 0;
 }
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
index 01309cb22..68d15be79 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_state.c
@@ -66,6 +66,13 @@ void show_tasks(void)
     }
     LOG_PRINTF("******************************************************\n");
     LOG_PRINTF("STAT     ID   TASK            PRI   MEM(KB)\n");
+    DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_running_list_head, node)
+    {
+        LOG_PRINTF("RUNNING ");
+        _padding(task->name);
+        LOG_PRINTF("  %d   %s  %d       %d\n", task->pid, task->name, task->priority, task->mem_size >> 10);
+    }
+
     for (int i = 0; i < TASK_MAX_PRIORITY; i++) {
         if (IS_DOUBLE_LIST_EMPTY(&xizi_task_manager.task_list_head[i])) {
             continue;
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/schedule.c b/Ubiquitous/XiZi_AIoT/softkernel/task/schedule.c
index a19d6a50d..080828839 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/schedule.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/schedule.c
@@ -27,14 +27,18 @@ Author: AIIT XUOS Lab
 Modification:
 1. first version
 *************************************************/
+#include "log.h"
 #include "scheduler.h"
 
 struct TaskMicroDescriptor* max_priority_runnable_task(void)
 {
-    struct TaskMicroDescriptor* task = NULL;
-    uint32_t priority = 0;
+    static struct TaskMicroDescriptor* task = NULL;
+    static int priority = 0;
 
     priority = __builtin_ffs(ready_task_priority) - 1;
+    if (priority > 31 || priority < 0) {
+        return NULL;
+    }
 
     DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_list_head[priority], node)
     {
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
index 59a83cfda..cde613e67 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
@@ -42,6 +42,20 @@ Modification:
 struct CPU global_cpus[NR_CPU];
 uint32_t ready_task_priority;
 
+static inline void task_node_leave_list(struct TaskMicroDescriptor* task)
+{
+    doubleListDel(&task->node);
+    if (IS_DOUBLE_LIST_EMPTY(&xizi_task_manager.task_list_head[task->priority])) {
+        ready_task_priority &= ~((uint32_t)1 << task->priority);
+    }
+}
+
+static inline void task_node_add_to_ready_list(struct TaskMicroDescriptor* task)
+{
+    doubleListAddOnBack(&task->node, &xizi_task_manager.task_list_head[task->priority]);
+    ready_task_priority |= ((uint32_t)1 << task->priority);
+}
+
 static void _task_manager_init()
 {
     // init task list to NULL
@@ -49,6 +63,7 @@ static void _task_manager_init()
         doubleListNodeInit(&xizi_task_manager.task_list_head[i]);
     }
     doubleListNodeInit(&xizi_task_manager.task_blocked_list_head);
+    doubleListNodeInit(&xizi_task_manager.task_running_list_head);
     // init task (slab) allocator
     slab_init(&xizi_task_manager.task_allocator, sizeof(struct TaskMicroDescriptor));
     slab_init(&xizi_task_manager.task_buddy_allocator, sizeof(struct KBuddy));
@@ -148,9 +163,8 @@ static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
         kfree((char*)task->main_thread.stack_addr);
     }
 
-    struct double_list_node* cur_node = &task->node;
     // remove it from used task list
-    doubleListDel(cur_node);
+    task_node_leave_list(task);
 
     // free task back to allocator
     if (task->massive_ipc_allocator != NULL) {
@@ -158,11 +172,6 @@ static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
         slab_free(&xizi_task_manager.task_buddy_allocator, (void*)task->massive_ipc_allocator);
     }
     slab_free(&xizi_task_manager.task_allocator, (void*)task);
-
-    // remove priority
-    if (IS_DOUBLE_LIST_EMPTY(&xizi_task_manager.task_list_head[task->priority])) {
-        ready_task_priority &= ~(1 << task->priority);
-    }
 }
 
 /* alloc a new task with init */
@@ -217,8 +226,15 @@ static void _task_set_default_schedule_attr(struct TaskMicroDescriptor* task)
     task->maxium_tick = TASK_CLOCK_TICK * 10;
     task->state = READY;
     task->priority = TASK_DEFAULT_PRIORITY;
-    doubleListAddOnHead(&task->node, &xizi_task_manager.task_list_head[task->priority]);
-    ready_task_priority |= (1 << task->priority);
+    task_node_add_to_ready_list(task);
+}
+
+static void task_state_set_running(struct TaskMicroDescriptor* task)
+{
+    assert(task != NULL && task->state == READY);
+    task->state = RUNNING;
+    task_node_leave_list(task);
+    doubleListAddOnHead(&task->node, &xizi_task_manager.task_running_list_head);
 }
 
 struct TaskMicroDescriptor* next_task_emergency = NULL;
@@ -249,8 +265,7 @@ static void _scheduler(struct SchedulerRightGroup right_group)
         }
 
         /* run the chosen task */
-        assert(next_task->state == READY);
-        next_task->state = RUNNING;
+        task_state_set_running(next_task);
         cpu->task = next_task;
         p_mmu_driver->LoadPgdir((uintptr_t)V2P(next_task->pgdir.pd_addr));
         context_switch(&cpu->scheduler, next_task->main_thread.context);
@@ -261,27 +276,23 @@ static void _scheduler(struct SchedulerRightGroup right_group)
 static void _task_yield_noschedule(struct TaskMicroDescriptor* task, bool blocking)
 {
     assert(task != NULL);
+    /// @warning only support current task yield now
+    assert(task == cur_cpu()->task && task->state == RUNNING);
 
     // rearrage current task position
-    doubleListDel(&task->node);
+    task_node_leave_list(task);
     if (task->state == RUNNING) {
         task->state = READY;
     }
     task->remain_tick = TASK_CLOCK_TICK;
-    if (task == cur_cpu()->task) {
-        cur_cpu()->task = NULL;
-    }
-    doubleListAddOnBack(&task->node, &xizi_task_manager.task_list_head[task->priority]);
+    task_node_add_to_ready_list(task);
 }
 
 static void _task_block(struct TaskMicroDescriptor* task)
 {
     assert(task != NULL);
     assert(task->state != RUNNING);
-    doubleListDel(&task->node);
-    if (xizi_task_manager.task_list_head[task->priority].next == &xizi_task_manager.task_list_head[task->priority]) {
-        ready_task_priority &= ~(1 << task->priority);
-    }
+    task_node_leave_list(task);
     task->state = BLOCKED;
     doubleListAddOnHead(&task->node, &xizi_task_manager.task_blocked_list_head);
 }
@@ -290,12 +301,13 @@ static void _task_unblock(struct TaskMicroDescriptor* task)
 {
     assert(task != NULL);
     assert(task->state == BLOCKED);
-    doubleListDel(&task->node);
+    task_node_leave_list(task);
     task->state = READY;
-    doubleListAddOnHead(&task->node, &xizi_task_manager.task_list_head[task->priority]);
-    ready_task_priority |= (1 << task->priority);
+    task_node_add_to_ready_list(task);
 }
 
+/// @brief  @warning not tested function
+/// @param priority
 static void _set_cur_task_priority(int priority)
 {
     if (priority < 0 || priority >= TASK_MAX_PRIORITY) {
@@ -304,14 +316,13 @@ static void _set_cur_task_priority(int priority)
     }
 
     struct TaskMicroDescriptor* current_task = cur_cpu()->task;
-    assert(current_task != NULL);
+    assert(current_task != NULL && current_task->state == RUNNING);
+
+    task_node_leave_list(current_task);
 
     current_task->priority = priority;
 
-    doubleListDel(&current_task->node);
-    doubleListAddOnBack(&current_task->node, &xizi_task_manager.task_list_head[current_task->priority]);
-
-    ready_task_priority |= (1 << current_task->priority);
+    task_node_add_to_ready_list(current_task);
 
     return;
 }