diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
index 11043cb7c..f8af8ccc9 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/core.h
@@ -74,7 +74,7 @@ Modification:
 
 #include "cortex_a9.h"
 
-#define NR_CPU 4
+#define NR_CPU 3
 
 __attribute__((always_inline)) static inline uint32_t user_mode()
 {
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/hardkernel_init.c b/Ubiquitous/XiZi_AIoT/hardkernel/hardkernel_init.c
index 660b883f9..351a1266f 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/hardkernel_init.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/hardkernel_init.c
@@ -218,10 +218,7 @@ bool secondary_cpu_hardkernel_init(int cpu_id, struct TraceTag* _hardkernel_tag)
     // cache
     p_icache_driver->enable();
     p_dcache_driver->enable();
-    // p_icache_driver->disable();
-    // p_dcache_driver->disable();
     // clock
-    // p_clock_driver->sys_clock_init();
     p_intr_driver->single_irq_enable(p_clock_driver->get_clock_int(), cpu_id, 0);
     // mmu
     secondary_cpu_load_kern_pgdir(&init_mmu_tag, &init_intr_tag);
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/test_irq_sender.c b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/test_irq_sender.c
index cd0cc4262..223b1f4d8 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/test_irq_sender.c
+++ b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/test_irq_sender.c
@@ -24,6 +24,19 @@ enum {
     ARM_PERIPHERAL_VIRT_BASE = 0x50000000,
 };
 
+enum _gicd_sgi_filter {
+    //! Forward the interrupt to the CPU interfaces specified in the @a target_list parameter.
+    kGicSgiFilter_UseTargetList = 0,
+
+    //! Forward the interrupt to all CPU interfaces except that of the processor that requested
+    //! the interrupt.
+    kGicSgiFilter_AllOtherCPUs = 1,
+
+    //! Forward the interrupt only to the CPU interface of the processor that requested the
+    //! interrupt.
+    kGicSgiFilter_OnlyThisCPU = 2
+};
+
 struct _gicd_registers {
     uint32_t CTLR; //!< Distributor Control Register.
     uint32_t TYPER; //!< Interrupt Controller Type Register.
@@ -76,7 +89,7 @@ int main()
     mmap(ARM_PERIPHERAL_VIRT_BASE, ARM_PERIPHERAL_BASE, 0x2000, true);
 
     printf("%s: Sending soft interrupt\n", prog_name);
-    gic_send_sgi(SW_INTERRUPT_3, 0, 2);
+    gic_send_sgi(SW_INTERRUPT_3, 0, kGicSgiFilter_OnlyThisCPU);
     printf("%s: Soft interrupt send done\n", prog_name);
     exit();
 }
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.c b/Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.c
index 0d9582aae..410048c31 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.c
+++ b/Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.c
@@ -178,24 +178,29 @@ void ipc_server_loop(struct IpcNode* ipc_node)
                 a session could be delay in case one of its message(current message) needs to wait for an interrupt message's arrival
                 interfaces[opcode] should explicitly call delay_session() and return to delay this session
             */
-            while (msg->header.magic == IPC_MSG_MAGIC && msg->header.valid == 1 && msg->header.done != 1) {
+            while (msg->header.magic == IPC_MSG_MAGIC && msg->header.valid == 1) {
                 // printf("session %d [%d, %d]\n", session_list[i].id, session_list[i].head, session_list[i].tail);
                 if (session_used_size(&session_list[i]) == 0 && session_forward_tail(&session_list[i], msg->header.len) < 0) {
                     break;
                 }
-                if (ipc_node->interfaces[msg->header.opcode]) {
-                    ipc_node->interfaces[msg->header.opcode](msg);
-                    // check if this session is delayed by op handler, all messages after the delayed message in current session is blocked.
-                    if (session_delayed) {
-                        session_delayed = false;
-                        break;
+
+                // this is a message needs to handle
+                if (msg->header.done != 1) {
+                    if (ipc_node->interfaces[msg->header.opcode]) {
+                        ipc_node->interfaces[msg->header.opcode](msg);
+                        // check if this session is delayed by op handler, all messages after the delayed message in current session is blocked.
+                        if (session_delayed) {
+                            session_delayed = false;
+                            break;
+                        }
+                    } else {
+                        printf("Unsupport opcode(%d) for server: %s\n", msg->header.opcode, ipc_node->name);
                     }
-                } else {
-                    printf("Unsupport opcode(%d) for server: %s\n", msg->header.opcode, ipc_node->name);
                 }
+                // current msg is a message that needs to ignore
                 // finish this message in server's perspective
-                while (session_forward_head(&session_list[i], msg->header.len) < 0) {
-                    yield();
+                if (session_forward_head(&session_list[i], msg->header.len) < 0) {
+                    break;
                 }
                 msg = IPCSESSION_MSG(&session_list[i]);
             }
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.c b/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.c
index 27e88c706..a399dec18 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.c
+++ b/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.c
@@ -61,6 +61,6 @@ bool session_free_buf(struct Session* session, int len)
     if (len > session_used_size(session)) {
         return false;
     }
-    assert(session_forward_head(session, len) != 1);
+    assert(session_forward_head(session, len) != -1);
     return true;
 }
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.h b/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.h
index 24952db0c..4979f74ca 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.h
+++ b/Ubiquitous/XiZi_AIoT/services/lib/ipc/session.h
@@ -55,7 +55,7 @@ __attribute__((__always_inline__)) static inline int session_remain_capacity(str
 
 __attribute__((__always_inline__)) static inline int session_forward_head(struct Session* session, int len)
 {
-    if (((session->head + len) % session->capacity) > session->tail) {
+    if (len > session_used_size(session)) {
         printf("forward head with too much size\n");
         return -1;
     }
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
index fa9263196..726e4f518 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/task.h
@@ -48,6 +48,7 @@ enum ProcState {
     READY,
     RUNNING,
     DEAD,
+    BLOCKED,
     NEVER_RUN,
 };
 
@@ -118,7 +119,7 @@ struct XiziTaskManager {
     /* function that's runing by kernel thread context, schedule use tasks */
     void (*task_scheduler)(struct SchedulerRightGroup);
     /* call to yield current use task */
-    void (*cur_task_yield_noschedule)(void);
+    void (*task_yield_noschedule)(struct TaskMicroDescriptor* task, bool is_blocking);
     /* set task priority */
     void (*set_cur_task_priority)(int priority);
 };
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/main.c b/Ubiquitous/XiZi_AIoT/softkernel/main.c
index a3de7b8aa..e79beecaf 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/main.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/main.c
@@ -90,13 +90,14 @@ int main(void)
     struct SchedulerRightGroup scheduler_rights;
     assert(AchieveResourceTag(&scheduler_rights.mmu_driver_tag, &hardkernel_tag, "mmu-ac-resource"));
     assert(AchieveResourceTag(&scheduler_rights.intr_driver_tag, &hardkernel_tag, "intr-ac-resource"));
-
     core_init_done |= (1 << cpu_id);
     LOG_PRINTF("CPU %d init done\n", cpu_id);
     spinlock_unlock(&whole_kernel_lock);
 
     while (core_init_done != (1 << NR_CPU) - 1)
         ;
+
+    xizi_enter_kernel();
     start_smp_cache_broadcast(cpu_id);
     xizi_task_manager.task_scheduler(scheduler_rights);
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
index bd5a99612..25ebadc11 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_exit.c
@@ -82,7 +82,7 @@ int sys_exit(struct TaskMicroDescriptor* ptask)
     }
 
     // delete task for pcb_list
-    xizi_task_manager.cur_task_yield_noschedule();
+    xizi_task_manager.task_yield_noschedule(ptask, true);
     ptask->state = DEAD;
 
     return 0;
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
index 0a953892a..5b0722070 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
@@ -84,7 +84,7 @@ int user_irq_handler(int irq, void* tf, void* arg)
     p_mmu_driver->LoadPgdir((uintptr_t)V2P(cur_cpu()->task->pgdir.pd_addr));
 
     next_task_emergency = irq_forward_table[irq].handle_task;
-    xizi_task_manager.cur_task_yield_noschedule();
+    xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
     return 0;
 }
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_yield.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_yield.c
index 6aa426047..f4dc7b868 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_yield.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_yield.c
@@ -35,6 +35,6 @@ Modification:
 
 int sys_yield()
 {
-    xizi_task_manager.cur_task_yield_noschedule();
+    xizi_task_manager.task_yield_noschedule(cur_cpu()->task, false);
     return 0;
 }
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c b/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
index a8d8048dd..f693ab871 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/scheduler.c
@@ -40,7 +40,6 @@ struct TaskMicroDescriptor* max_priority_runnable_task(void)
     {
         if (task->state == READY) {
             // found a runnable task, stop this look up
-            task->state = RUNNING;
             return task;
         } else if (task->state == DEAD) {
             // found a killed task, stop this loop
@@ -61,7 +60,6 @@ struct TaskMicroDescriptor* round_robin_runnable_task(uint32_t priority)
 
         if (task->state == READY) {
             // found a runnable task, stop this look up
-            task->state = RUNNING;
             return task;
         } else if (task->state == DEAD) {
             // found a killed task, stop this loop
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
index 941f19d63..8e8898c3b 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
@@ -171,7 +171,6 @@ struct TaskMicroDescriptor* next_task_emergency = NULL;
 extern void context_switch(struct context**, struct context*);
 static void _scheduler(struct SchedulerRightGroup right_group)
 {
-    xizi_enter_kernel();
     struct MmuCommonDone* p_mmu_driver = AchieveResource(&right_group.mmu_driver_tag);
     struct TaskMicroDescriptor* next_task;
 
@@ -182,20 +181,25 @@ static void _scheduler(struct SchedulerRightGroup right_group)
         if (next_task_emergency != NULL && next_task->state == READY) {
             next_task = next_task_emergency;
             next_task->state = RUNNING;
-            next_task_emergency = NULL;
         } else {
             next_task = xizi_task_manager.next_runnable_task();
         }
+        next_task_emergency = NULL;
+        if (next_task != NULL) {
+            assert(next_task->state == READY);
+            next_task->state = RUNNING;
+        }
         spinlock_unlock(&whole_kernel_lock);
 
         /* not a runnable task */
-        if (UNLIKELY(next_task == NULL) || UNLIKELY(next_task->state != RUNNING)) {
+        if (UNLIKELY(next_task == NULL)) {
             spinlock_lock(&whole_kernel_lock);
             continue;
         }
 
         /* a runnable task */
         spinlock_lock(&whole_kernel_lock);
+        assert(next_task->state == RUNNING);
         struct CPU* cpu = cur_cpu();
         cpu->task = next_task;
         p_mmu_driver->LoadPgdir((uintptr_t)V2P(next_task->pgdir.pd_addr));
@@ -203,34 +207,24 @@ static void _scheduler(struct SchedulerRightGroup right_group)
     }
 }
 
-static uint32_t yield_cnt = 0;
-static void _cur_task_yield_noschedule(void)
+static void _task_yield_noschedule(struct TaskMicroDescriptor* task, bool blocking)
 {
-    yield_cnt++;
-
-    struct TaskMicroDescriptor* current_task = cur_cpu()->task;
-    assert(current_task != NULL);
+    assert(task != NULL);
 
     // rearrage current task position
-    doubleListDel(&current_task->node);
-    // DEBUG("%s,%d\n", current_task->name, strcmp(current_task->name, name1));
-    if (current_task->maxium_tick <= 0) {
-        if (IS_DOUBLE_LIST_EMPTY(&xizi_task_manager.task_list_head[current_task->priority])) {
-            ready_task_priority &= ~(1 << current_task->priority);
+    doubleListDel(&task->node);
+    if (task->state == RUNNING) {
+        if (!blocking) {
+            task->state = READY;
+        } else {
+            task->state = BLOCKED;
         }
-        current_task->priority += 1;
-        current_task->maxium_tick = TASK_CLOCK_TICK * 10;
     }
-    doubleListAddOnBack(&current_task->node, &xizi_task_manager.task_list_head[current_task->priority]);
-    ready_task_priority |= (1 << current_task->priority);
-    // set current task state
-    current_task->state = READY;
-    current_task->remain_tick = TASK_CLOCK_TICK;
-    cur_cpu()->task = NULL;
-    if (yield_cnt == 50) {
-        recover_priority();
-        yield_cnt = 0;
+    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]);
 }
 
 static void _set_cur_task_priority(int priority)
@@ -261,7 +255,7 @@ struct XiziTaskManager xizi_task_manager = {
 
     .next_runnable_task = max_priority_runnable_task,
     .task_scheduler = _scheduler,
-    .cur_task_yield_noschedule = _cur_task_yield_noschedule,
+    .task_yield_noschedule = _task_yield_noschedule,
     .set_cur_task_priority = _set_cur_task_priority
 };
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
index b3453dd2c..6c4c92915 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/clock_irq_handler.c
@@ -58,7 +58,7 @@ int xizi_clock_handler(int irq, void* tf, void* arg)
             current_task->remain_tick--;
             current_task->maxium_tick--;
             if (current_task->remain_tick == 0) {
-                xizi_task_manager.cur_task_yield_noschedule();
+                xizi_task_manager.task_yield_noschedule(current_task, false);
             }
         }
     }