diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/context_switch.S b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/context_switch.S
index ae0620e2f..9e52ccda4 100755
--- a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/context_switch.S
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/context_switch.S
@@ -31,32 +31,14 @@ Modification:
 
 context_switch:
 	# store original context to stack
-	str lr, [r13, #-4]!
-	str r12, [r13, #-4]!
-	str r11, [r13, #-4]!
-	str r10, [r13, #-4]!
-	str r9, [r13, #-4]!
-	str r8, [r13, #-4]!
-	str r7, [r13, #-4]!
-	str r6, [r13, #-4]!
-	str r5, [r13, #-4]!
-	str r4, [r13, #-4]!
+	stmfd   r13!, 	{r4-r12, lr}
 
 	# switch the stack
 	str     r13, 	[r0]          	// save current sp to the old PCB (**old)
 	mov     r13, 	r1            	// load the next stack
 
 	# restore context from stack
-	ldr r4, [r13], #4
-	ldr r5, [r13], #4
-	ldr r6, [r13], #4
-	ldr r7, [r13], #4
-	ldr r8, [r13], #4
-	ldr r9, [r13], #4
-	ldr r10, [r13], #4
-	ldr r11, [r13], #4
-	ldr r12, [r13], #4
-	ldr lr, [r13], #4
+	ldmfd   r13!, 	{r4-r12, lr} 
 
 	# return to the caller
 	bx      lr
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..4f7dd53a1 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
@@ -76,7 +76,7 @@ Modification:
 
 #define NR_CPU 4
 
-__attribute__((always_inline)) static inline uint32_t user_mode()
+__attribute__((always_inline, optimize("O0"))) static inline uint32_t user_mode()
 {
     uint32_t val;
 
@@ -103,12 +103,12 @@ struct context {
     uint32_t r11;
     uint32_t r12;
     uint32_t lr;
-};
+} __attribute__((packed));
 
 /// @brief init task context, set return address to trap return
 /// @param
 extern void task_prepare_enter();
-__attribute__((__always_inline__)) static inline void arch_init_context(struct context* ctx)
+__attribute__((always_inline, optimize("O0"))) static inline void arch_init_context(struct context* ctx)
 {
     memset(ctx, 0, sizeof(*ctx));
     ctx->lr = (uint32_t)(task_prepare_enter + 4);
@@ -133,13 +133,13 @@ struct trapframe {
     uint32_t r11;
     uint32_t r12;
     uint32_t pc;
-};
+} __attribute__((packed));
 
 /// @brief init task trapframe (*especially the user mode cpsr)
 /// @param tf
 /// @param sp
 /// @param pc
-__attribute__((__always_inline__)) static inline void arch_init_trapframe(struct trapframe* tf, uintptr_t sp, uintptr_t pc)
+__attribute__((always_inline, optimize("O0"))) static inline void arch_init_trapframe(struct trapframe* tf, uintptr_t sp, uintptr_t pc)
 {
     memset(tf, 0, sizeof(*tf));
     tf->spsr = user_mode();
@@ -153,7 +153,7 @@ __attribute__((__always_inline__)) static inline void arch_init_trapframe(struct
 /// @param tf
 /// @param sp
 /// @param pc
-__attribute__((__always_inline__)) static inline void arch_trapframe_set_sp_pc(struct trapframe* tf, uintptr_t sp, uintptr_t pc)
+__attribute__((always_inline, optimize("O0"))) static inline void arch_trapframe_set_sp_pc(struct trapframe* tf, uintptr_t sp, uintptr_t pc)
 {
     tf->sp_usr = sp;
     tf->pc = pc;
@@ -163,7 +163,7 @@ __attribute__((__always_inline__)) static inline void arch_trapframe_set_sp_pc(s
 /// @param tf
 /// @param argc
 /// @param argv
-__attribute__((__always_inline__)) static inline void arch_set_main_params(struct trapframe* tf, int argc, uintptr_t argv)
+__attribute__((always_inline, optimize("O0"))) static inline void arch_set_main_params(struct trapframe* tf, int argc, uintptr_t argv)
 {
     tf->r0 = (uint32_t)argc;
     tf->r1 = (uint32_t)argv;
@@ -178,7 +178,7 @@ __attribute__((__always_inline__)) static inline void arch_set_main_params(struc
 /// @param param5
 /// @return
 extern int syscall(int sys_num, uintptr_t param1, uintptr_t param2, uintptr_t param3, uintptr_t param4);
-__attribute__((__always_inline__)) static inline int arch_syscall(struct trapframe* tf, int* syscall_num)
+__attribute__((always_inline, optimize("O0"))) static inline int arch_syscall(struct trapframe* tf, int* syscall_num)
 {
     // call syscall
     *syscall_num = tf->r0;
@@ -188,7 +188,7 @@ __attribute__((__always_inline__)) static inline int arch_syscall(struct trapfra
 /// @brief set return reg to trapframe
 /// @param tf
 /// @param ret
-__attribute__((__always_inline__)) static inline void arch_set_return(struct trapframe* tf, int ret)
+__attribute__((always_inline, optimize("O0"))) static inline void arch_set_return(struct trapframe* tf, int ret)
 {
     tf->r0 = (uint32_t)ret;
 }
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/gicv2/gicv2_distributer_to_device.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/gicv2/gicv2_distributer_to_device.c
index 94c4b12f0..95b9d8f09 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/gicv2/gicv2_distributer_to_device.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/gicv2/gicv2_distributer_to_device.c
@@ -45,6 +45,8 @@ Author: AIIT XUOS Lab
 Modification:
 1. take only gicd part of functions
 *************************************************/
+#include "string.h"
+
 #include "gicv2_common_opa.h"
 #include "gicv2_registers.h"
 
@@ -139,7 +141,7 @@ void gic_send_sgi(uint32_t irqID, uint32_t target_list, uint32_t filter_list)
 
 void gic_init(void)
 {
-    gicd_t* gicd = gic_get_gicd();
+    volatile gicd_t* gicd = gic_get_gicd();
 
     // First disable the distributor.
     gic_enable(false);
@@ -150,7 +152,9 @@ void gic_init(void)
 
     for (uint32_t i = 0; i < 255; i++) {
         *(uint32_t*)(&gicd->IPRIORITYRn[i * sizeof(uint32_t)]) = (uint32_t)0x80808080;
+        // memset((void*)&gicd->IPRIORITYRn[i * sizeof(uint32_t)], 0x80, sizeof(uint32_t));
         *(uint32_t*)(&gicd->ITARGETSRn[i * sizeof(uint32_t)]) = (uint32_t)0x01010101;
+        // memset((void*)&gicd->IPRIORITYRn[i * sizeof(uint32_t)], 0x01, sizeof(uint32_t));
     }
 
     // Init the GIC CPU interface.
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/spinlock.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/spinlock.c
index 9e1014316..245a44fca 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/spinlock.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/spinlock.c
@@ -52,7 +52,7 @@ enum {
     SPINLOCK_LOCK_WAITFOREVER = 0xFFFFFFFF,
 };
 
-void spinlock_init(struct spinlock* lock, char* name)
+__attribute__((optimize("O0"))) void spinlock_init(struct spinlock* lock, char* name)
 {
     lock->owner_cpu = SPINLOCK_STATE_UNLOCK;
     strncpy(lock->name, name, 24);
@@ -61,7 +61,7 @@ void spinlock_init(struct spinlock* lock, char* name)
 extern int _spinlock_lock(struct spinlock* lock, uint32_t timeout);
 void _spinlock_unlock(struct spinlock* lock);
 
-void spinlock_lock(struct spinlock* lock)
+__attribute__((optimize("O0"))) void spinlock_lock(struct spinlock* lock)
 {
     int cur_cpu_id = cur_cpuid();
     if (lock->owner_cpu != SPINLOCK_STATE_UNLOCK && lock->owner_cpu == cur_cpu_id) {
@@ -80,7 +80,7 @@ void spinlock_lock(struct spinlock* lock)
     _spinlock_lock(lock, SPINLOCK_LOCK_WAITFOREVER);
 }
 
-void spinlock_unlock(struct spinlock* lock)
+__attribute__((optimize("O0"))) void spinlock_unlock(struct spinlock* lock)
 {
     struct double_list_node* p_lock_node = &core_lock_request[cur_cpuid()].node;
     assert(lock_request_guard.next == p_lock_node);
@@ -91,7 +91,7 @@ void spinlock_unlock(struct spinlock* lock)
     _spinlock_unlock(lock);
 }
 
-bool spinlock_try_lock(struct spinlock* lock)
+__attribute__((optimize("O0"))) bool spinlock_try_lock(struct spinlock* lock)
 {
     int cur_cpu_id = cur_cpuid();
     if (lock->owner_cpu != SPINLOCK_STATE_UNLOCK && lock->owner_cpu == cur_cpu_id) {
diff --git a/Ubiquitous/XiZi_AIoT/kernel_actracer/actracer.c b/Ubiquitous/XiZi_AIoT/kernel_actracer/actracer.c
index c0a259dee..7d9a6a6ac 100644
--- a/Ubiquitous/XiZi_AIoT/kernel_actracer/actracer.c
+++ b/Ubiquitous/XiZi_AIoT/kernel_actracer/actracer.c
@@ -101,7 +101,7 @@ static bool dealloc_trace_meta(struct TraceMeta* meta)
 
 static tracer_mem_chunk_idx_t trace_meta_map_mem_chunk(struct TraceMeta* const p_trace_meta, tracer_mem_chunk_idx_t mem_chunk_num)
 {
-    tracer_mem_chunk_idx_t addr;
+    tracer_mem_chunk_idx_t addr = 0;
     /* direct mapping */
     if (mem_chunk_num < TRACEMETA_NR_DIRECT) {
         if ((addr = p_trace_meta->addr[mem_chunk_num]) == 0) {
diff --git a/Ubiquitous/XiZi_AIoT/services/app/Makefile b/Ubiquitous/XiZi_AIoT/services/app/Makefile
index ebf29d76e..69b548d0e 100644
--- a/Ubiquitous/XiZi_AIoT/services/app/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/app/Makefile
@@ -24,9 +24,9 @@ INC_DIR = 	-I$(KERNEL_ROOT)/services/shell/letter-shell \
 			-I$(KERNEL_ROOT)/services/app 
 
 ifeq ($(BOARD), imx6q-sabrelite)
-all: init test_fs simple_client simple_server shell fs_server test_priority test_irq_hdlr test_irq_send readme.txt | bin
+all: init test_fs simple_client simple_server shell fs_server test_irq_hdlr test_irq_send readme.txt | bin
 else 
-all: init test_fs simple_client simple_server shell fs_server test_priority test_irq_hdlr readme.txt | bin
+all: init test_fs simple_client simple_server shell fs_server test_irq_hdlr readme.txt | bin
 endif
 	../tools/mkfs/mkfs ./fs.img $^
 	@mv $(filter-out readme.txt, $^) bin
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 21e4a2fef..c3eb4328f 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
@@ -88,7 +88,8 @@ int main()
     printf("%s: Mapping GIC\n", prog_name);
     mmap(ARM_PERIPHERAL_VIRT_BASE, ARM_PERIPHERAL_BASE, 0x2000, true);
 
-    int send_time = 1000;
+    // int send_time = 1000;
+    int send_time = 1;
     printf("%s: Sending soft interrupt for %d times\n", prog_name, send_time);
     for (int i = 0; i < send_time; i++) {
         gic_send_sgi(SW_INTERRUPT_3, 0xF, kGicSgiFilter_UseTargetList);
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h b/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
index d0e950565..2bf28ceb0 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/multicores.h
@@ -47,7 +47,7 @@ static inline struct CPU* cur_cpu(void)
     return &global_cpus[cur_cpuid()];
 }
 
-struct spinlock whole_kernel_lock;
+extern struct spinlock whole_kernel_lock;
 
 void xizi_enter_kernel();
 bool xizi_try_enter_kernel();
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
index 052cfff9f..4e99da1a8 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/syscall.h
@@ -92,7 +92,7 @@ int sys_kill(int id);
 int sys_register_as_server(char* name);
 int sys_connect_session(char* path, int capacity, struct Session* user_session);
 int sys_poll_session(struct Session* userland_session_arr, int arr_capacity);
-int sys_close_session(struct Session* session);
+int sys_close_session(struct TaskMicroDescriptor* task, struct Session* session);
 
 int sys_exec(char* img_start, char* name, char** argv);
 int sys_state(sys_state_option option, sys_state_info* info);
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/main.c b/Ubiquitous/XiZi_AIoT/softkernel/main.c
index e79beecaf..df9ad7228 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/main.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/main.c
@@ -35,12 +35,14 @@ Modification:
 #include "assert.h"
 #include "task.h"
 
+struct spinlock whole_kernel_lock;
+
 extern uint32_t _binary_init_start[], _binary_default_fs_start[];
 extern int sys_spawn(char* img_start, char* name, char** argv);
 
 static struct TraceTag hardkernel_tag, softkernel_tag;
-static int core_init_done = 0;
-int main(void)
+static volatile int core_init_done = 0;
+__attribute__((optimize("O0"))) int main(void)
 {
     /* init tracer */
     uint32_t cpu_id = cur_cpuid();
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c b/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
index a2a054119..d73cb3102 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
@@ -294,11 +294,9 @@ void load_kern_pgdir(struct TraceTag* mmu_driver_tag, struct TraceTag* intr_driv
     _map_pages((uintptr_t*)kern_pgdir.pd_addr, DEV_VRTMEM_BASE, DEV_PHYMEM_BASE, DEV_MEM_SZ, dev_attr);
 
     _p_pgtbl_mmu_access->LoadPgdir((uintptr_t)V2P(kern_pgdir.pd_addr));
-    // _p_pgtbl_mmu_access->LoadPgdirCrit((uintptr_t)V2P(kern_pgdir.pd_addr), intr_driver_tag);
 }
 
 void secondary_cpu_load_kern_pgdir(struct TraceTag* mmu_driver_tag, struct TraceTag* intr_driver_tag)
 {
     _p_pgtbl_mmu_access->LoadPgdir((uintptr_t)V2P(kern_pgdir.pd_addr));
-    // _p_pgtbl_mmu_access->LoadPgdirCrit((uintptr_t)V2P(kern_pgdir.pd_addr), intr_driver_tag);
 }
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_close_session.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_close_session.c
index e87f1bcfd..3299f24bf 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_close_session.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_close_session.c
@@ -33,9 +33,8 @@ Modification:
 #include "syscall.h"
 #include "task.h"
 
-int sys_close_session(struct Session* session)
+int sys_close_session(struct TaskMicroDescriptor* cur_task, struct Session* session)
 {
-    struct TaskMicroDescriptor* cur_task = cur_cpu()->task;
     assert(cur_task != NULL);
     /* check if session is available */
     if (session->buf == NULL || (uintptr_t)session->buf < USER_IPC_SPACE_BASE || (uintptr_t)session->buf > USER_IPC_SPACE_TOP) {
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
index e7e0eb8cc..04279fa77 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_register_irq.c
@@ -35,7 +35,6 @@ Modification:
 #include "assert.h"
 #include "ipc.h"
 #include "kalloc.h"
-#include "mmu_common.h"
 #include "multicores.h"
 #include "share_page.h"
 #include "syscall.h"
@@ -51,33 +50,35 @@ static struct {
 
 static void send_irq_to_user(int irq_num)
 {
-    struct Session* session = &irq_forward_table[irq_num].session;
-    int len = IPC_ARG_INFO_BASE_OFFSET;
-    len += sizeof(struct IpcArgInfo);
+    if (irq_forward_table[irq_num].handle_task != NULL) {
+        struct Session* session = &irq_forward_table[irq_num].session;
+        int len = IPC_ARG_INFO_BASE_OFFSET;
+        len += sizeof(struct IpcArgInfo);
 
-    /* get message space and add session tail */
-    void* session_kern_vaddr = P2V(xizi_pager.address_translate(&kernel_irq_proxy->pgdir, (uintptr_t)session->buf));
-    struct IpcMsg* buf = session_kern_vaddr + session->tail;
+        /* get message space and add session tail */
+        void* session_kern_vaddr = P2V(xizi_pager.address_translate(&kernel_irq_proxy->pgdir, (uintptr_t)session->buf));
+        struct IpcMsg* buf = session_kern_vaddr + session->tail;
 
-    /* check if server session is full */
-    if (buf->header.magic == IPC_MSG_MAGIC && buf->header.done == 0) {
-        DEBUG("irq server cannot handle new interrupt by now.\n");
-        return;
+        /* check if server session is full */
+        if (buf->header.magic == IPC_MSG_MAGIC && buf->header.done == 0) {
+            DEBUG("irq server cannot handle new interrupt by now.\n");
+            return;
+        }
+        memset((void*)buf, 0, len);
+        session->tail = (session->tail + len) % session->capacity;
+
+        /* construct message */
+        buf->header.len = len;
+        buf->header.nr_args = 1;
+        buf->header.init = 1;
+        buf->header.opcode = irq_forward_table[irq_num].opcode;
+        buf->header.done = 0;
+        buf->header.magic = IPC_MSG_MAGIC;
+        buf->header.valid = 1;
+
+        /* add session head */
+        session->head = (session->head + len) % session->capacity;
     }
-    memset((void*)buf, 0, len);
-    session->tail = (session->tail + len) % session->capacity;
-
-    /* construct message */
-    buf->header.len = len;
-    buf->header.nr_args = 1;
-    buf->header.init = 1;
-    buf->header.opcode = irq_forward_table[irq_num].opcode;
-    buf->header.done = 0;
-    buf->header.magic = IPC_MSG_MAGIC;
-    buf->header.valid = 1;
-
-    /* add session head */
-    session->head = (session->head + len) % session->capacity;
 }
 
 int user_irq_handler(int irq, void* tf, void* arg)
@@ -118,7 +119,7 @@ int sys_register_irq(int irq_num, int irq_opcode)
     }
 
     // bind irq to session
-    if (p_intr_driver->sw_irqtbl[irq_num].handler != NULL) {
+    if (irq_forward_table[irq_num].handle_task != NULL) {
         ERROR("irq %d is occupied.\n", irq_num);
         return -1;
     }
@@ -139,7 +140,7 @@ int sys_unbind_irq(struct TaskMicroDescriptor* task, int irq_num)
     }
 
     irq_forward_table[irq_num].handle_task = NULL;
-    sys_close_session(&irq_forward_table[irq_num].session);
+    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/syscall.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
index 2a4a29248..c93532d77 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/syscall.c
@@ -60,7 +60,7 @@ int syscall(int sys_num, uintptr_t param1, uintptr_t param2, uintptr_t param3, u
         ret = sys_poll_session((struct Session*)param1, (int)param2);
         break;
     case SYSCALL_CLOSE_SESSION:
-        ret = sys_close_session((struct Session*)param1);
+        ret = sys_close_session(cur_cpu()->task, (struct Session*)param1);
         break;
     case SYSCALL_EXEC:
         ret = sys_exec((char*)param1, (char*)param2, (char**)param3);
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
index b7133e3fe..76b3fe9d3 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/task/task.c
@@ -167,7 +167,7 @@ static void _dealloc_task_cb(struct TaskMicroDescriptor* task)
 
 /* alloc a new task with init */
 extern void trap_return(void);
-void task_prepare_enter()
+__attribute__((optimize("O0"))) void task_prepare_enter()
 {
     xizi_leave_kernel();
     trap_return();
@@ -227,6 +227,7 @@ static void _scheduler(struct SchedulerRightGroup right_group)
 {
     struct MmuCommonDone* p_mmu_driver = AchieveResource(&right_group.mmu_driver_tag);
     struct TaskMicroDescriptor* next_task;
+    struct CPU* cpu = cur_cpu();
 
     while (1) {
         next_task = NULL;
@@ -238,29 +239,21 @@ static void _scheduler(struct SchedulerRightGroup right_group)
             next_task = xizi_task_manager.next_runnable_task();
         }
         next_task_emergency = NULL;
-        if (next_task != NULL) {
-            assert(next_task->state == READY);
-        }
-        spinlock_unlock(&whole_kernel_lock);
 
-        /* not a runnable task */
-        if (UNLIKELY(next_task == NULL)) {
-            spinlock_lock(&whole_kernel_lock);
+        /* if there's not a runnable task, wait for one */
+        if (next_task == NULL) {
+            xizi_leave_kernel();
+            /* leave kernel for other cores, so they may create a runnable task */
+            xizi_enter_kernel();
             continue;
         }
 
-        /* a runnable task */
-        spinlock_lock(&whole_kernel_lock);
-        if (next_task->state == READY) {
-            next_task->state = RUNNING;
-        } else {
-            continue;
-        }
-        struct CPU* cpu = cur_cpu();
+        /* run the chosen task */
+        assert(next_task->state == READY);
+        next_task->state = RUNNING;
         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);
-        assert(cur_cpu()->task == NULL);
         assert(next_task->state != RUNNING);
     }
 }
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/abort_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/abort_handler.c
index 8e13e7d86..693f6a987 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/abort_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/abort_handler.c
@@ -49,7 +49,7 @@ Modification:
 #include "task.h"
 
 extern void context_switch(struct context**, struct context*);
-void dabort_handler(struct trapframe* r)
+__attribute__((optimize("O0"))) void dabort_handler(struct trapframe* r)
 {
     if (r->pc >= DEV_VRTMEM_BASE && is_spinlock_hold_by_current_cpu(&whole_kernel_lock)) {
         assert(is_spinlock_hold_by_current_cpu(&whole_kernel_lock));
@@ -69,7 +69,7 @@ void dabort_handler(struct trapframe* r)
     panic("dabort end should never be reashed.\n");
 }
 
-void iabort_handler(struct trapframe* r)
+__attribute__((optimize("O0"))) void iabort_handler(struct trapframe* r)
 {
     if (r->pc >= DEV_VRTMEM_BASE && is_spinlock_hold_by_current_cpu(&whole_kernel_lock)) {
         assert(is_spinlock_hold_by_current_cpu(&whole_kernel_lock));
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
index 7c3dc2c81..2010d9c22 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
@@ -54,7 +54,7 @@ void default_interrupt_routine(void)
 }
 
 extern void context_switch(struct context**, struct context*);
-void intr_irq_dispatch(struct trapframe* tf)
+__attribute__((optimize("O0"))) void intr_irq_dispatch(struct trapframe* tf)
 {
     xizi_enter_kernel();
 
@@ -101,7 +101,7 @@ void xizi_enter_kernel()
     spinlock_lock(&whole_kernel_lock);
 }
 
-bool xizi_try_enter_kernel()
+inline bool xizi_try_enter_kernel()
 {
     /// @warning trampoline is responsible for closing interrupt
     if (spinlock_try_lock(&whole_kernel_lock)) {
@@ -111,7 +111,7 @@ bool xizi_try_enter_kernel()
     return false;
 }
 
-void xizi_leave_kernel()
+inline void xizi_leave_kernel()
 {
     /// @warning trampoline is responsible for eabling interrupt by using user's state register
     spinlock_unlock(&whole_kernel_lock);
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/software_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/software_irq_handler.c
index dce844139..500b7439c 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/software_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/software_irq_handler.c
@@ -46,7 +46,7 @@ bool swi_distributer_init(struct SwiDispatcherRightGroup* _right_group)
 }
 
 extern void context_switch(struct context**, struct context*);
-void software_irq_dispatch(struct trapframe* tf)
+__attribute__((optimize("O0"))) void software_irq_dispatch(struct trapframe* tf)
 {
     xizi_enter_kernel();
     assert(p_intr_driver != NULL);