diff --git a/executer/kernel/mcctrl/procfs.c b/executer/kernel/mcctrl/procfs.c
index 36278bd8..96243fc4 100644
--- a/executer/kernel/mcctrl/procfs.c
+++ b/executer/kernel/mcctrl/procfs.c
@@ -749,7 +749,7 @@ int procfsm_packet_handler(void *os, int msg, int pid, unsigned long arg)
 {
 	struct procfs_work *work = NULL;
 
-	work = kzalloc(sizeof(*work), GFP_KERNEL);
+	work = kzalloc(sizeof(*work), GFP_ATOMIC);
 	if (!work) {
 		printk("%s: kzalloc failed\n", __FUNCTION__);
 		return -1;
diff --git a/executer/kernel/mcctrl/syscall.c b/executer/kernel/mcctrl/syscall.c
index 75124715..0042d323 100644
--- a/executer/kernel/mcctrl/syscall.c
+++ b/executer/kernel/mcctrl/syscall.c
@@ -281,7 +281,7 @@ static int remote_page_fault(struct mcctrl_usrdata *usrdata, void *fault_addr, u
 			phys, sizeof(*resp), NULL, 0);
 
 retry_alloc:
-	wqhln = kmalloc(sizeof(*wqhln), GFP_KERNEL);
+	wqhln = kmalloc(sizeof(*wqhln), GFP_ATOMIC);
 	if (!wqhln) {
 		printk("WARNING: coudln't alloc wait queue head, retrying..\n");
 		goto retry_alloc;
@@ -779,7 +779,7 @@ static int pager_req_create(ihk_os_t os, int fd, uintptr_t result_pa)
 
 		up(&pager_sem);
 
-		newpager = kzalloc(sizeof(*newpager), GFP_KERNEL);
+		newpager = kzalloc(sizeof(*newpager), GFP_ATOMIC);
 		if (!newpager) {
 			error = -ENOMEM;
 			printk("pager_req_create(%d,%lx):kzalloc failed. %d\n", fd, (long)result_pa, error);
@@ -1035,7 +1035,7 @@ static int pager_req_map(ihk_os_t os, int fd, size_t len, off_t off,
 	uintptr_t phys;
 
 	dprintk("pager_req_map(%p,%d,%lx,%lx,%lx)\n", os, fd, len, off, result_rpa);
-	pager = kzalloc(sizeof(*pager), GFP_KERNEL);
+	pager = kzalloc(sizeof(*pager), GFP_ATOMIC);
 	if (!pager) {
 		error = -ENOMEM;
 		printk("pager_req_map(%p,%d,%lx,%lx,%lx):kzalloc failed. %d\n", os, fd, len, off, result_rpa, error);
@@ -1514,7 +1514,7 @@ int __do_in_kernel_syscall(ihk_os_t os, struct ikc_scd_packet *packet)
 			struct mcctrl_per_proc_data *ppd = NULL;
 			int i;
 
-			ppd = kmalloc(sizeof(*ppd), GFP_KERNEL);
+			ppd = kmalloc(sizeof(*ppd), GFP_ATOMIC);
 			if (!ppd) {
 				printk("ERROR: allocating per process data\n");
 				error = -ENOMEM;
diff --git a/executer/kernel/mcctrl/sysfs.c b/executer/kernel/mcctrl/sysfs.c
index 0610862c..230a4996 100644
--- a/executer/kernel/mcctrl/sysfs.c
+++ b/executer/kernel/mcctrl/sysfs.c
@@ -1888,7 +1888,7 @@ sysfsm_packet_handler(void *os, int msg, int err, long arg1, long arg2)
 {
 	struct sysfs_work *work = NULL;
 
-	work = kzalloc(sizeof(*work), GFP_KERNEL);
+	work = kzalloc(sizeof(*work), GFP_ATOMIC);
 	if (!work) {
 		eprintk("mcctrl:sysfsm_packet_handler:kzalloc failed\n");
 		return;
diff --git a/kernel/syscall.c b/kernel/syscall.c
index dae81b9c..8d4b22ca 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -190,6 +190,9 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
 	dkprintf("SC(%d)[%3d] sending syscall\n",
 		ihk_mc_get_processor_id(),
 		req->number);
+	
+	irqstate = 0;	/* for avoidance of warning */
+	barrier();
 
 	if(req->number != __NR_exit_group){
 		if(proc->nohost && // host is down
@@ -199,7 +202,6 @@ long do_syscall(struct syscall_request *req, int cpu, int pid)
 		++thread->in_syscall_offload;
 	}
 
-	irqstate = 0;	/* for avoidance of warning */
 	if(req->number == __NR_exit_group ||
 	   req->number == __NR_gettid ||
 	   req->number == __NR_kill){ // interrupt syscall