diff --git a/arch/x86/kernel/syscall.c b/arch/x86/kernel/syscall.c
index 99a5808f..b9b85d5e 100644
--- a/arch/x86/kernel/syscall.c
+++ b/arch/x86/kernel/syscall.c
@@ -274,30 +274,6 @@ do_signal(unsigned long rc, void *regs0, struct process *proc, struct sig_pendin
 		    case SIGCHLD:
 		    case SIGURG:
 			return;
-        case SIGSTOP: {
-            dkprintf("do_signal,SIGSTOP,changing state\n");
-            struct process *proc = cpu_local_var(current);
-            struct fork_tree_node *ftn = proc->ftn;
-            int exit_code = SIGSTOP;
-
-            /* Update process state in fork tree */
-            ihk_mc_spinlock_lock_noirq(&ftn->lock);	
-            ftn->exit_status = (exit_code << 8) | 0x7f;
-            ftn->status = PS_STOPPED;
-            ihk_mc_spinlock_unlock_noirq(&proc->ftn->lock);	
-
-            /* Wake up the parent who tried wait4 and sleeping */
-            waitq_wakeup(&proc->ftn->parent->waitpid_q);
-
-            dkprintf("do_signal,SIGSTOP,sleeping\n");
-            /* Sleep */
-            proc->status = PS_STOPPED;
-            schedule();
-            dkprintf("SIGSTOP(): woken up\n");
-            goto out; }
-        case SIGCONT:
-            dkprintf("do_signal,SIGCONT,do nothing\n");
-            goto out;
 		    case SIGQUIT:
 		    case SIGILL:
 		    case SIGTRAP:
@@ -312,7 +288,6 @@ do_signal(unsigned long rc, void *regs0, struct process *proc, struct sig_pendin
 		}
 		terminate(0, sig | coredumped, (ihk_mc_user_context_t *)regs->rsp);
 	}
- out:;
 }
 
 void
@@ -580,39 +555,21 @@ do_kill(int pid, int tid, int sig)
 	else{
 		ihk_mc_spinlock_unlock_noirq(&tproc->sigpendinglock);
 	}
-	dkprintf("do_kill,pid=%d,sig=%d\n", pid, sig);
+
 	if(doint && !(mask & tproc->sigmask.__val[0])){
 		int cpuid = tproc->cpu_id;
-		dkprintf("do_kill,proc=%p,tproc=%p\n", proc, tproc);
 		if(proc != tproc){
 			ihk_mc_interrupt_cpu(get_x86_cpu_local_variable(cpuid)->apic_id, 0xd0);
 		}
 		pid = tproc->pid;
 		ihk_mc_spinlock_unlock_noirq(savelock);
 		cpu_restore_interrupt(irqstate);
-		dkprintf("do_kill,sending kill to mcexec,pid=%d,cpuid=%d\n", pid, cpuid);
 		interrupt_syscall(pid, cpuid);
 	}
 	else{
 		ihk_mc_spinlock_unlock_noirq(savelock);
 		cpu_restore_interrupt(irqstate);
 	}
-    if(!(mask & tproc->sigmask.__val[0])) {
-        switch(sig) {
-        case SIGCONT:
-            dkprintf("do_kill,SIGCONT\n");
-            /* Wake up the target only when stopped by SIGSTOP */
-            sched_wakeup_process(tproc, PS_STOPPED);
-            if (tproc->ftn->status & PS_STOPPED) {
-                ihk_mc_spinlock_lock_noirq(&tproc->ftn->lock);	
-                xchg4((int *)(&tproc->ftn->status), PS_RUNNING);
-                ihk_mc_spinlock_unlock_noirq(&tproc->ftn->lock);	
-            } 
-            break;
-        default:
-            break;
-        }
-    }
 	return rc;
 }
 
diff --git a/kernel/include/process.h b/kernel/include/process.h
index 041f8963..04fbf8c8 100644
--- a/kernel/include/process.h
+++ b/kernel/include/process.h
@@ -51,7 +51,6 @@
 #define PS_UNINTERRUPTIBLE   0x4
 #define PS_ZOMBIE            0x8
 #define PS_EXITED            0x10
-#define PS_STOPPED           0x20
 
 #define PS_NORMAL	(PS_INTERRUPTIBLE | PS_UNINTERRUPTIBLE)
 
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 92b359cc..fd5f66f1 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -367,18 +367,6 @@ rescan:
 			if (ret != pid)
 				kprintf("WARNING: host waitpid failed?\n");
 
-			goto exit;
-		} else if(child->status == PS_STOPPED) {
-			ihk_mc_spinlock_unlock_noirq(&child->lock);
-			ihk_mc_spinlock_unlock_noirq(&proc->ftn->lock);
-
-			/* exit_status is created in do_signal */
-			if (status) {
-				*status = child->exit_status;
-			}
-			pid = child->pid;
-			dkprintf("wait4,PS_STOPPED,pid=%d,status=%08x\n", pid, *status);
-
 			goto exit;
 		}