diff --git a/kernel/arch/i386/klib386.S b/kernel/arch/i386/klib386.S
index 6e136cc11..852fa6c8b 100644
--- a/kernel/arch/i386/klib386.S
+++ b/kernel/arch/i386/klib386.S
@@ -692,3 +692,39 @@ idt_reload:
 reload_ds:
 	RELOAD_SEG_REG(%ds)
 	ret
+
+/*===========================================================================*/
+/*			      switch_address_space			     */
+/*===========================================================================*/
+/* PUBLIC void switch_address_space(struct proc *p)
+ *
+ * sets the %cr3 register to the supplied value if it is not already set to the
+ * same value in which case it would only result in an extra TLB flush which is
+ * not desirable
+ */
+ .balign 16
+.globl switch_address_space
+switch_address_space:
+
+	/* read the process pointer */
+	mov	4(%esp), %edx
+	/* enable process' segment descriptors  */
+	lldt	P_LDT_SEL(%edx)
+	/* get the new cr3 value */
+	movl	P_CR3(%edx), %eax
+	/* test if the new cr3 != NULL */
+	cmpl	$0, %eax
+	je	0f
+
+	/*
+	 * test if the cr3 is loaded with the current value to avoid unnecessary
+	 * TLB flushes
+	 */
+	mov	%cr3, %ecx
+	cmp	%ecx, %eax
+	je	0f
+	mov	%eax, %cr3
+	mov	%edx, ptproc
+	movl	$0, dirtypde
+0:
+	ret
diff --git a/kernel/arch/i386/mpx386.S b/kernel/arch/i386/mpx386.S
index d67ba0acc..321bc59a5 100644
--- a/kernel/arch/i386/mpx386.S
+++ b/kernel/arch/i386/mpx386.S
@@ -470,22 +470,6 @@ restart:
 	/* %eax is set by schedcheck() to the process to run */
 	mov	%eax, %ebp	/* will assume P_STACKBASE == 0 */
 
-	cmpl	$0, P_CR3(%ebp)
-	jz	0f
-
-	/*
-	 * test if the cr3 is loaded with the current value to avoid unnecessary
-	 * TLB flushes
-	 */
-	mov	P_CR3(%ebp), %eax
-	mov	%cr3, %ecx
-	cmp	%ecx, %eax
-	jz	0f
-	mov	%eax, %cr3
-	mov	%ebp, ptproc
-	movl	$0, dirtypde
-0:
-
 	/* reconstruct the stack for iret */
 	movl	SSREG(%ebp), %eax
 	push	%eax
@@ -500,7 +484,6 @@ restart:
 
 	RESTORE_GP_REGS(%ebp)
 
-	lldt	P_LDT_SEL(%ebp)	/* enable process' segment descriptors  */
 	RESTORE_SEGS(%ebp)
 
 	movl	%ss:BPREG(%ebp), %ebp
diff --git a/kernel/arch/i386/system.c b/kernel/arch/i386/system.c
index 703056cc3..d857eeece 100644
--- a/kernel/arch/i386/system.c
+++ b/kernel/arch/i386/system.c
@@ -477,9 +477,6 @@ PUBLIC void arch_do_syscall(struct proc *proc)
   m_ptr = (message *) proc->p_reg.bx;
   bit_map = proc->p_reg.dx;
 
-  /* do_ipc() expects the given process's memory to be accessible. */
-  vm_set_cr3(proc);
-
   /* Make the system call, for real this time. */
   proc->p_reg.retreg = do_ipc(call_nr, src_dst_e, m_ptr, bit_map);
 }
diff --git a/kernel/proc.c b/kernel/proc.c
index 99a2b202d..04062a105 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -198,6 +198,8 @@ not_runnable_pick_new:
 		idle();
 	}
 
+	switch_address_space(proc_ptr);
+
 check_misc_flags:
 
 	vmassert(proc_ptr);
diff --git a/kernel/proto.h b/kernel/proto.h
index 69c4d9f07..5226727a4 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -171,4 +171,5 @@ _PROTOTYPE( int arch_phys_map, (int index, phys_bytes *addr,
 _PROTOTYPE( int arch_phys_map_reply, (int index, vir_bytes addr));
 _PROTOTYPE( int arch_enable_paging, (void));
 
+_PROTOTYPE(void switch_address_space, (struct proc * p));
 #endif /* PROTO_H */