SMP - reduced TLB flushing

- flush TLB of processes only if the page tables has been changed and
  the page tables of this process are already loaded on this cpu which
  means that there might be stale entries in TLB. Until now SMP was
  always flushing TLB to make sure everything is consistent.

kernel/system/do_vmctl.c

@@ -148,6 +148,9 @@ PUBLIC int do_vmctl(struct proc * caller, message * m_ptr)
 		} else
 #endif
 			RTS_SET(p, RTS_VMINHIBIT);
+#if CONFIG_SMP
+		p->p_misc_flags |= MF_FLUSH_TLB;
+#endif
 		return OK;
 	case VMCTL_VMINHIBIT_CLEAR:
 		assert(RTS_ISSET(p, RTS_VMINHIBIT));