Real-time intensive signal processing applications have been traditionally deployed on various custom platforms. Meanwhile, the enterprise computing market had spurred the advent of inexpensive and powerful systems based on widely available processors. Today, SMP systems associating a potentially large number of recent processors are deemed to cope with the needs of the most demanding real-time applications. On the operating system side, GNU/Linux is gaining wider acceptance and extending GNU/Linux to tackle real-time application scheduling is a common approach. We propose ARTiS, an asymmetric real-time scheduling for SMP systems. ARTiS ensures the possible preemption of a processor when the system has to schedule a real-time process. We have modified the GNU/Linux SMP scheduler to implement ARTiS. The evaluation of our approach shows significant improvements.