A more systematic approach is the second one: utilizing
Symmetric Multi-Processor (SMP) kernel, which was
invented by Montavista[l4]. In the SMP kernel, critical
regions are already coded and the kernel parts except
the critical regions are fully preemptable for SMP.
Montavista modifies spinlocks in the SMP kernel into preemtable
locks, applying the SMP technology to preemption
improvement in real-time processing.