Symmetric multiprocessing (SMP)

Allocating resources in a multicore design can be difficult, especially when multiple software components are unaware of how other components are employing those resources.

Symmetric multiprocessing addresses the issue by running only one copy of the QNX Neutrino RTOS on all of the system's CPUs. Because the OS has insight into all system elements at all times, it can allocate resources on the multiple CPUs with little or no input from the application designer. Moreover, QNX Neutrino provides built-in standardized primitives, such as pthread_mutex_lock(), pthread_mutex_unlock(), pthread_spin_lock(), and pthread_spin_unlock(), that let multiple applications share these resources safely and easily.

By running only one copy of QNX Neutrino, SMP can dynamically allocate resources to specific applications rather than to CPUs, thereby enabling greater utilization of available processing power. It also lets system tracing tools gather operating statistics and application interactions for the multiprocessing system as a whole, giving you valuable insight into how to optimize and debug applications.

For instance, the System Profiler in the IDE can track thread migration from one CPU to another, as well as OS primitive usage, scheduling events, application-to-application messaging, and other events, all with high-resolution timestamping. Application synchronization also becomes much easier since you use standard OS primitives rather than complex IPC mechanisms.

QNX Neutrino lets the threads of execution within an application run concurrently on any CPU, making the entire computing power of the chip available to applications at all times. QNX Neutrino's preemption and thread prioritization capabilities help you ensure that CPU cycles go to the application that needs them the most.