August 24th, 2018 by
Real-time applications are applications that offer the right results on time. They focus on meeting the requirements of a time-related application aspect that could be stringent or soft. In today’s applications like those on smart phones, people run what they need on hardware and achieve their requirements immediately. The hardware may havededicated software or software that operates within the application area and the main processor to achieve effective command processing within the shortest time possible.
How Linux Kernel was Made Real-Time
Originally, Linux featured something known as a Big Kernel Lock (BKL). Large parts of the kernel were made pre-emptive to simplify operations and all tasks had to be executed to completion. As such, Linux required real-time capabilities to reduce the size of BKL. This in turn boosted responsiveness so Linux would perform other tasks.
This is how the RT-Preempt patch came into place. It was designed to replace kernel and offer the same instructions for handling interrupts and hardware latencies. It eliminated the need for artificial restrictions and protected the kernel in a refined manner. However, the RT-Preemptpatch is a work in progress to ensure that the Linux capabilities are improved and utilized to the fullest.
How Real-Time Linux Compares to a Windows Real-Time Operating System (RTOS)
The processor remains the same when running an RTOS or a Linux system. It does not perform faster in either of the two applications. This is because developers who write RTOS effectively follow similar instructions as developers who write Linux. Therefore, it is all about how the codeis organized for different intents and purposes. The latencies that can be achieved on Linux are similar to what you could achieve on a similar RTOS processor. All that is required is careful design to ensure that underlying hardware is maximally utilized to bring out the expected results.
Therefore, if you use the capabilities and functions of Linux in a particular way or configure them in a particular way, you can achieve low latency yet high performing environments that operate as if there is no OS running on a chip. It is all about using available features and adding others in an open source manner but in the Linux mainstream.
The RT-Preempt patch was designed to make Linux capable enough to work effectively when needed and when it makes sense to use it. For instance, if you put together a full RTOS, you would require 1 MB or 2 MB and it would be easy to get Linux to operate within this range. However, it would not make sense to use Linux when you require a tiny kernel or just a five line execution.