Memory management

Protected address spaces

Although RTLinux is designed to run in processors with MMU, all the application threads and the RTLinux kernel run in the same address space. There is no memory protection between threads and the kernel and also between threads themselves.

From the point of view of memory management, RTLinux is the guest operating system of the Linux Kernel. The Linux kernel has the whole control of the memory.

Dynamic memory allocation:

RTLinux do not provide dynamic memory allocation nor use it internally. The main argument is that dynamic memory allocation is not predictable if implemented efficiently. The Real-Time goal of predictability is usually achieved by preallocating most of the resources the threads will use at run time.

It is possible to allocate all the memory that each thread will require before the threads are created.