Kernel Locking Functions

The following functions are available to access RTX kernel memory locking services:

RtLockKernel locks pageable sections of the Windows kernel into physical memory.
RtUnlockKernel unlocks sections of the Windows kernel previously locked into physical memory.

RTSS Environment Programming Considerations

By default, all processes and memory objects in the RTSS environment are locked into physical memory.

Win32 Environment Programming Considerations

Certain Windows operating system components are paged, including most of the kernel and the Win32 subsystem. In order to prevent delays of your real-time processes due to kernel page faults, use the RtLockKernel function.

Windows device drivers generally do not page; device drivers loaded at boot time never page. In order to make drivers pageable by the system, the developer of that driver must carefully structure the driver and manually mark the code sections that are to be paged. Given the complexity, few drivers are structured in this way.

Locking the Windows kernel and processes reduces the pool of available physical memory. This can have a detrimental effect on the performance of non-real-time system operations. Adequate memory should be included in any system to accommodate the desired performance of any non-real-time operations. For information on non-paged pool size, go the Microsoft Knowledge Base or MSDN Web site.

Programming Example (RTX Kernel Memory Locking Calls)

See the RTX Kernel Memory Locking Calls Programming Example in the RTX Example Reference. It demonstrates the use of RTX kernel memory locking calls.