"Linux was originally written as a general-purpose operating system without any consideration for real-time applications. Recently Linux has become attractive to the real-time community due to its low cost and open standards. In order to make it more practical for the real-time community, patches have been written to affect such things as interrupt latency and context switch. These patches are public domain and are becoming part of the main Linux tree.
This article talks about one of these patches, the preemptible kernel patch, and its effect on the interrupt latency of a Linux system. The patch reduces the measured interrupt latency of the system, making it more appropriate for real-time applications."