Real Time

This page has information about Real-time usage of Linux. Also this page has information about timing systems for Linux. This is of interest to CE Linux Forum members, because many consumer electronics products have realtime requirements (e.g. in the areas of multi-media presentation, or communications)

Real Time Wiki

 * Please note that the primary source of information for Real Time Linux information is the new RTWiki.

Technology/Project pages

 * Realtime Preemption - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
 * Kernel Timer Systems - Various new proposals for changing the kernel timing system
 * Soft IRQ Threads - Technology to put SoftIRQs in threads so they can be preempted.
 *  NOTE: Soft IRQ threads are now (Oct 2007) incorporated into the Realtime Preemption patch 
 * High Resolution Timers - A system to support timers with sub-jiffy resolution
 * Variable Scheduling Timeouts - A system to support variable timeouts for periodic system activities (also known as Tickless)

Documents

 * (expected July 15, 2008) Building Embedded Linux Systems, 2nd edition discusses the realtime preemption patch.
 * CELF Realtime Specification (from 2004, so it's pretty old)
 * Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
 * Realtime Testing Best Practices - a document to show recent testing results, and give hints for how different tests are conducted and what pitfalls to avoid.

Further Open Source Projects

 * Xenomai - Real-time development framework, closely cooperating with the Linux kernel. Among other features, it provides a migration path from various RTOSes like VxWorks, PSOS+, etc. to Linux based on so-called skins.