
Mastering Embedded Linux Programming
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There is a long-standing effort to reduce latencies still further which goes by the name of the kernel configuration option for these features, PREEMPT_RT
. The project was started by Ingo Molnar, Thomas Gleixner, and Steven Rostedt and has had contributions from many more developers over the years. The kernel patches are at https://www.kernel.org/pub/linux/kernel/projects/rt and there is a wiki, including an FAQ (slightly out of date), at https://rt.wiki.kernel.org.
Many parts of the project have been incorporated into mainline Linux over the years, including high resolution timers, kernel mutexes, and threaded interrupt handlers. However, the core patches remain outside of the mainline because they are rather intrusive and (some claim) only benefit a small percentage of the total Linux user base. Maybe, one day, the whole patch set will be merged upstream.
The central plan is to reduce the amount of time the kernel spends running in an atomic context...