Difference between revisions of "Real Time"

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* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].
 
* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].
  
== Technology/Project pages ==
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== Software Projects ==
*[Realtime Preemption ''put link to patchset here'' - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
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* [[Realtime Preemption]] - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
*SoftIRQThreads ''put link here'' - Technology to put SoftIRQs in threads so they can be preempted. '''NOTE:''' This is now incorporated into the Realtime Preemption ''put link here'' patch
 
*High Resolution Timers ''put link here'' - A system to support timers with sub-jiffy resolution
 
*Variable Scheduling Timeouts ''put link here'' - A system to support variable timeouts for periodic system activities (also known as Tickless)
 
 
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
 
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
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* [[Soft IRQ Threads]] - Technology to put SoftIRQs in threads so they can be preempted.
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** '' '''NOTE:''' Soft IRQ threads are now (Oct 2007) incorporated into the [[Realtime Preemption]] patch ''
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* [[High Resolution Timers]] - A system to support timers with sub-jiffy resolution
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* [[Variable Scheduling Timeouts]] - A system to support variable timeouts for periodic system activities (also known as Tickless)
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== Hardware Implementations ==
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Ti AM18XX PRUSSv1
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[[Ti AM33XX PRUSSv2 | Ti_AM33XX_PRUSSv2]]
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Tools for PRUSS
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== Documents ==
 
== Documents ==
* CELF Specification - ''put link to PDF here''
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* [http://www.amazon.com/Building-Embedded-Linux-Systems-Yaghmour/dp/0596529686 Building Embedded Linux Systems, 2nd edition] discusses the realtime preemption patch.
*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - ''put link to PDF here'' Real-Time-Preemption-Patchset.pdf
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* [http://tree.celinuxforum.org/CelfPubWiki/RTSpecDraft_5fR2 CELF Realtime Specification] (from 2004, so it's pretty old)
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*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
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* [[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.
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* [http://free-electrons.com/articles/realtime/ Real time in embedded Linux systems]
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* [http://www.celinux.org/elc08_presentations/Using_Real-Time_Linux.KlaasVanGend.ELC2008.pdf Using Real-Time Linux] - Presentation by Klaas van Gends at the ELC 2008. The [http://free-electrons.com/pub/video/2008/elc/elc2008-klaas-van-gend-using-real-time-linux.ogg video] is available
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* Frank Rowand's series of talks
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** ''Adventures in real-time performance tuning''
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*** Part 1, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_1-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part1.ogv video] ELCE 2008 version
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*** Part 2, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_2-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part2.ogv video] ELCE 2008 version
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** Musings On Analysis of Measurements of a Real-Time Workload [http://tree.celinuxforum.org/CelfPubWiki/ELC2009Presentations?action=AttachFile&do=get&target=musings_on_analysis_of_measurements_of_a_real-time_workload.pdf slides] ELC 2009 version and [http://free-electrons.com/pub/video/2009/elce/elce2009-rowand-measurement-diagnostic-tools.ogv video]
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** Real-Time Linux Failure [[Media:Real_time_linux_failure.pdf|slides]] ELC 2010 version and [http://free-electrons.com/pub/video/2011/elc/elc-2011-rowand-real-time-issues-i-cache-locks.webm full HD video] and [http://free-electrons.com/pub/video/2011/elc/elc-2011-rowand-real-time-issues-i-cache-locks-x450p.webm 450x800 video]
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** How Linux PREEMPT_RT Works [[Media:elce11_rowand.pdf|slides]] ELCE 2011 version
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* ''Real-time vs real-fast, how to choose'', conference given by Paul E. McKenney at the Ottawa Linux Symposium 2008. [http://ols.fedoraproject.org/OLS/Reprints-2008/mckenney-reprint.pdf Paper] and [http://free-electrons.com/pub/video/2008/ols/ols2008-paul-mckenney-real-time-vs-real-fast.ogg video]
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* Paper: "[http://www.reliableembeddedsystems.com/pdfs/2010_03_04_rt_linux.pdf Embedded GNU/Linux and Real-Time an executive summary]", 2010 by Robert Berger
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** This papers, prepared for the Embedded World Conference 2010, compares different real-time approaches (including PREEMPT_RT and dual-kernel approaches).
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** The paper has an extensive list of references.
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* Tutorial [[RT-Preempt Tutorial]]
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* [https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html OSADL Realtime Page] with realtime latency [https://www.osadl.org/Continuous-latency-monitoring.qa-farm-monitoring.0.html testing] farm.
  
== Open Source Projects/Mailing Lists ==
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== Further Open Source Projects ==
*RTAIFusion ''put link here'' - Dual-kernel project. Fusion adds emphasis for support for realtime in user-space.
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* [http://www.xenomai.org 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.
  
 
[[Category:Real Time]]
 
[[Category:Real Time]]

Revision as of 14:52, 30 November 2011

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.

Software Projects

Hardware Implementations

Ti AM18XX PRUSSv1

Ti_AM33XX_PRUSSv2

Tools for PRUSS


Documents

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.