User Tools

Site Tools


realtime:documentation:start

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
realtime:documentation:start [2017/02/08 14:12]
anna-maria all howtos are now in own subnamespaces
realtime:documentation:start [2023/10/02 08:43] (current)
costa.shul fix layout
Line 9: Line 9:
  
 <WRAP half column> <WRAP half column>
 +===== HOWTOs =====
 +
 +There are three categories of HOWTOs:
 +
 +  * [[realtime:​documentation:​howto:​applications:​start|RTOS and RT application]]
 +  * [[realtime:​documentation:​howto:​debugging:​start|RT latency debugging]]
 +  * [[realtime:​documentation:​howto:​tools:​start|RT tools and utilities]]
 +
 ===== Technical Basics ===== ===== Technical Basics =====
  
Line 19: Line 27:
 <WRAP rightalign>​[[realtime:​documentation:​technical_basics:​start|Read more about technical basics]]</​WRAP>​ <WRAP rightalign>​[[realtime:​documentation:​technical_basics:​start|Read more about technical basics]]</​WRAP>​
  
-</​WRAP>​ 
- 
-<WRAP half column> 
 ===== Technical details of PREEMPT_RT patch ===== ===== Technical details of PREEMPT_RT patch =====
  
 The main aim of the PREEMPT_RT patch is to //minimize the amount of kernel code that is non-preemptible//​ ((Paul McKenney. A realtime preemption overview. [[https://​lwn.net/​Articles/​146861/​]])). Therefore several substitution mechanisms and new mechanisms are implemented. The main aim of the PREEMPT_RT patch is to //minimize the amount of kernel code that is non-preemptible//​ ((Paul McKenney. A realtime preemption overview. [[https://​lwn.net/​Articles/​146861/​]])). Therefore several substitution mechanisms and new mechanisms are implemented.
  
-<WRAP rightalign>​[[realtime:​documentation:​technical_preempt_rt|Read more about technical details]]</​WRAP>​+<WRAP rightalign>​[[realtime:​documentation:​technical_details:​start|Read more about technical details]]</​WRAP>​
  
-</​WRAP>​+===== Publications =====
  
-<WRAP half column>+Several real-time related publications can help broaden your knowledge 
 +about real-time systems. Regarding PREEMPT_RT, a recent survey of available scientific works 
 +[[https://​dl.acm.org/​citation.cfm?​id=3297714|have been published]] ([[https://​re.public.polimi.it/​handle/​11311/​1076057|open access link]]).
  
-===== HOWTOs =====+<WRAP rightalign>​[[realtime:​documentation:​publications|Read more about publications]]</​WRAP>​
  
-There are three categories of HOWTOs: 
  
-  * [[realtime:​documentation:​howto:​applications:​start|RTOS and RT application]]+===== Known Limitations =====
  
-  * [[realtime:​documentation:​howto:​debugging:​start|RT Debugging]]+Some functionality is not available on RT because its implementation 
 +is not compatible with RT. Those limitations may apply to the to the 
 +kernel as a whole or may apply to specific architecture or platforms. 
 + 
 +<WRAP rightalign>​[[realtime:​documentation:​known_limitations|Read more about known limitations]]</​WRAP>​
  
-  * [[realtime:​documentation:​howto:​tools:​start|RT tools and utilities]] 
  
 </​WRAP>​ </​WRAP>​
  
 <WRAP half column> <WRAP half column>
-===== Publications ​=====+===== Stable RT Releases ​=====
  
-Several real-time related publications ​can help broaden your knowledge +If the PREEMPT_RT patch was ported to a Linux kernel version that is flagged as a [[https://​kernel.org|stable release at kernel.org]],​ then that port will continue to be forward ported with each new stable release for that kernel version. The stable kernels ​can be cloned from the [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​rt/​linux-stable-rt.git/​|stable git repository]] as well as downloaded as [[https://​mirrors.edge.kernel.org/​pub/​linux/​kernel/​projects/​rt/​|single patches or a tarball of a quilt series of patches]].
-about real-time systems.+
  
-<WRAP rightalign>​[[realtime:​documentation:​publications|Read more about publications]]</​WRAP>​+The PREEMPT_RT stable releases are updated in two fashions.
  
 +  * Merged with the upstream Linux stable kernel.
  
-</WRAP>+  * Backports of commits from the [[https://​git.kernel.org/​pub/​scm/​linux/​kernel/​git/​rt/​linux-rt-devel.git/​|current PREEMPT_RT development repository]]
  
 +Tagging policy of the PREEMPT_RT stable releases. Each PREEMPT_RT stable release is tagged with the version number of the upstream Linux stable kernel as well as its own "​-rt"​ counter that is appended. The -rt counter will increment for the following:
  
-<WRAP half column>​ +  * When forward ported to the latest upstream Linux stable version.
-===== Known Limitations =====+
  
-Some functionality is not available on RT because its implementation +  * When any merge with a upstream Linux stable causes a conflict.
-is not compatible ​with RT. Those limitations may apply to the to the +
-kernel as whole or may apply to specific architecture or platforms.+
  
-<WRAP rightalign>​[[realtime:​documentation:​known_limitations|Read more about known limitations]]</​WRAP>​+  * When a backport of the PREEMPT_RT development branch is done. 
 + 
 +A backport will not be done with a forward port of a stable version. They will be done separately, and tagged separately.
  
 +The "​-rebase"​ branch is how the series of patches are created. The "​-rebase"​ is only done for forward ports to the latest upstream Linux stable versions, and for backports of the PREEMPT_RT development branch. It is not done for a conflict with a upstream Linux stable merge, unless that stable version is the latest one. As the name suggests, the "​-rebase"​ branch will rebase, to allow each commit added by the PREEMPT_RT code to be applied in the order to the upstream Linux stable version it is based on. This is not the case with the normal "​-rt"​ branch, which is never rebased.
  
 </​WRAP>​ </​WRAP>​
  
 +----
  
 +<WRAP rightalign>​Go back to [[realtime:​start|Real-Time Main Page]]</​WRAP>​
realtime/documentation/start.1486563140.txt.gz · Last modified: 2017/02/08 14:12 by anna-maria