User Tools

Site Tools


realtime:documentation:howto:debugging:cyclictest: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
Next revision Both sides next revision
realtime:documentation:howto:debugging:cyclictest:start [2018/08/06 10:28]
ebugden Change latency link title
realtime:documentation:howto:debugging:cyclictest:start [2018/08/06 13:00]
ebugden [Expected Results] Change link
Line 72: Line 72:
  
 It is not possible to specify a universally applicable recommended limit for latency length. The Cyclictest results should be analyzed based on the system'​s timing requirements for the latency of what was being measured. For example, if the latency of a specific real-time task was measured, then the results should be compared with the timing requirements for that specific task. The requirements will determine whether the latencies observed in a system are acceptable or too long. It is not possible to specify a universally applicable recommended limit for latency length. The Cyclictest results should be analyzed based on the system'​s timing requirements for the latency of what was being measured. For example, if the latency of a specific real-time task was measured, then the results should be compared with the timing requirements for that specific task. The requirements will determine whether the latencies observed in a system are acceptable or too long.
 +
 +==== Expected Results ====
  
 An interesting way of seeing how the tested system compares to other real-time platforms is to run Cyclictest with the same options that are used by OSADL to benchmark systems in their [[https://​www.osadl.org/​Latency-plots.latency-plots.0.html|Real-time QA Farm]] and to then compare the results with the results produced by their tested systems. The exact Cyclictest command used for a system is specified next to that system'​s latency plot. It is also possible to see a latency plot with the combined results of all the real-time devices that are currently being tested. An interesting way of seeing how the tested system compares to other real-time platforms is to run Cyclictest with the same options that are used by OSADL to benchmark systems in their [[https://​www.osadl.org/​Latency-plots.latency-plots.0.html|Real-time QA Farm]] and to then compare the results with the results produced by their tested systems. The exact Cyclictest command used for a system is specified next to that system'​s latency plot. It is also possible to see a latency plot with the combined results of all the real-time devices that are currently being tested.
 +
 +It can also be interesting to compare with results from other systems that were running loads, using various Cyclictest parameters, and running different real-time and non real-time kernels. These results give a general idea of the order of magnitude that the latencies should be. They also show the effect that different test conditions and parameters can have on the Cyclictest results.
 +
 +<WRAP rightalign>​[[realtime:​documentation:​howto:​debugging:​cyclictest:​result-examples|Read detailed examples of results]]</​WRAP>​
  
 ===== Test Design ===== ===== Test Design =====
Line 90: Line 96:
 ===== More Information ===== ===== More Information =====
  
-  * [[realtime:​documentation:​howto:​debugging:​cyclictest:​results-example|Detailed examples of results]] 
   * [[realtime:​documentation:​howto:​debugging:​cyclictest:​faq|Cyclictest FAQ]]   * [[realtime:​documentation:​howto:​debugging:​cyclictest:​faq|Cyclictest FAQ]]