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--- realtime:documentation:howto:debugging:cyclictest:details [2018/07/24 09:40]
ebugden [Execution] Correct typo
+++ realtime:documentation:howto:debugging:cyclictest:details [2018/08/06 09:00]
ebugden Move content to start page
@@ Line 14: / Line 14: @@
   * [[realtime:documentation:howto:debugging:cyclictest:debugging|Latency debugging]]
   * [[realtime:documentation:howto:debugging:cyclictest:app-performance|Approximating application performance]]
+OSADL (Open Source Automation Development Lab) uses Cyclictest to continuously monitor the latencies of several systems. More details about the project and about the specific Cyclictest options they use can be found on the [[https://www.osadl.org/Continuous-latency-monitoring.qa-farm-monitoring.0.html|OSADL website]].
+===== Technical Explanation =====
+To measure latencies, Cyclictest runs a non real-time master thread (scheduling class SCHED_OTHER) which starts a defined number of measuring threads with a defined real-time priority (scheduling class SCHED_FIFO). The measuring threads are woken up periodically with a defined interval by an expiring timer (cyclic alarm). Subsequently, the difference between the programmed and the effective wake-up time is calculated and handed over to the master thread via shared memory. The master thread tracks the latency values and prints the minimum, maximum, and average latencies.
 ===== Installation =====

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