runaway latency detection

From: T. Smith
Date: Sat Aug 20 2016 - 13:04:00 EST

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Trying to isolate PREEMPT_RT (full preemption) runaway latency conditions seen when using the cyclictest on the 4.1.8 SMP PREEMPT_RT kernel. Seen average latency of 3uS, but runaway or outlier max latency seems indeterminate. Noted 72uS with one run of the cyclictest for example. Is this a known issue, the cause understood, and is there a patch for this?

The goal is to isolate causes of indeterminism when using the PREEMPT_RT kernel configuration with full preemption and to characterize latency and jitter using ftrace, any recommendations?

Next message: T. Smith: "Moving GPIO interrupts and IPIs to a core other than 0"
Previous message: SF Markus Elfring: "[PATCH 3/3] hostap: Delete unnecessary initialisations for the variable "ret""
Next in thread: Nikolay Borisov: "Re: runaway latency detection"
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