Altreonic is pleased to release a new publication in its Gödel Series, entitled: "QoS and Real Time Requirements for Embedded Many- and Multicore Systems". While the first part is mainly a short summary on real-time scheduling, mostly Rate Monotonic Scheduling and Priority Inheritance support, it already establishes the jump to distributed real-time scheduling as supported in OpenComRTOS.
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The second part takes a closer look at modern advanced many/multi-core architectures, interrupt latency and inter-core communication measurements and makes the argument that the sharing of the on-chip resources, including the caches, makes it very hard to predict the temporal properties of an application. Rather than rejecting such advanced architectures, the argument is made to adapt the programming model to be able to handle the stochastic spread rather than trying to control it, even if a good design will try to minimise the spread.
Lastly, the bridge is made from Real-Time scheduling towards Quality of Service scheduling of on-chip resources. The connection is made with the specific case of Safety Integrity Levels. Finally, a proposal is made for a new concept that allows to classify components in terms of the assurance they provide for their functional requirements when resources are failing. Under the name ARRL (Assured Reliability and Resilience Level) it provides guidelines for selecting adequate architectures that allow to provide the required services in the presence of several classes of faults. This topic is the subject of on-going and future publications and provides the basis for extensions to the runtime support in OpenComRTOS.
The booklet if freely downloaded from Altreonic's website.
| Attachment | Size |
|---|---|
| RealTime and QoS scheduling.pdf [2] | 2.56 MB |