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Summary: Heterogeneous architectures offer the opportunity to achieve high performance and energy efficiency by selecting appropriate cores for the execution of ever‐changing software applications. Appropriate core selection depends on the interaction between the structural properties of the software and the hardware that influences the performance of the software. We propose a model for efficient core selection when executing software on ARM's big.LITTLE heterogeneous architecture. It features a metric based on the correlation between the performance and the number of last‐level data cache (LLC) misses on a big and a LITTLE core. Additionally, our model defines a soft threshold in terms of the number of LLC misses, which determines efficient core selection. We verify the model using stress and variable workload benchmarks as well as two popular high‐throughput applications for mutlicore targets, namely, HEVC and LDPC decoders, profiled with X‐Mem, Linux perf, and PMCTrack dynamic tools. Results show that our model can be used for efficient core selection with a relatively small error probability. [ABSTRACT FROM AUTHOR]

Spatial locality of task execution is becoming important in future hardware platforms since the number of cores is steadily increasing. The large amount of cores requires an intelligent power manager and the high chip and core density requires increased thermal awareness to avoid thermal hotspots on the chip. This paper presents a lightweight task migration mechanism explicitly for distributed operating systems running on many-core platforms. As the distributed OS runs one scheduler on each core, the tasks are migrated between OS kernels within the same shared memory platform. The benefits, such as performance and energy efficiency, of task migration are achieved by re-locating running tasks on the most appropriate cores and keeping the overhead of executing such a migration sufficiently low. We investigate the overhead of migrating tasks on a distributed OS running both on a bus-based platform and a many-core NoC-with these means of measures, we can predict the task migration overhead and pinpoint the emerging bottlenecks. With the presented task migration mechanism, we intend to improve the dynamism of power and performance characteristics in distributed many-core operating systems. [ABSTRACT FROM AUTHOR]

The main aim of this article is to discuss how the functional and the object-oriented views can be inter-played to represent the various modeling perspectives of embedded systems. We discuss whether the object-oriented modeling paradigm, the predominant one to develop software at the present time, is also adequate for modeling embedded software and how it can be used with the functional paradigm. More specifically, we present how the main modeling tool of the traditional structured methods, data flow diagrams, can be integrated in an object-oriented development strategy based on the unified modeling language. The rationale behind the approach is that both views are important for modeling purposes in embedded systems environments, and thus a combined and integrated model is not only useful, but also fundamental for developing complex systems. The approach was integrated in a model-driven engineering process, where tool support for the models used was provided. In addition, model transformations have been specified and implemented to automate the process. We exemplify the approach with an IPv6 router case study. [ABSTRACT FROM AUTHOR]