2008 Euromicro Conference on Real-Time Systems最新文献

{"title":"Real-Time Analysis for Memory Access in Media Processing SoCs: A Practical Approach","authors":"Elisabeth F. M. Steffens, Manvi Agarwal, P. V. D. Wolf","doi":"10.1109/ECRTS.2008.36","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.36","url":null,"abstract":"In shared-memory multi-processor systems on chip for media processing, the access to off-chip memory is often a critical resource. The memory channel is shared by a mix of streams with timing requirements at different levels. The streams are arbitrated in the memory access network. Some streams have to meet a hard deadline for each transaction; other streams have to meet task-level execution-time constraints, where task execution times depend on the service received when performing memory accesses. Earlier work has resulted in arbitration algorithms that provide the necessary balance between the different stream types, allowing aggressive system design with a high utilization of the memory access path. The next challenge is to provide real-time analysis in an early stage of system design. To address this challenge, this paper proposes a practical approach that combines proven analytical methods with fast simulations. The approach provides a design space from which to choose arbiter settings and buffer sizes for memory-communication buffers.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128159720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Analysis for Adapting Concurrent Applications to Embedded Systems","authors":"Sibin Mohan, J. Helander","doi":"10.1109/ECRTS.2008.38","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.38","url":null,"abstract":"Embedded services and applications that interact with the real world often,over time, need to run on different kinds of hardware (low-costmicrocontrollers to powerful multicore processors). It is difficult to writeone program that would work reliably on such a wide range of devices. This isespecially true when the application must be temporally predictable and robust,which is usually be the case since the physical world works in real-time.Thus, any application interacting with such a system, must also work inreal-time.In this paper we introduce a representation of the temporal behavior ofdistributed real-time applications as colored graphs that capture the timingof temporally continuous sections of execution and dependencies between them,creating a partial order. We then introduce a method of extracting the graphfrom existing applications using a combination of analysis techniques. Once thegraph has been created, we introduce a number of graph transformations thatextract ``meaning'' from the graph. The knowledge thus gained, can be utilizedfor scheduling and for adjusting the level of parallelism suitable to the specifichardware, for identifying hot spots, false parallelism, or even candidates foradditional concurrency. The importance of these contributions is evident whenwe see that such graphs can be sequentialized to our partiture model andcan then be used as input for offline, online, or even distributed real-timescheduling. Finally we present results from analysis of a complete TCP/IP stackin addition to smaller test applications which show that our use of differentanalysis models result in a reduction of the complexities of graphs. Animportant outcome is that increasing the expression of concurrency can reducethe level of parallelism required, saving memory on deeply embedded platforms,while keeping the program parallelizable whenever complete serializability isnot required. We also show that applications which were previously consideredto be too complex for characterization of their worst-case behavior are nowanalyzable due to the combination of analysis techniques that we utilize.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124816285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction and Deconstruction of Hierarchical Event Streams with Multiple Hierarchical Layers","authors":"J. Rox, R. Ernst","doi":"10.1109/ECRTS.2008.13","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.13","url":null,"abstract":"Compositional scheduling analysis couples local scheduling analysis via event streams. While local analysis has successfully been extended to include hierarchical scheduling strategies, event streams are still flat. In this paper, we formally define hierarchical event streams, which cannot only be constructed from flat event streams, but also from hierarchical streams allowing event streams with multiple hierarchical layers. We define an hierarchical event model and the operations to construct and deconstruct hierarchical events streams. Finally, we demonstrate how the model can be integrated in an existing analysis approach for distributed systems, enabling superior analysis results.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133486119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting the Behavior of a Highly Configurable Component Based Real-Time System","authors":"S. Hissam, Gabriel A. Moreno, Daniel Plakosh, Isak Savo, Marcin Stelmarczyk","doi":"10.1109/ECRTS.2008.7","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.7","url":null,"abstract":"Software components and the technology supporting component based software engineering contribute greatly to the rapid development and configuration of systems for a variety of application domains. Such domains go beyond desktop office applications and information systems supporting e-commerce, but include systems having real-time performance requirements and critical functionality. Discussed in this paper are the results from an experiment that demonstrates the ability to predict deadline satisfaction of threads in a real-time system where the functionality performed is based on the configuration of the assembled software components. Presented is the method used to abstract the large, legacy code base of the system software and the application software components in the system; the model of those abstractions based on available architecture documentation and empirically-based, runtime observations; and the analysis of the predictions which yielded objective confidence in the observations and model created which formed the underlying basis for the predictions.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"633 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116082577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time Divisible Load Scheduling with Advance Reservation","authors":"A. Mamat, Ying Lu, J. Deogun, S. Goddard","doi":"10.1109/ECRTS.2008.23","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.23","url":null,"abstract":"Providing QoS and performance guarantees to arbitrarily divisible loads has become a significant problem for many cluster-based research computing facilities. While progress is being made in scheduling arbitrarily divisible loads, previous approaches have no support for advance reservations. However, with the emergence of grid applications that require simultaneous access to multi-site resources, supporting advance reservations in a cluster has become increasingly important. In this paper we propose a new divisible load real-time scheduling algorithm that supports advance reservations in a cluster. Our approach not only enforces the real-time agreement but also addresses the under-utilization concerns raised by advance reservations. The impact of advance reservations on system performance is systematically studied. Simulation results show that, with the proposed algorithm and appropriate advance reservations, the system performance could be maintained at the same level as the no reservation case.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128041515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bounding Shared-Stack Usage in Systems with Offsets and Precedences","authors":"M. Bohlin, Kaj Hänninen, Jukka Mäki-Turja, Jan Carlson, Mikael Nolin","doi":"10.1109/ECRTS.2008.29","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.29","url":null,"abstract":"The paper presents two novel methods to bound the stack memory used in preemptive, shared stack, real-time systems. The first method is based on branch-and-bound search for possible preemption patterns, and the second one approximates the first in polynomial time. The work extends previous methods by considering a more general task-model, in which all tasks can share the same stack. In addition, the new methods account for precedence and offset relations. Thus, the methods give tight bounds for a large set of realistic systems. The methods have been implemented and a comprehensive evaluation, comparing our new methods against each other and against existing methods, is presented. The evaluation shows that our exact method can significantly reduce the amount of stack memory needed.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131144609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Impact of Task Preemption on Dependability in Time-Triggered Embedded Systems: A Pilot Study","authors":"M. Short, M. Pont, Jianzhong Fang","doi":"10.1109/ECRTS.2008.14","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.14","url":null,"abstract":"In this paper, we explore the impact of task preemption on the dependability of a single-processor embedded control system. Our particular focus in this exploratory study is on static-priority, time-triggered scheduler architectures. The study is empirical in nature and we employ a hardware-in-the-loop (HIL) testbed, representing a cruise control system for a passenger vehicle, in conjunction with fault-injection to perform the dependability comparisons. The results we have obtained suggest that the presence of preemption may have a negative influence on dependability; however further work is needed in this area before more general conclusions may be drawn.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122469619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WCET-driven Cache-based Procedure Positioning Optimizations","authors":"Paul Lokuciejewski, H. Falk, P. Marwedel","doi":"10.1109/ECRTS.2008.20","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.20","url":null,"abstract":"Procedure Positioning is a well known compiler optimization aiming at the improvement of the instruction cache behavior. A contiguous mapping of procedures calling each other frequently in the memory avoids overlapping of cache lines and thus decreases the number of cache conflict misses. In standard literature, these positioning techniques are guided by execution profile data and focus on an improved average-case performance. We present two novel positioning optimizations driven by worst-case execution time (WCET) information to effectively minimize the program's worst-case behavior. WCET reductions by 10% on average are achieved. Moreover, a combination of positioning and the WCET-driven Procedure Cloning optimization proposed in [14] is presented improving the WCET analysis by 36% on average.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121935805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fitting Schedulability Analysis Theory into Model-Driven Engineering","authors":"Matteo Bordin, Marco Panunzio, T. Vardanega","doi":"10.1109/ECRTS.2008.12","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.12","url":null,"abstract":"The theory behind state-of-the-art schedulability analysis has reached such a level of sophistication that its complete mastering by the average industrial practitioner is practically infeasible. The centrality of automation promoted by model-driven engineering may facilitate the uptake of the front-end of the analysis theory by the industrial world. In this paper we qualitatively evaluate how current approaches to model-based schedulability analysis may employ and feed state-of-the-art analysis equations; we then illustrate a new strategy which, by way of model transformation, warrants a high degree of confidence in and permits an iterative refinement of the input to sophisticated analysis equations. We contend that model-driven engineering is well suited for fitting the most advanced analysis theories and to chart the course for future improvements in the area of model-based schedulability analysis.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121994795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient Overclocking for Aperiodic Task Execution in Hard Real-Time Systems","authors":"Youngwoo Ahn, R. Bettati","doi":"10.1109/ECRTS.2008.32","DOIUrl":"https://doi.org/10.1109/ECRTS.2008.32","url":null,"abstract":"In this paper we study the design of aperiodic servers in thermally constrained real-time systems. We start by illustrating how naive slack stealing leads to missed deadlines in the presence of speed-control-based dynamic thermal management. We then proceed to describe a design time execution-budget allocation scheme that takes advantage of the predictable thermal behavior of the system to control the execution of aperiodic workload. We introduce the transient overclocking server, which safely reduces the response time for aperiodic jobs in the presence of hard real-time periodic tasks and thermal constraints. We show by simulation that the transient overclocking server works well under thermal constraints of the system, and that there is an optimal budget allocation that depends on the temporal characteristics of the aperiodic tasks.","PeriodicalId":176327,"journal":{"name":"2008 Euromicro Conference on Real-Time Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128941456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}