Prestigious Test Of Time Award at ESWEEK 2023 for Memory Controller Research

I am happy to announce that we received the Test Of Time Award for CODES+ISSS at ACM/IEEE Embedded Systems Week (ESWEEK) 2023 in Hamburg, Germany. The Test of Time Award is the most prestigious award of ESWEEK and honors the authors of papers of previous editions of the co-located conferences (CASES 2008, CODES+ISSS 2007, and EMSOFT 2007) that had the highest impact. We received this award for my first paper as a PhD student “Predator: a predictable SDRAM memory controller“, which written with co-authors Kees Goossens and Markus Ringhofer and published in CODES+ISSS 2007.

The paper addressed the problem of providing guarantees on bandwidth and latency to ports on an SDRAM memory controller, a key component of a system-on-chip. Previously, this was only done for statically scheduled memory controllers that assumed the workload of memory requests was known a priori. While this limitation was acceptable for simple systems, increasing integration of functionality in consumer electronics products like set-top boxes challenged this assumption, requiring more dynamic solutions. To this end, the paper presented concepts, hardware architecture, and performance analysis for a more dynamic SDRAM memory controller for real-time systems.

This work formed the base for my memory research, which evolved into a research line that would continue for over a decade and in which six PhD students eventually graduated. In total, this research resulted in a body of work of 30+ papers and two books, which together have been cited more than 2000 times. It also resulted in the open-source tool DRAMPower, which is used to estimate energy consumption of memories. This tool has been integrated in the popular Gem5 simulator and is widely used by the computer architecture community.

The paper was impactful because it was one of the first papers about memory controllers for real-time systems. More papers would follow from Barcelona Supercomputing Center, UC Berkley, and University of Waterloo. Step by step, the proposed memory controllers would become more dynamic and the analysis more sophisticated. This continued until the middle of the previous decade, at which the field moved more from proposing and analyzing new memory controller architectures for systems-on-chips to configuring and analyzing commercial-of-the-shelf memory controllers. This is still an active field of research in the real-time systems community today.

“Receiving this award is an unexpected honor, and I extend my heartfelt thanks to my co-authors and everyone that contributed to subsequent advancements in this field, in particular my former PhD students Karthik Chandrasekar, Manil Dev Gomony, Sven Goossens, Yonghui Li, and Anna Minaeva. Together, we created, developed, and matured the research field of memory controllers for real-time systems.”

Call for Papers and Experts – 30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024) in Hong Kong

I have the honor of being the Program Chair of the 30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024), located in Hong Kong May 13-16 next year. Please see the Call for Papers below.

Soon, it will be time to put together the Technical Program Committee (TPC) that will review and select the papers that will appear in the conference program. If you are interested in joining the TPC of this conference, or any other conference (co-)sponsored by the Technical Community of Real-Time Systems (TCRTS), please fill out the TPC self-nomination form as soon as possible. We always welcome self-nominations from our own community, but this year we especially encourage self-nominations from the academic performance engineering community, as well as members of the industry that work with real-time requirements or performance engineering, defined in a broad sense.

If you have any questions, please feel to reach out to me. If want to self-nominate, click this link. A self-nomination is not a firm commitment, it is just a declaration of interest that may result in an invitation.

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30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024)

Hong Kong, May 13-16, 2024

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CALL FOR PAPERS

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RTAS is a top-tier conference with a focus on time-sensitive systems. RTAS’24 invites papers describing case studies, applications, methodologies, and algorithms that contribute to the state of practice in design, implementation, verification, validation, and evolution of time-sensitive systems. RTAS’24 consists of two tracks:

  • Track 1. Systems and Applications;
  • Track 2. Applied Methodologies and Foundations.

In both tracks, papers must consider some kind of timing requirements. The timing requirements of interest are broadly defined and include not only classical hard real-time constraints, but also soft real-time, probabilistic, quality-of-service (QoS), throughput or latency requirements. The application area can be any type of time-sensitive systems, ranging from resource-constrained embedded systems to cyber-physical systems (CPS), cloud/edge/fog computing systems, cloud data centers, Internet of Things (IoT), mobile computing, robotics,  smart grid, and smart cities, as well as middleware and frameworks, machine learning in or for time-sensitive systems and signal processing algorithms that execute in real time. RTAS welcomes both papers backed by formal proofs, as well as papers that focus exclusively on empirical validation of timing requirements, e.g., using traces or performance models inferred from operational data. Research results from fundamental research, (case-driven) applied research, and (pragmatic) industry practice are all in scope.

RTAS’24 follows a double-anonymous peer reviewing process: author identities and affiliations will not be revealed to reviewers. Authors will have the opportunity to provide a response to reviews before acceptance decisions are made, solely to provide clarifications and correct misconceptions. The response will not allow authors to introduce new material beyond the original submission, or promise such material for the camera-ready version. There will be an optional evaluation process for accepted papers that assesses the reproducibility of the work.

Track 1: Systems and Applications

This track focuses on research of an empirical nature pertaining to (system- or component-) level analysis, optimization, and verification, as well as applications, runtime software, and hardware architectures for time-sensitive systems.

Topics relevant to this track include, but are not limited to:

  • time-sensitive applications
  • real-time and embedded operating systems,
  • hypervisors and runtime frameworks,
  • hardware architectures, memory hierarchies, FPGAs, GPUs and accelerators,
  • time-sensitive networks, CPS/IoT infrastructure,
  • microservice technologies, cloud and edge computing, real-time artificial intelligence and machine learning,
  • application profiling, WCET analysis, compilers, tools, benchmarks and case studies.

Papers discussing design and implementation experiences on real industrial systems are especially encouraged. Papers submitted to this track should focus on specific systems and implementations. Authors must include a section with experimental results performed on a real implementation, or demonstrate applicability to an industrial case study or working system. The experiment or case study discussions must highlight the key lessons learned. Simulation-based results are acceptable for architectural simulation, or other cases where authors clearly motivate why it is not feasible to develop and evaluate a real system.

Empirical survey-based research focused on the real-time systems field is also welcome in this track. This type of research uses surveys, questionnaires, interviews, use cases or other empirical techniques to obtain information about the past / current / future state of play in the research, design, development, verification, validation, and deployment of time-sensitive systems.

Track 2: Applied Methodologies and Foundations

This track focuses on fundamental models, and analysis techniques/methods that are applicable to time-sensitive systems to solve specific problems. The track welcomes knowledge-based models, models built from operational data, as well as a combination, and different types of analysis methods, including analytical, statistical, or probabilistic methods. Topics relevant to this track include, but are not limited to:

  • modelling languages, modelling methods, model learning, model validation and calibration,
  • scheduling and resource allocation,
  • system-level optimization and co-design techniques,
  • design space exploration,
  • verification and validation methodologies.

Papers must describe the main context or use case for the proposed methods giving clear motivating examples based on real systems. The system models and any assumptions used in the derivation of the methods must be applicable to real systems, and reflect actual needs. Papers must include a section on experimental results, preferably including a case study based on information from a real system. The use of synthetic workloads and models is acceptable if appropriately motivated and used to provide a systematic evaluation.

Important Dates

Submission Deadline (firm): October 31, 2023
Author Response Period: January 8-12, 2024
Author Notification: January 19, 2024
Conference Date: May 13-16, 2024

 

Bridging the Gap: Rethinking Real-Time Systems for Industry Success and Model-Driven Performance Engineering

The real-time systems community is shrinking and needs to bridge the gap between academic research an industry practice. In my pitch at ECRTS, I shared our view on model-driven system performance engineering for cyber-physical systems and encouraged the community increase its scope and take a broader responsibility for timing-related issues in systems to achieve those goals. This means working in more of the focus areas that we have identified in our vision and validated with our industry partners, but also reconsidering some directions in areas where work is already taking place. This means less focus on hard real-time requirements and formal methods and more focus on:

• system-level KPIs instead of meeting deadlines in subsystems
• soft real-time requirements
• timing requirements beyond software
• system performance modelling, model calibration, and model learning
• data-driven performance analysis, optimization, verification, and diagnostics, e.g. using traces

I encouraged the community to have a look at our vision for model-based system performance engineering for industrial cyber-physical systems and asked to think about how they could contribute through their current and future work.

Please have a look at our vision here.

Thanks to Bram van der Sanden, Kuan-Hsun Chen, Mitra Nasri, Geoffrey Nelissen, and Twan Basten for their help preparing the pitch.

Optimizing Efficiency and Performance: PhD Thesis Defense on Energy- and Time-aware Scheduling for High-Performance Embedded Systems

Yesterday, I participated in the PhD defense committee of Julius Röder, a PhD student in the Parallel Computing Systems group at the University of Amsterdam. The thesis “Energy- and Time-aware Scheduling for Heterogeneous High-Performance Embedded Systems” addresses the relevant problem of optimizing non-functional behavior, such as timing and energy consumption, of heterogeneous high-performance embedded systems. The goal of this optimization Is to reduce energy consumption, thereby also reducing carbon footprint and extending battery-life, as well as ensuring that real-time requirements of applications are satisfied, even at high resource utilizations. To this end, the thesis contributes a discussion on setups used for energy measurements, as well as experiments and a statistical analysis that demonstrate the Importance of sampling frequency on the accuracy of such measurements. The bulk of the thesis proposes heuristic algorithms, both conventional and based on reinforcement learning, for mapping and scheduling applications modelled as directed acyclic graphs (DAG) on heterogeneous platforms. The applications are assumed to be available In different versions, with different non-functional behavior, for the different types of processing elements In the heterogeneous architecture, which enables trade-offs between timing and energy. A key strength of the thesis is that theory is combined with a practical component; the scheduling algorithms are implemented and evaluated on a heterogeneous multi-core systems, where timing and energy behavior are carefully measured and analyzed.

In presence of family, friends, and colleagues, Julius confidently defended his PhD thesis and earned the right to call himself a doctor. Congratulations Julius with this great achievement!

Driving Innovation and Collaboration: Dutch Real-time Days Event Sparks Ideas for Future Research and Industry Relevance

I recently co-organized a Dutch Real-time Days event together with real-time systems researchers from TU/e and UT. The event was funded through a 4TU.NIRICT Call Community Funding and its goals were to:

1) share and develop new ideas for real-time systems research,
2) stimulate new collaborations, and
3) networking.

In addition to the four organizers from the Netherlands, Mitra Nasri (TU/e), Geoffrey Nelissen (TU/e), Kuan-Hsun Chen (UT), and myself, four well-established European researchers in the area of real-time systems were invited to the event. Everybody was invited to pitch their current work, ideas for future directions, and appropriate mechanisms to support collaborations. This was followed by brainstorming sessions were these ideas were creatively improved, as well as a working session where some of the ideas were discussed in more detail and made actionable. At the end of the first day, there was a lovely dinner at Restaurant Giornale in Eindhoven, providing further room for discussions and networking.

The outcome of the two days was a mix of technical ideas that can be pursued in future research papers or project proposals, and actions to shape direction of the academic real-time systems community and further increase its industrial relevance. For example, we agreed to propose that the Technical Community on Real-time Systems (TCRTS) adds an award for industry impact/technology transfer and propose a special issue on industry challenges/visions in the Journal of Real-time Systems.

RTSS@Work 2022 Proceedings Online

I have had the honor to serve as the chair of RTSS@Work 2022, the open demo session organized as a part of the 43rd IEEE Real-Time Systems Symposium, held in Houston, Texas on December 6, 2022. The goal of RTSS@Work is to provide a platform for researchers to present prototypes, tools, simulators, and systems, which extend the state-of-the-art in Real-Time Technologies and Techniques. It augments the traditional forum by enabling presenters to demonstrate working systems, thereby allowing them to directly engage with the audience, generate interest in new research topics, and encourage wider adoption of common frameworks.

This year’s RTSS@Work was very special, as it was the first physical instance after years of virtual events due to the COVID pandemic. It was nice to meet each other again and to physically demonstrate and discuss the work we have done. While the COVID pandemic reduced the number of submissions in previous years, I am happy to announce that we had nine demo submissions this year, on par with the pre-pandemic era. The program committee, comprising seven researchers, selected eight demos to appear in the session. I would like to thank the program committee for accepting my invitation and for spending their time reviewing and selecting the demo abstracts. I would also like to thank the authors for submitting to RTSS@Work, for delivering the camera-ready abstracts on time, and for demonstrating their work at the conference.

The proceedings of RTSS@Work 2022 are now available online.

Proposal Building Dutch Real-time Systems Community Granted

Recently, I submitted a small proposal worth 5K euro to the 4TU.NIRICT Call Community Funding together with Mitra Nasri and Geoffrey Nelissen, both from Eindhoven University of Technology, and Kuan-Hsun Chen from University of Twente. The purpose of the proposal was for creating a Dutch Real-time Systems community and stimulate collaboration both nationally and at the European level. Earlier this week, we were notified that the proposal was granted!

We plan to use the funding for building a Dutch real-time systems community by organizing a workshop in the Netherlands with several invited speakers (around 6) from other European countries, followed by a consolidation event after 3 months. The duration of the workshop will two days, and the target audience is the domain researchers affiliated with the 4TU and UvA. On each workshop day, there will be keynotes, rapid pitch talks, interactive panels, reviews of funding opportunities, and social meetings. The one-day consolidation event, (e.g., three months later) will focus on strengthening the Dutch real-time system community vision and on consolidating the initiatives planned at the workshop.

I look forward to working with Mitra, Geoffrey, and Kuan to organize a strong real-time systems community in the Netherlands through this grant, and through other means.

 

Article about Survey-based Study into Industry Practice in Real-time Systems in Real-time Systems Journal

It has been almost a year since we published the first survey-based study in the area of real-time systems at the Real-time Systems Symposium (RTSS) back in December 2020. The paper was entitled “An Empirical Survey-based Study into Industry Practice in Real-time Systems” and had the ambitious goal of addressing the gap between academic research and industry practice through an empirical survey-based study into industry practice. The survey had five objectives: 1) Establish whether timing predictability is of concern to the real-time embedded systems industry, 2) Identify relevant industrial problem contexts, including hardware platforms, middleware, and software, 3) Determine which methods and tools are used to achieve timing predictability, 4) Establish which techniques and tools are used to satisfy real-time requirements, and 5) Determine trends for future real-time systems. The survey was completed by 120 industry practitioners in the field of real-time embedded systems, which allowed interesting observations and insights to be made about the characteristics of the systems being developed today and important trends for the future.

Now, almost one year later, I am happy to announce that an extended version of our RTSS paper has been accepted for publication in the Real-time Systems journal. The title of the article is “A Comprehensive Survey of Industry Practice in Real-Time Systems“. The main extensions in the article include: 1) a discussion of potential threats to validity of the survey and its results, as well as the steps taken to mitigate them, 2) a statistical analysis and discussion of the results of the survey, in the context of its five objectives, 3) a discussion of the results of a quiz aimed at determining if the aggregate findings of the survey are common knowledge in the real-time systems community. In addition, more aggregated data from the survey has been released, allowing interested readers to further delve into the similarities and differences between the avionics, automotive, and consumer electronic domains.

We hope that you enjoy the article!

An Empirical Survey-based Study into Industry Practice in Real-time Systems @ RTSS 2020

It is my great pleasure to announce that our paper “An Empirical Survey-based Study into Industry Practice in Real-time Systems” has appeared at the 41st IEEE Real-Time Systems Symposium (RTSS). The paper presents results and observations from a survey of 120 industry practitioners in the field of real-time embedded systems. The survey provides insights into the characteristics of the systems being developed today and identifies important trends for the future. The survey aims to inform both academics and practitioners, helping to avoid divergence between industry practice and fundamental academic research.

This work is a dear pet project of mine that has been a long time in the making. Once I joined ESI (TNO), I started reading papers and attending conferences in the modelling community. I came across empirical survey-based research that systematically investigated industry trends, needs and practices, and that studied adoption and perceived benefits and drawbacks of different technologies and methodologies. I immediately found this line of work incredibly useful as it elevated my understanding of what happened in industry from a collection of anecdotes based on conversations with a few people in a few companies to something that could capture the experience of hundreds of people across industrial domains. I also had the feeling that this line of work provided all the citations I needed for the introduction of my papers, as it helped me position my own work on modelling in a broader industrial reality.

Empirical research is an established research direction in social science, but also in technical fields, such as software engineering and to a lesser extent system engineering. However, there was no work like this in the area of real-time systems. I decided to change this and pitched the idea to Rob Davis, Mitra Nasri, and Geoffrey Nelissen and Sebastian Altmeyer during a meeting in Amsterdam in May 2019. They substantially improved on my ideas and did a lot of very good work and almost a year and a half later, the paper is available for you to read. We could not fit everything we had to say into the RTSS paper, so there is also a supporting technical note entitled “A Comprehensive Survey of Industry Practice in Real-time Systems“.

RTSS Session

A separate session was dedicated to this work on the last day of RTSS 2020. The session began with a 25 minute paper presentation, which is available here:

The paper presentation was followed by a panel discussion involving three industry practitioners from the three main industrial domains covered by the survey: Marcelo Lopez Ruiz (Microsoft), representing the consumer electronics industry, Simon Schliecker (Volkswagen), representing automotive, and Stephen Law (Rolls-Royce), providing an avionics perspective. The panel discussed four key questions relating to the survey results:

Q1. What important characteristics of real-time systems highlighted in the survey results are the most relevant with respect to your industry? And what other important characteristics are there that were not picked up by the survey?

Q2. What are the most relevant trends in real-time systems development in your industry now, and looking ahead over the next 10 years?

Q3.  Did anything surprise you in the survey and its results? And why?

Q4. Given the results of the survey, and your own experience, what recommendations would you to give to the academic community? Which areas should we work more or less on? What assumptions should we make or not make?

The opening statements from the panelists related to the four questions was pre-recorded and followed by a live discussion. The pre-recorded part of the panel is available here:

The session finished after one hour, before there was time to take questions from the audience. A separate Zoom room was created for this purpose and to allow the interaction to continue, which it did for another hour! We were very pleased with the interest in this paper and in the session.

Emerging Research Direction

I hope that this work is the first of many empirical research papers in real-time systems. There are many ways to continue with this line of work. First of all, others need to replicate our results to validate that they hold for different populations. For this purpose, we will be happy to transfer the survey we made on SurveyMonkey, such that it can be reused. Secondly, our survey was very broad and covers real-time systems across many application domains. More specific questions could be obtained if the focus was on a single domain, although the main challenge will be finding enough representative participants with a narrow focus. Thirdly, surveys are only one way of conducting empirical research. Another method sometimes used in software engineering is to use interviews, allowing more in-depth questions to be asked. However, the drawback of this method is that it is more time consuming to interview are large number of participants and to encode and analyze the results.

This direction in real-time system research is just emerging and we hope it will grow and become a well-established part of the research conducted in the community. This would help us better understand the industry we are trying to serve and help us close the gap between academic research and industry practice. A first important step is that this direction is recognized by all main conferences and journals in the area of real-time systems and explicitly included in the call for papers. You can play an important part here by helping us communicate the value of empirical research to others in our community and beyond.

Another Article in Real-time Systems Journal

An article entitled “Response Time Analysis of Multiframe Mixed-Criticality Systems with Arbitrary Deadlines” has been accepted for publication in Real-time Systems journal. This work is first authored by Ishfaq Hussain and is another collaboration with my former colleagues at CISTER. The article extends our RTNS 2019 paper “Response Time Analysis of Multiframe Mixed-Criticality Systems” that received both an Outstanding Paper Award and a Best Student Paper Award. The RTNS paper presented a schedulability analysis for the multi-frame mixed-criticality model, extending the static and dynamic analysis techniques for mixed-criticality scheduling and the schedulability analysis for multi-frame task systems.

The accepted journal article extends the RTNS paper by generalizing the proposed schedulability analyses from a constrained-deadline task model to the more general, but also more complex, model with arbitrary deadlines. The corresponding optimal priority assignment for our schedulability analysis is also identified. In experiments with synthetic workloads, the proposed analyses are compared in terms of scheduling success ratio, against the frame-agnostic analyses for the corresponding variants of the Vestal model.