Date: Thursday 12 March 2015
Time: 08:30 - 10:00
Location / Room: Meije
Chair:
Sylvian Kaiser, DOCEA Power, FR
Co-Chair:
Sander Stuijk, Eindhoven University of Technology, NL
This session deals with modeling and simulating extra-functional system properties. The first paper presents a framework to accurately model the power and timing of hardware models without requiring a full micro-architectural simulation of the hardware module to extract signal transitions. The second paper presents a method to extend Design Space Exploration (DSE) of systems with Out-of-Order execution by accurately predicting the performance of CPUs with different cache configurations within reasonable time. The third paper is about an approach that constructs a learning-based thermal model for a given (black-box) multi-core processor running a given application mix.
| Time | Label | Presentation Title Authors |
|---|---|---|
| 08:30 | 9.5.1 | DYNAMIC POWER AND PERFORMANCE BACK-ANNOTATION FOR FAST AND ACCURATE FUNCTIONAL HARDWARE SIMULATION Speakers: Dongwook Lee, Lizy Kurian John and Andreas Gerstlauer, The University of Texas at Austin, US Abstract Virtual platform prototypes are widely used for early design space exploration at the system level. There is, however, a lack of accurate and fast power and performance models of hardware components at such high levels of abstraction. In this paper, we present an approach that extends fast functional hardware models with the ability to produce detailed, cycle-level timing and power estimates. Our approach is based on back-annotating behavioral hardware descriptions with a dynamic power and performance model that allows capturing cycle-accurate and data-dependent activity without a significant loss in simulation speed. By integrating with existing high-level synthesis (HLS) flows, back-annotation is fully automated for custom hardware synthesized by HLS. We further leverage state-of-the-art machine learning techniques to synthesize abstract power models, where we introduce a structural decomposition technique to reduce model complexities and increase estimation accuracy. We have applied our back-annotation approach to several industrial-strength design examples under various architecture configurations. Results show that our models predict average power consumption to within 1% and cycle-by-cycle power dissipation to within 10% of a commercial gate-level power estimation tool, all while running several orders of magnitude faster. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 09:00 | 9.5.2 | FAST AND PRECISE CACHE PERFORMANCE ESTIMATION FOR OUT-OF-ORDER EXECUTION Speakers: Roeland Douma, Sebastian Altmeyer and Andy Pimentel, University of Amsterdam, NL Abstract Design space exploration (DSE) is a key ingredient of system-level design, enabling designers to quickly prune the set of possible designs and determine, e.g., the number of the processing cores, the mapping of application tasks to cores, and the core configuration such as the cache organization. High-level performance estimation is a principle component of any system-level DSE: it has to be fast and sufficiently precise. Modern out-of-order architectures with caches pose a significant problem to this performance estimation process, as no simple one-to-one mapping of the number of cache misses and resulting cycle time exists. We present a high-level cache performance-estimation framework for out-of-order processors. Evaluation shows that our prediction method is on average 15 times faster than cycle-accurate simulation, while our estimates only show an average error of below 3.5%, reduce the pessimism of a naive high-level performance estimation by around 66%, and still maintain a high fidelity. Our approach thus enables quick yet accurate performance estimation and extends the applicability of system-level DSE to out-of-order processors with caches. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 09:30 | 9.5.3 | A CALIBRATION BASED THERMAL MODELING TECHNIQUE FOR COMPLEX MULTICORE SYSTEMS Speakers: Devendra Rai and Lothar Thiele, Swiss Federal Institute of Technology in Zurich (ETHZ), CH Abstract A calibration based method to construct fast and accurate thermal models of the state-of-the-art multicore systems is presented. Such models are usually required during Design Space Exploration (DSE) exercises to evaluate various task-to-core mapping, associated scheduling and processor speed-scaling options for their overall impact on the system temperature. Current approaches require modeling the thermal characteristics of the target processor using numerical simulators, which assume accurate information about several critical parameters (e.g., the processor floorplan). Such parameters are not readily available, forcing the system designers to use time and cost intensive, and possibly error-prone techniques such as using heat maps for reverse-engineering such parameters. Additionally, advanced power and temperature management algorithms commonly found in the state-of-the-art processors must also be accurately modeled. This paper proposes a calibration based method for constructing the complete system thermal model of a target processor without requiring any hard-to-get information such as the detailed processor floorplan or system power traces. Taking an example of a sufficiently complex Intel Xeon 8-core processor, we show that our approach yields an accurate thermal model, which is also lightweight both in terms of memory and compute requirements to be practically feasible for DSE over current processors. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 10:00 | IP4-13, 938 | FP-SCHEDULING FOR MODE-CONTROLLED DATAFLOW: A CASE STUDY Speakers: Alok Lele1, Orlando Moreira2 and Kees van Berkel2 1Eindhoven University of Technology, NL; 2Ericsson B.V., NL Abstract Dual-Radio Simultaneous Access (DRSA) is an emerging topic in Software Defined Radio (SDR) in which two SDRs are running simultaneously on a shared hardware, typically a heterogeneous Multi-Processor System-on-Chip (MPSoC). Each SDR has a independent hard latency and/or throughput requirement and needs rigorous timing analysis. Moreover, SDRs are often modeled in enriched variants of dataflow to accommodate the growing dynamic execution of SDRs, making it a challenge to perform timing analysis on them. This paper considers the preemptive Fixed Priority Scheduling (FPS) of SDRs modeled in emph{Mode-Controlled Dataflow}. To the best of our knowledge this is the first attempt on static timing analysis of FPS for a (semi-)dynamic variant of synchronous dataflow. We propose a two-phase algorithm to determine the worst-case response time of an actor. We demonstrate our analysis results for a DRSA case study of two 4G-LTE receivers. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 10:00 | End of session Coffee Break in Exhibition Area Coffee Break in Exhibition AreaOn all conference days (Tuesday to Thursday), coffee and tea will be served during the coffee breaks at the below-mentioned times in the exhibition area. Lunch BreakOn Tuesday and Wednesday, lunch boxes will be served in front of the session room Salle Oisans and in the exhibition area for fully registered delegates (a voucher will be given upon registration on-site). On Thursday, lunch will be served in Room Les Ecrins (for fully registered conference delegates only). Tuesday, March 10, 2015Coffee Break 10:30 - 11:30 Lunch Break 13:00 - 14:30; Keynote session from 13:20 - 14:20 (Room Oisans) sponsored by Mentor Graphics Coffee Break 16:00 - 17:00 Wednesday, March 11, 2015Coffee Break 10:00 - 11:00 Lunch Break 12:30 - 14:30, Keynote lectures from 12:50 - 14:20 (Room Oisans) Coffee Break 16:00 - 17:00 Thursday, March 12, 2015Coffee Break 10:00 - 11:00 Lunch Break 12:30 - 14:00, Keynote lecture from 13:20 - 13:50 Coffee Break 15:30 - 16:00 |