238 research outputs found
On Benchmarking Embedded Linux Flash File Systems
Due to its attractive characteristics in terms of performance, weight and
power consumption, NAND flash memory became the main non volatile memory (NVM)
in embedded systems. Those NVMs also present some specific
characteristics/constraints: good but asymmetric I/O performance, limited
lifetime, write/erase granularity asymmetry, etc. Those peculiarities are
either managed in hardware for flash disks (SSDs, SD cards, USB sticks, etc.)
or in software for raw embedded flash chips. When managed in software, flash
algorithms and structures are implemented in a specific flash file system
(FFS). In this paper, we present a performance study of the most widely used
FFSs in embedded Linux: JFFS2, UBIFS,and YAFFS. We show some very particular
behaviors and large performance disparities for tested FFS operations such as
mounting, copying, and searching file trees, compression, etc.Comment: Embed With Linux, Lorient : France (2012
Toward a Unified Performance and Power Consumption NAND Flash Memory Model of Embedded and Solid State Secondary Storage Systems
This paper presents a set of models dedicated to describe a flash storage
subsystem structure, functions, performance and power consumption behaviors.
These models cover a large range of today's NAND flash memory applications.
They are designed to be implemented in simulation tools allowing to estimate
and compare performance and power consumption of I/O requests on flash memory
based storage systems. Such tools can also help in designing and validating new
flash storage systems and management mechanisms. This work is integrated in a
global project aiming to build a framework simulating complex flash storage
hierarchies for performance and power consumption analysis. This tool will be
highly configurable and modular with various levels of usage complexity
according to the required aim: from a software user point of view for
simulating storage systems, to a developer point of view for designing, testing
and validating new flash storage management systems
High-level synthesis under I/O Timing and Memory constraints
The design of complex Systems-on-Chips implies to take into account
communication and memory access constraints for the integration of dedicated
hardware accelerator. In this paper, we present a methodology and a tool that
allow the High-Level Synthesis of DSP algorithm, under both I/O timing and
memory constraints. Based on formal models and a generic architecture, this
tool helps the designer to find a reasonable trade-off between both the
required I/O timing behavior and the internal memory access parallelism of the
circuit. The interest of our approach is demonstrated on the case study of a
FFT algorithm
Evaluation of the Performance/Energy Overhead in DSP Video Decoding and its Implications
Video decoding is considered as one of the most compute and energy intensive
application in energy constrained mobile devices. Some specific processing
units, such as DSPs, are added to those devices in order to optimize the
performance and the energy consumption. However, in DSP video decoding, the
inter-processor communication overhead may have a considerable impact on the
performance and the energy consumption. In this paper, we propose to evaluate
this overhead and analyse its impact on the performance and the energy
consumption as compared to the GPP decoding. Our work revealed that the GPP can
be the best choice in many cases due to the a significant overhead in DSP
decoding which may represents 30% of the total decoding energy
DyPS: Dynamic Processor Switching for Energy-Aware Video Decoding on Multi-core SoCs
In addition to General Purpose Processors (GPP), Multicore SoCs equipping
modern mobile devices contain specialized Digital Signal Processor designed
with the aim to provide better performance and low energy consumption
properties. However, the experimental measurements we have achieved revealed
that system overhead, in case of DSP video decoding, causes drastic
performances drop and energy efficiency as compared to the GPP decoding. This
paper describes DyPS, a new approach for energy-aware processor switching (GPP
or DSP) according to the video quality . We show the pertinence of our solution
in the context of adaptive video decoding and describe an implementation on an
embedded Linux operating system with the help of the GStreamer framework. A
simple case study showed that DyPS achieves 30% energy saving while sustaining
the decoding performanc
Performance Evaluation of Flash File Systems
Today, flash memory are strongly used in the embedded system domain. NAND
flash memories are the building block of main secondary storage systems. Such
memories present many benefits in terms of data density, I/O performance, shock
resistance and power consumption. Nevertheless, flash does not come without
constraints: the write / erase granularity asymmetry and the limited lifetime
bring the need for specific management. This can be done through the operating
system using dedicated Flash File Systems (FFSs). In this document, we present
general concepts about FFSs, and implementations example that are JFFS2, YAFFS2
and UBIFS, the most commonly used flash file systems. Then we give performance
evaluation results for these FFSs.Comment: Colloque du GDR SoC-SiP, Paris : France (2012
Functional Validation of AADL Models via Model Transformation to SystemC with ATL
6 pagesInternational audienceIn this paper, we put into action an ATL model transformation in order to automatically generate SystemC models from AADL models. The AADL models represent electronic systems to be embedded into FPGAs. Our contribution allows for an early analytical estimation of energetic needs and a rapid SystemC simulation before implementation. The transformation has been tested to simulate an existing video image processing system embedded into a Xilinx Virtex5 FPGA
An Efficient Power Estimation Methodology for Complex RISC Processor-based Platforms
International audienceIn this contribution, we propose an efficient power estima- tion methodology for complex RISC processor-based plat- forms. In this methodology, the Functional Level Power Analysis (FLPA) is used to set up generic power models for the different parts of the system. Then, a simulation framework based on virtual platform is developed to evalu- ate accurately the activities used in the related power mod- els. The combination of the two parts above leads to a het- erogeneous power estimation that gives a better trade-off be- tween accuracy and speed. The usefulness and effectiveness of our proposed methodology is validated through ARM9 and ARM CortexA8 processor designed respectively around the OMAP5912 and OMAP3530 boards. This efficiency and the accuracy of our proposed methodology is evaluated by using a variety of basic programs to complete media bench- marks. Estimated power values are compared to real board measurements for the both ARM940T and ARM CortexA8 architectures. Our obtained power estimation results pro- vide less than 3% of error for ARM940T processor, 3.5% for ARM CortexA8 processor-based system and 1x faster compared to the state-of-the-art power estimation tools
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