The document summarizes a proposed dynamic task scheduling algorithm for multicore engine control units in automobiles. The algorithm aims to maximize CPU utilization, minimize preemption overhead and average waiting time, and ensure all tasks meet real-time deadlines. It involves calculating the slack (period - worst case execution time) for each task and assigning dynamic priorities based on least slack. Tasks are dispatched to local queues on each core based on availability. When new tasks arrive, slacks are compared to order tasks and potentially migrate tasks between cores to reduce deadline misses. Simulation results show the dynamic approach achieves 100% CPU utilization and ensures all tasks meet deadlines, whereas the static priority approach results in some tasks missing deadlines.
Integrating fault tolerant scheme with feedback control scheduling algorithm ...ijics
In order to provide Quality of Service (QoS) in open and unpredictable environment, Feedback based
Control Scheduling Algorithm (FCSA) is designed to keep the processor utilization at the scheduling
utilization bound. FCSA controls CPU utilization by assigning task periods that optimize overall control
performance, meeting deadlines even if the task execution time is unpredictable and through performance
control feedback loop. Current FCSA doesn’t ensure Fault Tolerance (FT) while providing QoS in terms of
CPU utilization and resource management. In order to assure that tasks should meet their deadlines even
in the presence of faults, a FT scheme has to be integrated at control scheduling co-design level. This paper
presents a novel approach on integrating FT scheme with FCSA for real time embedded systems. This
procedure is especially important for control scheduling co-design of embedded systems.
D1.2 analysis and selection of low power techniques, services and patternsBabak Sorkhpour
Goal: SAFEPOWER has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 687902.
SAFEPOWER’s goal is to enable the development of low power mixed-criticality systems through the provision of a reference architecture, platforms and tools to facilitate the development, testing, and validation of these kinds of systems according to the market needs
It is expected that the SAFEPOWER reference architecture and platforms will enable the integration and partitioning of mixed-criticality applications on a single device while reducing the total power consumption by 50%, compared to the non-integrated multi-chip implementation. To address this goal, SAFEPOWER needs to address a number of technology development challenges, that will afterwards be applied to the main project outputs, namely the SAFEPOWER low power reference architecture, the platforms and tools for the development, testing, and validation of low power mixed criticality systems.
PROJECT PARTNER(S):IKERLAN, S. Coop.CAF Signalling, S.L.fent Innovative Software SolutionsImperas Software Ltd.Kungliga Tekniska Högskolan (Royal Institute of Technology)SAAB ABUniversität Siegen
Methods: Railway Engineering, Energy Efficiency, Multi-Core Systems, Safety-Critical Systems, Industrial Safety, Avionics, MPSOCs, NoC, Fault Tolerance, Scheduling Theory, Power Management, Dependable Systems, MIXED CRITICALITY, predictable architectures and communication, Low Power Techniques, ENERGY MINIMIZATION TECHNIQUES, Energy and Power efficiency, Low power multicore embedded systems, Fault Isolation, hypervisor
Social media links:
a.Twitter : https://twitter.com/SAFEPOWER_H2020
b.Linkdin : https://www.linkedin.com/groups/7045467
d. Website : http://safepower-project.eu/
d.ResearchGate : https://www.researchgate.net/project/SAFEPOWER
Run time dynamic partial reconfiguration using microblaze soft core processor...eSAT Journals
aydeshmukh@gmail.com
Abstract
DSP Application requires a fast computations & flexibility of the design. Partial Reconfiguration (PR) is an advanced technique,
which improves the flexibility of FPGAs by allowing portions of a design to be reconfigured at runtime by overwriting parts of the
configuration memory. In this paper we are using microblaze soft core processor & ICAP Port to reconfigure the FPGA at runtime.
ICAP is accessed through a light-weight custom IP which requires bit stream length, go, and done signal to interface to a system that
provides partial bit stream data. The partial bit stream is provided by the processor system by reading the partial bit files from the
compact flash card. Our targeted DSP application is matrix multiplication; we are reconfiguring design by changing partial modules
at run time. To change the partial bit stream we interfaces a microblaze Soft processor & using a UART interface.ISE13.1 &
PlanAhead is used for partial reconfiguration of FPGA .EDK is used for microblaze soft processor design & ICAP Interface .The
simulation is done using Chip Scope Logic Analyzer & the complete hardware implementation is done on Xilinx VIRTEX -6 ML605
Platform.
Keywords — PlanAhead, EDK, Dynamic partial reconfiguration, ICAP, Matrix multiplication, Chipscope pro analysis,
DSP application, Microblaze processor
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Integrating fault tolerant scheme with feedback control scheduling algorithm ...ijics
In order to provide Quality of Service (QoS) in open and unpredictable environment, Feedback based
Control Scheduling Algorithm (FCSA) is designed to keep the processor utilization at the scheduling
utilization bound. FCSA controls CPU utilization by assigning task periods that optimize overall control
performance, meeting deadlines even if the task execution time is unpredictable and through performance
control feedback loop. Current FCSA doesn’t ensure Fault Tolerance (FT) while providing QoS in terms of
CPU utilization and resource management. In order to assure that tasks should meet their deadlines even
in the presence of faults, a FT scheme has to be integrated at control scheduling co-design level. This paper
presents a novel approach on integrating FT scheme with FCSA for real time embedded systems. This
procedure is especially important for control scheduling co-design of embedded systems.
D1.2 analysis and selection of low power techniques, services and patternsBabak Sorkhpour
Goal: SAFEPOWER has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 687902.
SAFEPOWER’s goal is to enable the development of low power mixed-criticality systems through the provision of a reference architecture, platforms and tools to facilitate the development, testing, and validation of these kinds of systems according to the market needs
It is expected that the SAFEPOWER reference architecture and platforms will enable the integration and partitioning of mixed-criticality applications on a single device while reducing the total power consumption by 50%, compared to the non-integrated multi-chip implementation. To address this goal, SAFEPOWER needs to address a number of technology development challenges, that will afterwards be applied to the main project outputs, namely the SAFEPOWER low power reference architecture, the platforms and tools for the development, testing, and validation of low power mixed criticality systems.
PROJECT PARTNER(S):IKERLAN, S. Coop.CAF Signalling, S.L.fent Innovative Software SolutionsImperas Software Ltd.Kungliga Tekniska Högskolan (Royal Institute of Technology)SAAB ABUniversität Siegen
Methods: Railway Engineering, Energy Efficiency, Multi-Core Systems, Safety-Critical Systems, Industrial Safety, Avionics, MPSOCs, NoC, Fault Tolerance, Scheduling Theory, Power Management, Dependable Systems, MIXED CRITICALITY, predictable architectures and communication, Low Power Techniques, ENERGY MINIMIZATION TECHNIQUES, Energy and Power efficiency, Low power multicore embedded systems, Fault Isolation, hypervisor
Social media links:
a.Twitter : https://twitter.com/SAFEPOWER_H2020
b.Linkdin : https://www.linkedin.com/groups/7045467
d. Website : http://safepower-project.eu/
d.ResearchGate : https://www.researchgate.net/project/SAFEPOWER
Run time dynamic partial reconfiguration using microblaze soft core processor...eSAT Journals
aydeshmukh@gmail.com
Abstract
DSP Application requires a fast computations & flexibility of the design. Partial Reconfiguration (PR) is an advanced technique,
which improves the flexibility of FPGAs by allowing portions of a design to be reconfigured at runtime by overwriting parts of the
configuration memory. In this paper we are using microblaze soft core processor & ICAP Port to reconfigure the FPGA at runtime.
ICAP is accessed through a light-weight custom IP which requires bit stream length, go, and done signal to interface to a system that
provides partial bit stream data. The partial bit stream is provided by the processor system by reading the partial bit files from the
compact flash card. Our targeted DSP application is matrix multiplication; we are reconfiguring design by changing partial modules
at run time. To change the partial bit stream we interfaces a microblaze Soft processor & using a UART interface.ISE13.1 &
PlanAhead is used for partial reconfiguration of FPGA .EDK is used for microblaze soft processor design & ICAP Interface .The
simulation is done using Chip Scope Logic Analyzer & the complete hardware implementation is done on Xilinx VIRTEX -6 ML605
Platform.
Keywords — PlanAhead, EDK, Dynamic partial reconfiguration, ICAP, Matrix multiplication, Chipscope pro analysis,
DSP application, Microblaze processor
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
ISPRS: COMPARISON OF MULTIPLE IMUs IN AN EXPERIMENTAL FLIGHT TESTLaura Samsó, MSc
Laura Samsó, Mariano Wis, Ismael Colomina
GP-IMU-Bench experiment consists of simultaneous acquisition of data from multiple inertial units under the same
dynamic and static conditions. To accomplish those conditions, all the sensors are fixed on a platform that is directly
mounted into an airplane. This configuration permits all the inertial units to be able to sense the same movements. The
aim of this experiment is to obtain a set of data that allows establishing some comparisons among the IMUs that the IG
owns. The results of this experiment are very helpful to evaluate which is the best kind of IMU to be mounted on any
remote sensor.
In order to get these datasets, a series of HW and SW modifications were applied on IG’s TAG system for acquiring
the data from the IMUs simultaneously. Therefore, this paper goes through these modifications made on the system
with a more detailed description of the experiment. Some preliminary results of the comparison are shown.
The timing behavior of the OS must be predictable - services of the OS: Upper bound on the execution time!
2. OS must manage the timing and scheduling
OS possibly has to be aware of task deadlines;
(unless scheduling is done off-line).
3. The OS must be fast
The note is compiled with reference from many sites and According to the syllabus of Real Time System (6th semester CSIT). Drive deep to the never ending knowledge.
For Induction motor is a system that works at their speed, nevertheless there are applications at which the speed operations are needed. The control of range of speed of induction motor techniques is available. The robust control is used with induction motor and the performance of the system with the controller will be improved. The mathematical model to the controller, which were coded in MATLAB. The modeling and controller will be shown by the conditions of robustness of be less than one.
Design and Development of Arm-Based Control System for Nursing Bed IJCSES Journal
This paper introduces a kind of ARM embedded system as the control systemof the nursing bed.The
embedded control system takes the ARM9 S3C2440 chip as the core of data processing. The design ofthe
control system includes hardware design, software design and PC monitoring system design.
REAL-TIME SCHEDULING ALGORITHMS FOR WIRELESS SENSOR NETWORKcsijjournal
In Recent era, researchers attention is get magnetize towards a widely used technology known as a wireless sensor networks (WSNs) used in the many of applications related to variety of fields including military, healthcare
monitoring, biological, home, vehicular monitoring, infrastructure monitoring, building energy monitoring and industrial sensing. Many of applications in WSNs are real time applications that are requested to run in real time
way. To support such real time applications we need Real Time Operating System (RTOS) which provides logically correct results and also deadline has to be met. This paper presents an overview of existing scheduling
algorithms which helps to schedule tasks in real time systems. Next, we discuss work in sensornet operating system (OS) design. Then, the specialties what sensornet OS should posses are discussed in detail. At last, we
proposed Micro Controller OS-II (µC/OS-II) with Earliest Deadline First (EDF) algorithm.
AN EFFICIENT HYBRID SCHEDULER USING DYNAMIC SLACK FOR REAL-TIME CRITICAL TASK...ijesajournal
Task intensive electronic control units (ECUs) in automotive domain, equipped with multicore processors ,
real time operating systems (RTOSs) and various application software, should perform efficiently and time
deterministically. The parallel computational capability offered by this multicore hardware can only be
exploited and utilized if the ECU application software is parallelized. Having provided with such
parallelized software, the real time operating system scheduler component should schedule the time critical
tasks so that, all the computational cores are utilized to a greater extent and the safety critical deadlines
are met. As original equipment manufacturers (OEMs) are always motivated towards adding more
sophisticated features to the existing ECUs, a large number of task sets can be effectively scheduled for
execution within the bounded time limits. In this paper, a hybrid scheduling algorithm has been proposed,
that meticulously calculates the running slack of every task and estimates the probability of meeting
deadline either being in the same partitioned queue or by migrating to another. This algorithm was run and
tested using a scheduling simulator with different real time task models of periodic tasks . This algorithm
was also compared with the existing static priority scheduler, which is suggested by Automotive Open
Systems Architecture (AUTOSAR). The performance parameters considered here are, the % of core
utilization, average response time and task deadline missing rate. It has been verified that, this proposed
algorithm has considerable improvements over the existing partitioned static priority scheduler based on
each performance parameter mentioned above.
ENERGY EFFICIENT SCHEDULING FOR REAL-TIME EMBEDDED SYSTEMS WITH PRECEDENCE AN...IJCSEA Journal
Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling and Dynamic Frequency Scaling allow us to adjust supply voltage and processor frequency to adapt to the workload demand for better energy management. Usually, higher processor voltage and frequency leads to higher system throughput while energy reduction can be obtained using lower voltage and frequency. Many real-time scheduling algorithms have been developed recently to reduce energy consumption in the portable devices that use voltage scalable processors. For a real-time application, comprising a set of real-time tasks with precedence and resource constraints executing on a distributed system, we propose a dynamic energy efficient scheduling algorithm with weighted First Come First Served (WFCFS) scheme. This also considers the run-time behaviour of tasks, to further explore the idle periods of processors for energy saving. Our algorithm is compared with the existing Modified Feedback Control Scheduling (MFCS), First Come First Served (FCFS), and Weighted scheduling (WS) algorithms that uses Service-Rate-Proportionate (SRP) Slack Distribution Technique. Our proposed algorithm achieves about 5 to 6 percent more energy savings and increased reliability over the existing ones.
SCHEDULING DIFFERENT CUSTOMER ACTIVITIES WITH SENSING DEVICEijait
Most periodic tasks are assigned to processors using partition scheduling policy after checking feasibility conditions. A new approach is proposed for scheduling different activities with one periodic task within the system. In this paper, control strategies are identified for allocating different types of tasks (activities) to
individual computing elements like Smartphone or microphones. In our simulation model, each periodic task generates an aperiodic tasks are taken into consideration. Different sets of periodic tasks and aperiodic tasks are scheduled together. This new approach proves that when all different activities are
scheduled with one periodic tasks leads to better performance.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
ISPRS: COMPARISON OF MULTIPLE IMUs IN AN EXPERIMENTAL FLIGHT TESTLaura Samsó, MSc
Laura Samsó, Mariano Wis, Ismael Colomina
GP-IMU-Bench experiment consists of simultaneous acquisition of data from multiple inertial units under the same
dynamic and static conditions. To accomplish those conditions, all the sensors are fixed on a platform that is directly
mounted into an airplane. This configuration permits all the inertial units to be able to sense the same movements. The
aim of this experiment is to obtain a set of data that allows establishing some comparisons among the IMUs that the IG
owns. The results of this experiment are very helpful to evaluate which is the best kind of IMU to be mounted on any
remote sensor.
In order to get these datasets, a series of HW and SW modifications were applied on IG’s TAG system for acquiring
the data from the IMUs simultaneously. Therefore, this paper goes through these modifications made on the system
with a more detailed description of the experiment. Some preliminary results of the comparison are shown.
The timing behavior of the OS must be predictable - services of the OS: Upper bound on the execution time!
2. OS must manage the timing and scheduling
OS possibly has to be aware of task deadlines;
(unless scheduling is done off-line).
3. The OS must be fast
The note is compiled with reference from many sites and According to the syllabus of Real Time System (6th semester CSIT). Drive deep to the never ending knowledge.
For Induction motor is a system that works at their speed, nevertheless there are applications at which the speed operations are needed. The control of range of speed of induction motor techniques is available. The robust control is used with induction motor and the performance of the system with the controller will be improved. The mathematical model to the controller, which were coded in MATLAB. The modeling and controller will be shown by the conditions of robustness of be less than one.
Design and Development of Arm-Based Control System for Nursing Bed IJCSES Journal
This paper introduces a kind of ARM embedded system as the control systemof the nursing bed.The
embedded control system takes the ARM9 S3C2440 chip as the core of data processing. The design ofthe
control system includes hardware design, software design and PC monitoring system design.
REAL-TIME SCHEDULING ALGORITHMS FOR WIRELESS SENSOR NETWORKcsijjournal
In Recent era, researchers attention is get magnetize towards a widely used technology known as a wireless sensor networks (WSNs) used in the many of applications related to variety of fields including military, healthcare
monitoring, biological, home, vehicular monitoring, infrastructure monitoring, building energy monitoring and industrial sensing. Many of applications in WSNs are real time applications that are requested to run in real time
way. To support such real time applications we need Real Time Operating System (RTOS) which provides logically correct results and also deadline has to be met. This paper presents an overview of existing scheduling
algorithms which helps to schedule tasks in real time systems. Next, we discuss work in sensornet operating system (OS) design. Then, the specialties what sensornet OS should posses are discussed in detail. At last, we
proposed Micro Controller OS-II (µC/OS-II) with Earliest Deadline First (EDF) algorithm.
AN EFFICIENT HYBRID SCHEDULER USING DYNAMIC SLACK FOR REAL-TIME CRITICAL TASK...ijesajournal
Task intensive electronic control units (ECUs) in automotive domain, equipped with multicore processors ,
real time operating systems (RTOSs) and various application software, should perform efficiently and time
deterministically. The parallel computational capability offered by this multicore hardware can only be
exploited and utilized if the ECU application software is parallelized. Having provided with such
parallelized software, the real time operating system scheduler component should schedule the time critical
tasks so that, all the computational cores are utilized to a greater extent and the safety critical deadlines
are met. As original equipment manufacturers (OEMs) are always motivated towards adding more
sophisticated features to the existing ECUs, a large number of task sets can be effectively scheduled for
execution within the bounded time limits. In this paper, a hybrid scheduling algorithm has been proposed,
that meticulously calculates the running slack of every task and estimates the probability of meeting
deadline either being in the same partitioned queue or by migrating to another. This algorithm was run and
tested using a scheduling simulator with different real time task models of periodic tasks . This algorithm
was also compared with the existing static priority scheduler, which is suggested by Automotive Open
Systems Architecture (AUTOSAR). The performance parameters considered here are, the % of core
utilization, average response time and task deadline missing rate. It has been verified that, this proposed
algorithm has considerable improvements over the existing partitioned static priority scheduler based on
each performance parameter mentioned above.
ENERGY EFFICIENT SCHEDULING FOR REAL-TIME EMBEDDED SYSTEMS WITH PRECEDENCE AN...IJCSEA Journal
Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling and Dynamic Frequency Scaling allow us to adjust supply voltage and processor frequency to adapt to the workload demand for better energy management. Usually, higher processor voltage and frequency leads to higher system throughput while energy reduction can be obtained using lower voltage and frequency. Many real-time scheduling algorithms have been developed recently to reduce energy consumption in the portable devices that use voltage scalable processors. For a real-time application, comprising a set of real-time tasks with precedence and resource constraints executing on a distributed system, we propose a dynamic energy efficient scheduling algorithm with weighted First Come First Served (WFCFS) scheme. This also considers the run-time behaviour of tasks, to further explore the idle periods of processors for energy saving. Our algorithm is compared with the existing Modified Feedback Control Scheduling (MFCS), First Come First Served (FCFS), and Weighted scheduling (WS) algorithms that uses Service-Rate-Proportionate (SRP) Slack Distribution Technique. Our proposed algorithm achieves about 5 to 6 percent more energy savings and increased reliability over the existing ones.
SCHEDULING DIFFERENT CUSTOMER ACTIVITIES WITH SENSING DEVICEijait
Most periodic tasks are assigned to processors using partition scheduling policy after checking feasibility conditions. A new approach is proposed for scheduling different activities with one periodic task within the system. In this paper, control strategies are identified for allocating different types of tasks (activities) to
individual computing elements like Smartphone or microphones. In our simulation model, each periodic task generates an aperiodic tasks are taken into consideration. Different sets of periodic tasks and aperiodic tasks are scheduled together. This new approach proves that when all different activities are
scheduled with one periodic tasks leads to better performance.
CS 301 Computer ArchitectureStudent # 1 EID 09Kingdom of .docxfaithxdunce63732
CS 301 Computer Architecture
Student # 1
E
ID: 09
Kingdom of Saudi Arabia Royal Commission at Yanbu Yanbu University College Yanbu Al-Sinaiyah
Student # 2
H
ID: 09
Kingdom of Saudi Arabia Royal Commission at Yanbu Yanbu University College Yanbu Al-Sinaiyah
1
1. Introduction
High-performance processor design has recently taken two distinct approaches. One approach is to increase the execution rate by increasing the clock frequency of the processor or by reducing the execution latency of the operations. While this approach is important, much of its performance gain comes as a consequence of circuit and layout improvements and is beyond the scope of this research. The other approach is to directly exploit the instruction-level parallelism (ILP) in the program and to issue and execute multiple operations concurrently. This approach requires both compiler and microarchitecture support.
Traditional processor designs that issue and execute at most one operation per cycle are often called scalar designs. Static and dynamic scheduling techniques have been used to achieve better-than scalar performance by issuing and executing more than one operation per cycle. While Johnson[7] defines a superscalar processor as a design that achieves better-than scalar performance, popular usage of this term refers exclusively to those processors that use dynamic scheduling techniques. For clarity, we use instruction-level parallel processors to refer to the general class of processors that execute more than one operation per cycle of the computer both at the personal level, or the level of a small network of computers to do not require more of these types.
The primary static scheduling technique uses the compiler to determine sets of operations that have their source operands ready and have no dependencies within the set. These operations can then be scheduled within the same instruction subject only to hardware resource limits. Since each of the operations in an instruction is guaranteed by the compiler to be independent, the hardware is able to is- sue and execute these operations directly with no dynamic analysis. These multi-operation instructions are very long in comparison with traditional single-operation instructions and processors using .
TIME CRITICAL MULTITASKING FOR MULTICORE MICROCONTROLLER USING XMOS® KITijesajournal
This paper presents the research work on multicore microcontrollers using parallel, and time critical
programming for the embedded systems. Due to the high complexity and limitations, it is very hard to work
on the application development phase on such architectures. The experimental results mentioned in the
paper are based on xCORE multicore microcontroller form XMOS®
. The paper also imitates multi-tasking
and parallel programming for the same platform. The tasks assigned to multiple cores are executed
simultaneously, which saves the time and energy. The relative study for multicore processor and multicore
controller concludes that micro architecture based controller having multiple cores illustrates better
performance in time critical multi-tasking environment. The research work mentioned here not only
illustrates the functionality of multicore microcontroller, but also express the novel technique of
programming, profiling and optimization on such platforms in real time environments.
A tricky task scheduling technique to optimize time cost and reliability in m...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Integrating Fault Tolerant Scheme With Feedback Control Scheduling Algorithm ...ijics
In order to provide Quality of Service (QoS) in open and unpredictable environment, Feedback based
Control Scheduling Algorithm (FCSA) is designed to keep the processor utilization at the scheduling
utilization bound. FCSA controls CPU utilization by assigning task periods that optimize overall control
performance, meeting deadlines even if the task execution time is unpredictable and through performance
control feedback loop.
Reinforcement learning based multi core scheduling (RLBMCS) for real time sys...IJECEIAES
Embedded systems with multi core processors are increasingly popular because of the diversity of applications that can be run on it. In this work, a reinforcement learning based scheduling method is proposed to handle the real time tasks in multi core systems with effective CPU usage and lower response time. The priority of the tasks is varied dynamically to ensure fairness with reinforcement learning based priority assignment and Multi Core MultiLevel Feedback queue (MCMLFQ) to manage the task execution in multi core system
Time critical multitasking for multicoreijesajournal
This paper presents the research work on multicore microcontrollers using parallel, and time critical
programming for the embedded systems. Due to the high complexity and limitations, it is very hard to work
on the application development phase on such architectures. The experimental results mentioned in the
paper are based on xCORE multicore microcontroller form XMOS®. The paper also imitates multi-tasking
and parallel programming for the same platform. The tasks assigned to multiple cores are executed
simultaneously, which saves the time and energy. The relative study for multicore processor and multicore
controller concludes that micro architecture based controller having multiple cores illustrates better
performance in time critical multi-tasking environment. The research work mentioned here not only
illustrates the functionality of multicore microcontroller, but also express the novel technique of
programming, profiling and optimization on such platforms in real time environments.
LEARNING SCHEDULER PARAMETERS FOR ADAPTIVE PREEMPTIONcscpconf
An operating system scheduler is expected to not allow processor stay idle if there is any
process ready or waiting for its execution. This problem gains more importance as the numbers
of processes always outnumber the processors by large margins. It is in this regard that
schedulers are provided with the ability to preempt a running process, by following any
scheduling algorithm, and give us an illusion of simultaneous running of several processes. A
process which is allowed to utilize CPU resources for a fixed quantum of time (termed as
timeslice for preemption) and is then preempted for another waiting process. Each of these
'process preemption' leads to considerable overhead of CPU cycles which are valuable resource
for runtime execution. In this work we try to utilize the historical performances of a scheduler
and predict the nature of current running process, thereby trying to reduce the number of
preemptions. We propose a machine-learning module to predict a better performing timeslice
which is calculated based on static knowledge base and adaptive reinforcement learning based
suggestive module. Results for an "adaptive timeslice parameter" for preemption show good
saving on CPU cycles and efficient throughput time.
Learning scheduler parameters for adaptive preemptioncsandit
An operating system scheduler is expected to not al
low processor stay idle if there is any
process ready or waiting for its execution. This pr
oblem gains more importance as the numbers
of processes always outnumber the processors by lar
ge margins. It is in this regard that
schedulers are provided with the ability to preempt
a running process, by following any
scheduling algorithm, and give us an illusion of si
multaneous running of several processes. A
process which is allowed to utilize CPU resources f
or a fixed quantum of time (termed as
timeslice for preemption) and is then preempted for
another waiting process. Each of these
'process preemption' leads to considerable overhead
of CPU cycles which are valuable resource
for runtime execution. In this work we try to utili
ze the historical performances of a scheduler
and predict the nature of current running process,
thereby trying to reduce the number of
preemptions. We propose a machine-learning module t
o predict a better performing timeslice
which is calculated based on static knowledge base
and adaptive reinforcement learning based
suggestive module. Results for an "adaptive timesli
ce parameter" for preemption show good
saving on CPU cycles and efficient throughput time.
Similar to DYNAMIC TASK SCHEDULING ON MULTICORE AUTOMOTIVE ECUS (20)
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
An Approach to Detecting Writing Styles Based on Clustering Techniquesambekarshweta25
An Approach to Detecting Writing Styles Based on Clustering Techniques
Authors:
-Devkinandan Jagtap
-Shweta Ambekar
-Harshit Singh
-Nakul Sharma (Assistant Professor)
Institution:
VIIT Pune, India
Abstract:
This paper proposes a system to differentiate between human-generated and AI-generated texts using stylometric analysis. The system analyzes text files and classifies writing styles by employing various clustering algorithms, such as k-means, k-means++, hierarchical, and DBSCAN. The effectiveness of these algorithms is measured using silhouette scores. The system successfully identifies distinct writing styles within documents, demonstrating its potential for plagiarism detection.
Introduction:
Stylometry, the study of linguistic and structural features in texts, is used for tasks like plagiarism detection, genre separation, and author verification. This paper leverages stylometric analysis to identify different writing styles and improve plagiarism detection methods.
Methodology:
The system includes data collection, preprocessing, feature extraction, dimensional reduction, machine learning models for clustering, and performance comparison using silhouette scores. Feature extraction focuses on lexical features, vocabulary richness, and readability scores. The study uses a small dataset of texts from various authors and employs algorithms like k-means, k-means++, hierarchical clustering, and DBSCAN for clustering.
Results:
Experiments show that the system effectively identifies writing styles, with silhouette scores indicating reasonable to strong clustering when k=2. As the number of clusters increases, the silhouette scores decrease, indicating a drop in accuracy. K-means and k-means++ perform similarly, while hierarchical clustering is less optimized.
Conclusion and Future Work:
The system works well for distinguishing writing styles with two clusters but becomes less accurate as the number of clusters increases. Future research could focus on adding more parameters and optimizing the methodology to improve accuracy with higher cluster values. This system can enhance existing plagiarism detection tools, especially in academic settings.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
DYNAMIC TASK SCHEDULING ON MULTICORE AUTOMOTIVE ECUS
1. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
DOI : 10.5121/vlsic.2014.5601 1
DYNAMIC TASK SCHEDULING ON MULTICORE
AUTOMOTIVE ECUS
Geetishree Mishra1
, K S Gurumurthy2
1
BMS College of Engineering, Bangalore, India,
2
Reva Intitute of Technology, Bangalore, India
ABSTRACT
Automobile manufacturers are controlled by stringent govt. regulations for safety and fuel emissions and
motivated towards adding more advanced features and sophisticated applications to the existing electronic
system. Ever increasing customer’s demands for high level of comfort also necessitate providing even more
sophistication in vehicle electronics system. All these, directly make the vehicle software system more
complex and computationally more intensive. In turn, this demands very high computational capability of
the microprocessor used in electronic control unit (ECU). In this regard, multicore processors have
already been implemented in some of the task rigorous ECUs like, power train, image processing and
infotainment. To achieve greater performance from these multicore processors, parallelized ECU software
needs to be efficiently scheduled by the underlaying operating system for execution to utilize all the
computational cores to the maximum extent possible and meet the real time constraint. In this paper, we
propose a dynamic task scheduler for multicore engine control ECU that provides maximum CPU
utilization, minimized preemption overhead, minimum average waiting time and all the tasks meet their
real time deadlines while compared to the static priority scheduling suggested by Automotive Open Systems
Architecture (AUTOSAR).
KEYWORDS
OEM, ECU, Multicore, Scheduling, AUTOSAR.
1. INTRODUCTION
Electronic Control Units (ECUs) fulfill the objectives and requirements of a modern automobile
which is designed to be safer, more comfortable and fuel efficient. Therefore the number of ECUs
has been increased continuously over the years. Advanced functionalities demand higher
computational capabilities from ECUs. Multicore processors have emerged to be the current
processing unit not only for high-end servers but also for embedded control systems [10, 11].
Multicore processor features with parallel processing, compact chip size and lower power
consumption. Performance is improved, the amount of processes per core is reduced and better
reliability of the on-chip communication is assured by the multicore implementation. In the
current scenario, OEMs are moving towards multicore to exploit parallelism, to accommodate
more functions on one ECU and distribute them across the computational cores [1, 3]. In effect,
some of the task intensive ECUs catering to telematics, infotainment and power train are already
upgraded with multicore processors. Performance optimization of such multicore ECUs can be
2. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
2
achieved by utilizing parallelism effectively for which, numerous runnables should be efficiently
scheduled for each core [3,4]. The operating system should have an efficient scheduling
mechanism to schedule the tasks without corrupting the shared data and without leaving any CPU
core idle at any running instant [5]. Without an optimal schedule, there can be considerable
variations in average task response times and logical correctness of the results [6]. Such
anomalies can cause instabilities in the physical system leading to performance degradation and
even safety hazards. In this paper, a hybrid dynamic scheduler is proposed for the most task
intensive engine control ECU.
2. CASE STUDY - ENGINE CONTROL UNIT
In this work, engine control unit is chosen as the target ECU for task scheduling, as it has
maximum number tasks to be executed both periodic and event driven and it has already been
implemented with multicore. Engine control unit is usually connected to a large cluster of sensors
like, intake air temperature sensor, engine coolant temperature sensor, intake manifold absolute
pressure (MAP) sensor, mass air flow sensor, throttle position sensor, crankshaft speed sensor,
camshaft sensor and knock sensor. It is connected to various actuators like idle speed motor,
electronic throttle body, fuel pressure regulator and fuel injector and delivery control. Basically
those are stepper motors and solenoids directly connected to the ECU [7]. For each sensor, there
has to be a task to receive the sensory signal after being conditioned, a task to process it as
required according to the control algorithm and another task to send appropriate signal to the
intended actuator. Each task has a large number of threads to be executed sequentially with data
dependency. Independent threads are executed in parallel by multiple cores. For each engine
ECU functionality like, air charge management, engine cooling management, battery
management, air fuel management or on-board diagnostics, a large number of inputs to be
received, parameters and local variables to be managed and many outputs are expected to be
delivered. Because of high level of interaction between the control functions, the shared data are
required to be protected efficiently [4, 6]. Three different task schedulers used are, synchronous
scheduler, asynchronous scheduler and background scheduler [7]. Synchronous scheduler is used
for tasks that need to be executed at certain crank teeth. Asynchronous scheduler also called the
time-base scheduler is executed just after the power up scheduler initialization. Background tasks
run, when the CPU is idle basically they are busy-wait loops [12, 13]. Besides that, various
interrupt service routines are executed to respond to hardware events. Right from the engine start
till stop of the vehicle, engine ECU runs with its software of several 1000 lines of code.
3. AUTOSAR ON MULTICORE SCHEDULING
According to AUTOSAR 4.0, there are certain limitations on multicore software implementation.
• The scheduling algorithms strictly assign tasks statically to cores to ensure deterministic
response for the real time critical tasks.
• The resource algorithm is not supported across cores. Resources can be shared between
tasks that are allocated to the same core but not among tasks/ISRs which are bound to
different cores.
OSEK counter and auto started alarms can be used to implement task activation mechanism. The
task synchronization issue is addressed by implementing schedule table. The Autosar schedule
3. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
3
table shown in Figure.1. has certain defined set of expiry points. Each expiry point has certain
tasks to be activated, settings to be done for some events and offset from the start of the schedule
table [8]. OSEK counter drives the iteration over these expiry points on the schedule table. So one
tick on the counter corresponds to one tick on the schedule table. Constraints apply to the delays
between adjacent expiry points and the delay to the logical end of the schedule table. According
to Autosar, the hard real time safety critical tasks are scheduled statically to computational cores
as per the fixed priority assigned. In this static priority scheduling approach, the tasks have to be
partitioned well with the order of criticality and an appropriate priority assignment scheme has to
be adopted to assign priorities prior to run time, which is always a tedious job. The computational
cores are sometimes underutilized and the lower priority tasks often miss their deadline though
not the most safety critical ones. In this paper, a global dynamic priority approach has been
explored.
Figure.1. Schedule table for AUTOSAR ECU
4. THE PROPOSED SCHEDULER MODEL
Figure.2. Scheduler model
4. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
4
The scheduler model shown in above Fig.2. has a combination of both global and partitioned
queue architecture. All the tasks arrive at the global queue, where the slack is calculated for each
and priorities are assigned dynamically. The task with least slack gets highest priority. Then the
three tasks pass on to three partitioned queues to utilize all the available cores. When a new task
arrives at the partitioned queue in the presence of previous task, a comparison happens between
their slack and tasks are arranged in ascending order of their slack in the queue with an effort to
meet the deadlines. In this simulation setup, a task set of 10 number of tasks are considered for an
asynchronous or timebase scheduler. The task attributes for the ith task are: {releasing instant ri,
WCET wi and period pi }, where WCET is the worst case execution time. Precedence constraint
is imposed on some of the tasks based on dependency. A tri-core processor implementation is
considered for these tasks to be scheduled for. The scheduled tasks are released for execution by
the dispatcher task which is characterized by a dispatching table of definite duration.
5. SCHEDULING PROBLEM
The scheduling problems are categorized by notation (α|β|γ) proposed by Graham and Blazewicz
[14,15]. This notation consists of three parts. The first part ‘α’ describes the processor
environment, the second part ‘β’ describes the task characteristics and constraints of the
scheduling problem and the last part ‘γ’ denotes the optimality criterion. In this simulation set up,
for a three processor environment, α=3. Since all the tasks are release time constrained and they
are periodic, period is the implied deadline for each instance and precedence constraint is also
imposed on some of the tasks, β=|release time, precedence & deadline constraint| and γ= Cmax,
the maximum completion time to achieve an optimal schedule.
6. WORKING OF THE PROPOSED MINIMUM SLACK FIRST ALGORITHM
At a new arriving instant at global queue,
• Calculate the slack of each task arrived .Where, Slack= Period-WCET.
• Sort the tasks in increasing order of their slack i,e S1< S2 <S3…….Sn.
• Assign priorities to these tasks dynamically by giving highest priority to the task with least
slack.
• If precedence constraint imposed on the task, Pass the task to a partitioned queue preferably
to the one where its precedence task has been allocated.
• If no precedence constraint, pass that task to a local queue based on early availability of that
CPU core.
• If :
the no. of tasks arrived at the global queue at a particular instant is > the no. of CPU
cores,
o Compare the total WCET of all the tasks at each partitioned queue.
o Assign the first task in the remaining list at global queue to the core that has least WCET.
• Else:
wait for the next new arriving instant.
At the local partitioned queue,
• If: new task arrives in the presence of previous task,
o If the precedence task of the new arrival is the last task waiting in the queue, no
comparison required.
5. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
5
o Else
Compare the slack of the new task with the WCET of the previous task.
If: S new arrival < WCET previous task + Remaining WCET running task & Sprevious task> WCETnew
arrival ,
• Swap the waiting position of these tasks in the queue.
Else if : Snew arrival < WCETprevious task + Remaining WCETrunning task & Sprevious task<
WCETnew arrival ,
• Get the tasknew to migrate to another local queue whose CPU core is expected to
be available early, getting information from the global queue.
7. TASK ATTRIBUTES TABLE
Table.1. Task attributes table
The task attributes table given in above table. 1 has release time Ri, worst case execution time
WCET, period and static priorities assigned for each of the ten tasks considered [2, 9]. These are
the parameters used for static priority scheduling. In addition to these parameters, the precedence
constraints are considered for dynamic priority scheduling. The slack is the calculated parameter
based on which dynamic priorities are assigned. For example, at 0th
instant, four number of tasks
i,e T1, T3, T5 and T7 are released. So there could be only four levels of priorities that can be
assigned. These priorities are assigned at the global queue to dispatch the tasks to the local
partitioned queues based on their corresponding core’s early availabilities. The first instance of all
the tasks according to minimum slack based dynamic scheduling is shown in the last column of
the attributes table.
8. SEQUENCER TABLE AS PER STATIC PRIORITY
Figure.2. Sequencer table
6. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
6
Fig.2 shows a sequencer table for the tasks to be executed in three computational cores in an
expected sequence as it is given. At every single unit of time the scheduler has to take the
decision in favor of three highest priority tasks among the ready list of tasks arrived as well as
tasks with remaining execution time. In the priority list, the smallest number indicates highest
priority for the most frequent task.
Figure. 3. Simulation result
9. IMPLEMENTATION OF DYNAMIC SCHEDULER AND RESULTS
Figure. 4. Simulation result
The simulation results are shown in the above fig. 3 and fig. 4. These result graphs are Gantt
charts of ten number of tasks being scheduled for three computational cores. Fig. 3 shows the
Gantt chart results of the simulation of static priority scheduling. In this simulation, few
noticeable features are there. Tasks T6, T9 and T10 being assigned with least priorities, are not
7. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
7
getting scheduled and have missed their deadlines even for the first instance. T3 has migrated
from core3 to core2 to complete its WCET after being preempted by T2. Based on the parameter
attributes and constraints imposed on the tasks, both the static and the dynamic algorithms have
run through the global and partitioned queues one after the other. Fig. 4 shows the Gantt chart
results of the simulation of dynamic priority based minimum slack first scheduling. At every
arrival instant at the global queue, slack for each task is calculated and dynamic priorities are
assigned. For this dynamic priority scheduling, precedence constraints have been imposed on
certain tasks. Tasks with the precedence constraints are mostly collocated at a CPU core. At every
arrival instant at the partitioned queue, the slack of the new task is compared with the total WCET
of previous tasks and the currently running task. Either the tasks are sorted in ascending order of
their slack and scheduled for execution or tasks have been preempted and migrated to other
available core in case there is a probability of missing the deadlines. In the result Gantt chart, T6
has migrated from core2 to core3. All the tasks have satisfied their precedence constraints and all
have met with their deadlines. None of the CPU cores is idle at any point of time. So 100% CPU
utilization is achieved within the simulation duration. To minimize the preemption overhead, the
tasks are allowed to continue their execution unless there is a probability of missing the deadline.
Table 2 given below shows the number of periodic instances of each of the 10 tasks within the
simulation duration for both the static and dynamic scheduling and Table 3 shows the comparison
of performance parameters based on the results out of both static and dynamic scheduling run for
the given task set.
Table 2: Tasks with no of instances
Scheduling Methods T1 T2 T3 T4 T5 T6 T7 T8 T9 T10
Static 3 3 2 4 4 0 2 1 0 0
Dynamic 2 2 2 2 2 1 2 1 1 1
Table 3: parameter comparison
10. CONCLUSION
In this paper, a dynamic task scheduling algorithm has been proposed for multicore Engine
control ECU of Automotive electronic system. Engine control ECU being a safety critical, hard
real time system and highly task intensive, the stringent requirement is, all the tasks have to meet
their deadlines. Fixed static priority and partitioned task scheduling for multicore ECUs have
been suggested by AUTOSAR. While adhering to it, there is always a challenge in assigning
priorities to the tasks and high level of difficulty in partitioning the tasks by which certain CPU
cores remain under utilized [3, 8]. In this work, a model taskset with appropriate time attributes
has been tested both with static priority scheduling and the proposed dynamic priority algorithm,
where slack is the utilizing parameter. The performance parameters are compared for the results
of both the algorithms. It is observed that, in static priority scheduling, CPUs are highly utilized
8. International Journal of VLSI design & Communication Systems (VLSICS) Vol.5, No.6, December 2014
8
by higher priority tasks only and the lowest priority tasks are consistently missing their deadlines
while in dynamic priority case, there is a significant improvement in terms of missing deadlines
and there is a fair allocation across all priorities. Average response time, number of pre-emption
and migration have been improved considerably. Since slack is considered to assign dynamic
priorities and to calculate the relative deadlines, unless there is a probability of missing the
deadline, the task does not get preempted or migrated to other core. So the context switching
overhead is also reduced.
REFERENCES
[1] Yu Hua, Lei Rao, Xue Liu, Dan Feng “Co-operative and Efficient Real-Time Scheduling for
Automotive Communications”. IEEE international conference on Distributed Computing Systems
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[2] Aurélien Monot, Nicolas Navet, Bernard Bavoux, and Françoise Simonot-Lion, “Multisource
Software on Multicore Automotive ECUs—Combining Runnable Sequencing”, IEEE Transactions
on Industrial Electronics, Vol. 59, No. 10, pp 3934-3942, October 2012
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