527 research outputs found
MORA: an Energy-Aware Slack Reclamation Scheme for Scheduling Sporadic Real-Time Tasks upon Multiprocessor Platforms
In this paper, we address the global and preemptive energy-aware scheduling
problem of sporadic constrained-deadline tasks on DVFS-identical multiprocessor
platforms. We propose an online slack reclamation scheme which profits from the
discrepancy between the worst- and actual-case execution time of the tasks by
slowing down the speed of the processors in order to save energy. Our algorithm
called MORA takes into account the application-specific consumption profile of
the tasks. We demonstrate that MORA does not jeopardize the system
schedulability and we show by performing simulations that it can save up to 32%
of energy (in average) compared to execution without using any energy-aware
algorithm.Comment: 11 page
Energy-Efficient Scheduling for Homogeneous Multiprocessor Systems
We present a number of novel algorithms, based on mathematical optimization
formulations, in order to solve a homogeneous multiprocessor scheduling
problem, while minimizing the total energy consumption. In particular, for a
system with a discrete speed set, we propose solving a tractable linear
program. Our formulations are based on a fluid model and a global scheduling
scheme, i.e. tasks are allowed to migrate between processors. The new methods
are compared with three global energy/feasibility optimal workload allocation
formulations. Simulation results illustrate that our methods achieve both
feasibility and energy optimality and outperform existing methods for
constrained deadline tasksets. Specifically, the results provided by our
algorithm can achieve up to an 80% saving compared to an algorithm without a
frequency scaling scheme and up to 70% saving compared to a constant frequency
scaling scheme for some simulated tasksets. Another benefit is that our
algorithms can solve the scheduling problem in one step instead of using a
recursive scheme. Moreover, our formulations can solve a more general class of
scheduling problems, i.e. any periodic real-time taskset with arbitrary
deadline. Lastly, our algorithms can be applied to both online and offline
scheduling schemes.Comment: Corrected typos: definition of J_i in Section 2.1; (3b)-(3c);
definition of \Phi_A and \Phi_D in paragraph after (6b). Previous equations
were correct only for special case of p_i=d_
ILP-based approaches to partitioning recurrent workloads upon heterogeneous multiprocessors
The problem of partitioning systems of independent constrained-deadline sporadic tasks upon heterogeneous multiprocessor platforms is considered. Several different integer linear program (ILP) formulations of this problem, offering different tradeoffs between effectiveness (as quantified by speedup bound) and running time efficiency, are presented
Power-Aware Real-Time Scheduling upon Identical Multiprocessor Platforms
In this paper, we address the power-aware scheduling of sporadic
constrained-deadline hard real-time tasks using dynamic voltage scaling upon
multiprocessor platforms. We propose two distinct algorithms. Our first
algorithm is an off-line speed determination mechanism which provides an
identical speed for each processor. That speed guarantees that all deadlines
are met if the jobs are scheduled using EDF. The second algorithm is an on-line
and adaptive speed adjustment mechanism which reduces the energy consumption
while the system is running.Comment: The manuscript corresponds to the final version of SUTC 2008
conferenc
Scheduling Techniques for Operating Systems for Medical and IoT Devices: A Review
Software and Hardware synthesis are the major subtasks in the implementation of hardware/software systems. Increasing trend is to build SoCs/NoC/Embedded System for Implantable Medical Devices (IMD) and Internet of Things (IoT) devices, which includes multiple Microprocessors and Signal Processors, allowing designing complex hardware and software systems, yet flexible with respect to the delivered performance and executed application. An important technique, which affect the macroscopic system implementation characteristics is the scheduling of hardware operations, program instructions and software processes. This paper presents a survey of the various scheduling strategies in process scheduling. Process Scheduling has to take into account the real-time constraints. Processes are characterized by their timing constraints, periodicity, precedence and data dependency, pre-emptivity, priority etc. The affect of these characteristics on scheduling decisions has been described in this paper
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