1,720,985 research outputs found
Constrained Power Management: an holistic approach to power management
No full textThe general purpose of operating systems like Linux, thanks to their predisposition to adapt easily to different application contexts, is a common choice for many new generation mobile devices. Being a key feature to improve mobility, energy efficiency has become a high priority design goal, and the implementation of the necessary mechanisms to optimize both power and performances can no longer be separated from the requirements of ease of development, portability and adaptability.
This work presents a formal model to define the problem of power vs performance control. We have proven that a distributed control is particularly suited to meet the goals of both adaptability and portability, without unduly compromising the effectiveness of control and its efficiency.
Starting from the current Linux solution we will advance the proposal for an extension that is better tailored to embedded mobile systems. The proposed solution has been implemented in a new Linux kernel framework named CPM which is competitive in adaptability and ensures better control on performances while still not affecting ease of implementation
BOSP: BarbequeRTRM Open Source Project
No full textThe BarbequeRTRM is a framework being developed at DEI - Politecnico di Milano - under the context of the European Project 2PARMA and it has been partially funded by the EC under the FP7-ICT-248716-2PARMA grant. This framework is the core of an highly modular and extensible run-time resource manager which provide support for an easy integration and management of multiple applications competing on the usage of one (or more) shared MIMD many-core computation devices. The framework design, which exposes different plugin interfaces, provides support for pluggable policies for both resource scheduling and the management of applications coordination and reconfiguration.
Applications integrated with this framework gets “for-free” a suitable instrumentation to support Design-Space-Exploration (DSE) techniques, which could be used to profile application behaviors to either optimize them at design time or support the identification of optimal QoS requirements goals as well as their run-time monitoring.
Suitable platform abstraction layers, built on top of Linux kernel interfaces, allows an easily porting of the framework on different platforms and its integration with specific execution environments such as the Android run-time.
Based on all these features the framework allows an easily coding of resource management policies which support an optimized assignment of resources to demanding applications considering:
- application properties, e.g. run-time requirements, operating modes and relative priorities,
- resources availability and state, e.g. power and thermal conditions
- tunable run-time optimization goals, e.g. power reduction, energy optimization, reconfiguration overheads minimization and overall performances maximization.
An initial version of the proposed framework is already available and actively developed as an OpenSource project, the Barbeque OpenSource Project (BOSP), which defines a new approach to develop a System-Wide RTRM supporting a comprehensive set of advanced features, such as:
- a hierarchical and distributed control
- the exploitation of design-time information
- a rich multi-objective optimization strategy
- a portable and modular design based on a set of tunable policies
Effective runtime resource management using linux control groups with the BarbequeRTRM framework
Full text linkThe extremely high technology process reached by silicon manufacturing (smaller than 32nm) has led to production of computational platforms and SoC, featuring a considerable amount of resources. Whereas from one side such multi- and many-core platforms show growing performance capabilities, from the other side they are more and more affected by power, thermal, and reliability issues. Moreover, the increased computational capabilities allows congested usage scenarios with workloads subject to mixed and time-varying requirements. Effective usage of the resources should take into account both the application requirements and resources availability, with an arbiter, namely a resource manager in charge to solve the resource contention among demanding applications.
Current operating systems (OS) have only a limited knowledge about application-specific behaviors and their time-varying requirements. Dedicated system interfaces to collect such inputs and forward them to the OS (e.g., its scheduler) are thus an interesting research area that aims at integrating the OS with an ad hoc resource manager. Such a component can exploit efficient low-level OS interfaces and mechanisms to extend its capabilities of controlling tasks and system resources. Because of the specific tasks and timings of a resource manager, this component can be easily and effectively developed as a user-space extension lying in between the OS and the controlled application.
This article, which focuses on multicore Linux systems, shows a portable solution to enforce runtime resource management decisions based on the standard control groups framework. A burst and a mixed workload analysis, performed on a multicore-based NUMA platform, have reported some promising results both in terms of performance and power saving
Predictive Models for Multimedia Applications Power Consumption Based on Use-Case and OS Level Analysis
No full textPower management at any abstraction level is a key
issue for many mobile multimedia and embedded applications.
In this paper a design workflow to generate system-level power
models will be presented, tailored to support quantitative runtime
power optimization policies to be implemented within
an operating system. The approach we followed to derive
power models is strongly use-case oriented. Starting from a
comprehensive general and accurate model of a representative
architecture for embedded applications (including a multi core
MPSoC, accelerators, interfaces and peripherals), a methodology
to derive compact models is presented, based upon the distinctive
characteristics of the selected use cases. The methodology to
generate such model, whose exploitation is foreseen within a
power manager working at the OS level, is the focus of the paper.
The value and accuracy of the approach is quantitatively and
statistically justified through extensive experiments carried out
on a development board designed for multimedia applications
Power management using constraints in multi-dimensional parameter space
No full textTecnica per la riduzione del consumo di potenza in sistemi embedded, operando a livello di sistema operativoAn embodiment of a method and system are provided for
managing both system resources and power consumption of a
computer system, involving different layers of the system: an
application layer, a middle layer where the operating system is running and where a power manager is provided, and a
hardware layer used for communicating with the hardware
devices. Hardware devices have different operating modes
which provide distinct trade-offs between performances and
power consumption. Performance requirements defined at
the level of the application layer, as well as the device power
status of the system, set constraints on the system resources.
The middle layer power manager may be in charge of retriev
ing performance requirements in form of constraints set on
System parameters, aggregating these constraints oppor
tunely and communicating corresponding information to the
device drivers which may then select a best operating mode
A Step Toward Exploiting Task Affinity in Multi-core Architectures to Improve Determinism of Real-time Applications
No full textCPM: A Cross-Layer Framework to EfficientlySupport Distributed Resources Management
No full textResource management, and especially power management, is a key aspect for the success of modern battery supplied multimedia devices. This class of devices are usually based on SoCs with a wide range of heterogeneous subsystems, competing for shared resources while offering several power control mechanisms. Many of these mechanisms require suitable software support to be exploited effectively. Unfortunately, real commercial systems focusing on mobile multimedia exposes a software layer composed by a collection of fairly independent local optimization policies, each focusing on a specific device or subsystem. This paper presents CPM, a cross-layer model and framework to support system wide resource management. The main goals of this framework are to efficiently support the aggregation of applications' QoS requirements and to provide a dynamic, system-wide, and multi-objective optimization to coordinate devices' local policies. A real solution, which is well integrated within the existing Linux kernels, has been developed and evaluated to asses its negligible overhead
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