An Implementation of Partitioned Scheduling Scheme for Hard Real-Time Tasks in Multicore Linux with Fair Share for Linux Tasks

The correctness of a hard real-time system depends its ability to meet all its deadlines. Existing real-time systems use either a pure real-time scheduler or a real-time scheduler embedded as a real-time scheduling class in the scheduler of an operating system (OS). Existing implementations of schedulers in multicore systems that support real-time and non-real-time tasks, permit the execution of non-real-time tasks in all the cores with priorities lower than those of real-time tasks, but interrupts and softirqs associated with these non-real-time tasks can execute in any core with priorities higher than those of real-time tasks. As a result, the execution overhead of real-time tasks is quite large in these systems, which, in turn, affects their runtime. In order that the hard real-time tasks can be executed in such systems with minimal interference from other Linux tasks, we propose, in this paper, an integrated scheduler architecture, called SchedISA, which aims to considerably reduce the execution overhead of real-time tasks in these systems. In order to test the efficacy of the proposed scheduler, we implemented partitioned earliest deadline first (P-EDF) scheduling algorithm in SchedISA on Linux kernel, version 3.8, and conducted experiments on Intel core i7 processor with eight logical cores. We compared the execution overhead of real-time tasks in the above implementation of SchedISA with that in SCHED_DEADLINE's P-EDF implementation, which concurrently executes real-time and non-real-time tasks in Linux OS in all the cores. The experimental results show that the execution overhead of real-time tasks in the above implementation of SchedISA is considerably less than that in SCHED_DEADLINE. We believe that, with further refinement of SchedISA, the execution overhead of real-time tasks in SchedISA can be reduced to a predictable maximum, making it suitable for scheduling hard real-time tasks without affecting the CPU share of Linux tasks.

Pricing and Policy Problems in the Northeast Fluid Milk Industry

This article documents the need for reform of milk pricing in the Northeast. The New York price gouging law can be recast as a fair share law. This new milk policy “kills two birds with one stone.” It corrects regional inequities in raw milk pricing by reforming the pricing of milk at retail by limiting and redistributing excessive retail margins to farmers and consumers. The fair share policy relieves allocative price inefficiency, improves the performance of the federal milk market order pool, and the general performance of the Northeast dairy farming and fluid milk industries.

Highway user fees: updated data needed to determine whether all users pay their fair share.

Mode of access: Internet.

A study of the generalised max–min fair rate allocation for ABR control in ATM

In the rate-based flow control for ATM Available Bit Rate service, fairness is an important requirement, i.e. each flow should be allocated a fair share of the available bandwidth in the network. Max–min fairness, which is widely adopted in ATM, is appropriate only when the minimum cell rates (MCRs) of the flows are zero or neglected. Generalised max–min (GMM) fairness extends the principle of the max–min fairness to accommodate MCR. In this paper, we will discuss the formulation of the GMM fair rate allocation, propose a centralised algorithm, analyse its bottleneck structure and develop an efficient distributed explicit rate allocation algorithm to achieve the GMM fairness in an ATM network. The study in this paper addresses certain theoretical and practical issues of the GMM fair rate allocation.

Fair flow control of ABR service by per-VC virtual queuing

In this paper, a rate-based flow control scheme based upon per-VC virtual queuing is proposed for the Available Bit Rate (ABR) service in ATM. In this scheme, each VC in a shared buffer is assigned a virtual queue, which is a counter. To achieve a specific kind of fairness, an appropriate scheduler is applied to the virtual queues. Each VC's bottleneck rate (fair share) is derived from its virtual cell departure rate. This approach of deriving a VC's fair share is simple and accurate. By controlling each VC with respect to its virtual queue and queue build-up in the shared buffer, network congestion is avoided. The principle of the control scheme is first illustrated by max–min flow control, which is realised by scheduling the virtual queues in round-robin. Further application of the control scheme is demonstrated with the achievement of weighted fairness through weighted round robin scheduling. Simulation results show that with a simple computation, the proposed scheme achieves the desired fairness exactly and controls network congestion effectively.

The taxation of multinational banks : alternative apportionment through a unitary taxation regime aligning with economic reality

The taxation of multinational banks currently is governed by the general principles of international tax. However, it is arguable that there are characteristics exclusive to multinational banks that may warrant the consideration of a separate taxing regime. This article argues that because of the unique nature of multinational banks, the traditional international tax rules governing jurisdiction to tax and allocation of income do not produce a result which is optimal, as it does not reflect economic reality. That is, the current system does not produce a result that accurately reflects the economic source of the income or the location of the economic activity. The suggested alternative is unitary taxation using global formulary apportionment. Formulary apportionment is considered as an alternative that reflects economic reality by recognising the unique nature of multinational banks and allocating the income to the location of the economic activity. The unique nature of multinational banking is recognised in the fact that formulary apportionment does not attempt to undertake a transactional division of a highly integrated multinational entity. Rather, it allocates income to the jurisdictions based on an economically justifiable formula. Starting from this recognition, the purpose of this article is to demonstrate that formulary apportionment is a theoretically superior (or optimal) model for the taxation of multinational banks. An optimal regime, for the purposes of this article, is considered to be one that distributes the taxing rights in an equitable manner between the relevant jurisdictions, while, simultaneously allowing decisions of the international banks to be tax neutral. In this sense, neutrality is viewed as an economic concept and equity is regarded as a legal concept. A neutral tax system is one in which tax rules do not affect economic choices about commercial activities. Neutrality will ideally be across jurisdictions as well as across traditional and non-traditional industries. The primary focus of this article is jurisdictional neutrality. A system that distributes taxing rights in an equitable manner between the relevant jurisdictions ensures that each country receives its fair share of tax revenue. Given the increase in multinational banking, jurisdictions should be concerned that they are receiving their fair share. Inter-nation equity is concerned with re-determining the proper division of the tax base among countries. Richard and Peggy Musgrave argue that sharing of the tax base by countries of source should be seen as a matter of inter-nation equity requiring international cooperation. The rights of the jurisdiction of residency will also be at issue. To this extent, while it is agreed that inter-nation equity is an essential attribute to an international tax regime, there is no universal agreement as to how to achieve it. The current system attempts to achieve such equity through a combined residency and source regime, with the transfer pricing rules used to apportion income between the relevant jurisdictions. However, this article suggests, that as an alternative to the current regime, equity would be achieved through formulary apportionment. Opposition to formulary apportionment is generally based on the argument that it is not a theoretically superior (or optimal) model because of the implementation difficulties. Yet these are two separate issues. As such, this article is divided into two core parts. The first part examines the theoretical soundness of the formulary apportionment model concluding that it is theoretically superior to the arm’s length pricing requirement of the traditional transfer pricing regime. The second part examines the practical implications of accepting formulary apportionment as an optimal model with a view to disclosing the issues that arise when a formulary apportionment regime is adopted. Prior to an analysis of the theoretical and practical application of formulary apportionment to multinational banks, the unique nature of these banks is considered. The article concludes that, while there are significant implementation, compliance, and enforcement issues to overcome, the unitary taxation model may be theoretically superior to the current arm’s length model which applies to multinational banks. This conclusion is based on the unitary taxation model providing greater alignment with the unique features of these banks.

The Owner Share scheduler for a distributed system

In large distributed systems, where shared resources are owned by distinct entities, there is a need to reflect resource ownership in resource allocation. An appropriate resource management system should guarantee that resource's owners have access to a share of resources proportional to the share they provide. In order to achieve that some policies can be used for revoking access to resources currently used by other users. In this paper, a scheduling policy based in the concept of distributed ownership is introduced called Owner Share Enforcement Policy (OSEP). OSEP goal is to guarantee that owner do not have their jobs postponed for longer periods of time. We evaluate the results achieved with the application of this policy using metrics that describe policy violation, loss of capacity, policy cost and user satisfaction in environments with and without job checkpointing. We also evaluate and compare the OSEP policy with the Fair-Share policy, and from these results it is possible to capture the trade-offs from different ways to achieve fairness based on the user satisfaction. © 2009 IEEE.

Three essays on banks trading activities

With a fair share of the blame for the subprime crisis pointing to banks' extensive involvement in trading, this thesis examines three closely related issues. The first essay shows that regulatory capital arbitrage, insolvency risk, and non-interest income are all important motivations for banks to become involved in trading. The second essay support the widely held perception that trading activities such as off-balance sheet derivatives, securitization, and assets sales all are making banks more opaque. With banks' business model changing from ''originate and hold'' to ''originate, repackage, and sell'', the last essay show that trading channel exist and it has weakened the effectiveness of monetary policy transmission through banks' capital and lending channel.

Tamworth Regional Council Social Plan 2006

The Tamworth Regional Social Plan is a document for collaborative planning involving the three spheres of government, the community and commercial sectors, with the aim of enhancing the quality and fairness of life in Tamworth. The Plan is a way of identifying needs and priorities for community facilities and services for Tamworth. The Social Plan reflects Council’s ongoing commitment to the people of the Tamworth Region and, in particular, the social needs and aspirations of our community. The Local Government (General) Amendment (Community and Social Plans) Regulation 1998 grew out of the 1996 NSW Social Justice Directions Statement “Fair Go, Fair Share, Fair Say” which committed the Department of Local Government to ensuring government services are responsive to community needs and diversity. The regulation is designed to:- • Improve Councils’ ability to take account of community needs when formulating their management plans; • Assist Councils to provide or advocate for appropriate and accessible services/facilities; and • Increase the community’s ability to monitor Council efforts in addressing community needs over time. The Local Government (General) Regulation 1999 requires that all councils develop a community/social plan and that all plans be prepared in accordance with guidelines issued by the Department. While Council has a broad function of providing leadership for Tamworth, it is not the only group responsible for providing community services. Developing the Social Plan has required cooperation with various State and Federal agencies as well as with Tamworth’s community groups and agencies.

Infrastructure Disputes Shape Future of Streaming Media

In November 2010, tension between Internet infrastructure companies boiled over in a dispute between content distribution network (CDN) Level 3 and Internet service provider (ISP) Comcast. Level 3, a distribution partner of Netflix, accused Comcast of violating the principles of net neutrality when the ISP increased distribution fees for carrying high bandwidth services. Comcast justified its actions by stating that the price increase was standard practice and argued Level 3 was trying to avoid paying its fair share. The dispute exemplifies the growing concern over the rising costs of streaming media services. The companies facing these inflated infrastructure costs are CDNs (Level 3, Equinix, Limelight, Akamai, and Voxel), companies that host streaming media content on server farms and distribute the content to a variety of carriers, and ISPs (Comcast, Time Warner, Cox, and AT&T), the cable and phone companies that provide “last mile” service to paying customers. Both CDNs and ISPs are lobbying government regulators to keep their costs at a minimum. The outcome of these disputes will influence the cost, quality, and legal status of streaming media.

Tax transparency can work for companies if they do it right

The Tax Transparency Package released by the European Commission last week comes amid global moves by the G20 and others to make it more difficult for companies to avoid paying their fair share of tax. But as serious information sharing plans are hammered out between nations around the world, the Australian government is considering protecting the privacy of some of Australia’s richest people, diluting transparency measures aimed at private companies.

On the Efficiency and Fairness of Transmission Control Loops: A Case for Exogenous Losses

We postulate that exogenous losses-which are typically regarded as introducing undesirable "noise" that needs to be filtered out or hidden from end points-can be surprisingly beneficial. In this paper we evaluate the effects of exogenous losses on transmission control loops, focusing primarily on efficiency and convergence to fairness properties. By analytically capturing the effects of exogenous losses, we are able to characterize the transient behavior of TCP. Our numerical results suggest that "noise" resulting from exogenous losses should not be filtered out blindly, and that a careful examination of the parameter space leads to better strategies regarding the treatment of exogenous losses inside the network. Specifically, we show that while low levels of exogenous losses do help connections converge to their fair share, higher levels of losses lead to inefficient network utilization. We draw the line between these two cases by determining whether or not it is advantageous to hide, or more interestingly introduce, exogenous losses. Our proposed approach is based on classifying the effects of exogenous losses into long-term and short-term effects. Such classification informs the extent to which we control exogenous losses, so as to operate in an efficient and fair region. We validate our results through simulations.

Exogenous-Loss Awareness in Queue Management: Toward Global Fairness

For a given TCP flow, exogenous losses are those occurring on links other than the flow's bottleneck link. Exogenous losses are typically viewed as introducing undesirable "noise" into TCP's feedback control loop, leading to inefficient network utilization and potentially severe global unfairness. This has prompted much research on mechanisms for hiding such losses from end-points. In this paper, we show through analysis and simulations that low levels of exogenous losses are surprisingly beneficial in that they improve stability and convergence, without sacrificing efficiency. Based on this, we argue that exogenous loss awareness should be taken into account in any AQM design that aims to achieve global fairness. To that end, we propose an exogenous-loss aware Queue Management (XQM) that actively accounts for and leverages exogenous losses. We use an equation based approach to derive the quiescent loss rate for a connection based on the connection's profile and its global fair share. In contrast to other queue management techniques, XQM ensures that a connection sees its quiescent loss rate, not only by complementing already existing exogenous losses, but also by actively hiding exogenous losses, if necessary, to achieve global fairness. We establish the advantages of exogenous-loss awareness using extensive simulations in which, we contrast the performance of XQM to that of a host of traditional exogenous-loss unaware AQM techniques.

Performance models of storage contention in cloud environments

We propose simple models to predict the performance degradation of disk requests due to storage device contention in consolidated virtualized environments. Model parameters can be deduced from measurements obtained inside Virtual Machines (VMs) from a system where a single VM accesses a remote storage server. The parameterized model can then be used to predict the effect of storage contention when multiple VMs are consolidated on the same server. We first propose a trace-driven approach that evaluates a queueing network with fair share scheduling using simulation. The model parameters consider Virtual Machine Monitor level disk access optimizations and rely on a calibration technique. We further present a measurement-based approach that allows a distinct characterization of read/write performance attributes. In particular, we define simple linear prediction models for I/O request mean response times, throughputs and read/write mixes, as well as a simulation model for predicting response time distributions. We found our models to be effective in predicting such quantities across a range of synthetic and emulated application workloads.