Time Donating Barrier for efficient task scheduling in competitive multicore systems

Abstract

Nowadays, co-locating multithreaded applications on a multicore system has increasingly become a common case in cloud data centers, where multiple threads generally compete for computing resources. These competitive environments may suffer problems of system throughput and fairness caused by barrier operations in multithreaded applications. This is because most implementations of the barrier synchronization are based on the spin-thenblock mechanism in which spinning-waiting threads probably waste computing resources and relinquish cores to other co-running applications after they are blocked. This paper wants to find a new and intuitive way to improve the efficiency of barrier in competitive environments, and answer the question: Can we leverage the timeslices of waiting threads to accelerate barrier operations? Targeting this question, we propose a novel barrier synchronization mechanism named Tidon (Time Donating Barrier). The basic idea of Tidon is to donate the timeslices of waiting threads to their preempted, laggard siblings in order to accelerate barrier operations, different from traditional static spinning and blocking. We implement Tidon based on the GNU OpenMP runtime library (libgomp) and Linux kernel with new, lightweight system calls. Our evaluation with various sets of co-running applications demonstrates that the advantages of Tidon include (1) alleviating the performance degradation of barrier-intensive applications (e.g. improving the performance by up to a factor of 17.9 and 2.3 compared to the default barrier implementation of OpenMP in Completely Fair Scheduler and Balance

A Review on Dynamic Resource Allocation Based on Lease Types in Cloud Environment

“…NIST specify five characteristics of cloud computing [9]: On-demand self-service involves customers using a web site or similar control panel interface to provision computing resources such as additional computers, network bandwidth or user email accounts, without requiring human interaction between customers and the vendor.…”

“…Equally Spread Current Execution Algorithm: Equally spread current execution algorithm [9] process handle with priorities. it distribute the load randomly by checking the size and transfer the load to that virtual machine which is light ly loaded or handle that task easy and take less time , and give maximize throughput.…”

“…Throttled Load Balancing Algorithm: Throttled algorithm [9] is completely based on virtual machine. In this client first requesting the load balancer to check the right virtual machine which access that load easily and perform the operations which is give by the client or user.…”