In this paper, an energy-efficient scheduling algorithm, called ceiling-based conditional abortable scheduling (CB-CAS) algorithm, is proposed to schedule periodic hard real-time tasks in a non-ideal DVS processor. Based on the schedulability analysis, CBCAS calculates a proper processor speed for task execution so that the energy consumption can be reduced without violating the timing constrai...

In network-based parallel architectures, the issues of fairness, freedom of deadlock due to nite buuers and guaranteed message delivery can aaect not only performance but even more importantly the guarantees that the architecture provides to the users so that they can write correct, race-free portable programs. When blocking communication is assumed, the solutions to these problems can be relat...

While attempting to clarify the confusion concerning the conceptualization of "blocking zeros" in state space in the recent literature, some new observations are made on the relationship between pole-zero cancellation and transmission blocking. An important distinction between uncontrollable and unobservable eigenvalue s is pointed out; and it is argued that the description of a Blocking Zero, ...

Most multiprocessors are multiprogrammed to achieve acceptable response time. Unfortunately, inopportune preemption may significantly degrade the performance of synchronized parallel applications. To address this problem, researchers have developed two principal strategies for concurrent, atomic update of shared data structures: (1) preemption-safe locking and (2) non-blocking (lock-free) algor...

An eecient template for the implementation on distributed-memory multiprocessors of iterated parallel loops, i.e. parallel loops nested in a sequential loop, is presented. The template is explicitly designed to smooth unbalanced processor workloads deriving from loops whose iterations are characterized by highly varying execution times. Experiments conducted shows performance gains w.r.t. HPF-l...

one of the main features of high throughput computing systems is the availability of high power processing resources. cloud computing systems can offer these features through concepts like pay-per-use and quality of service (qos) over the internet. many applications in cloud computing are represented by workflows. quality of service is one of the most important challenges in the context of sche...

Parallel programs running on shared memory multiprocessors coordinate via shared data objects/structures. To ensure the consistency of the shared data structures, programs typically rely on some forms of software synchronisations. Unfortunately typical software synchronisation mechanisms usually result in poor performance because they produce large amounts of memory and interconnection network ...

During the last half-decade, a number of research efforts have centered around developing software for generating automatically tuned matrix multiplication kernels. These include the PHiPAC project and the ATLAS project. The software products of both projects employ brute force to search a parameter space for blockings that accommodate multiple levels of memory hierarchy. We take a different ap...

User-level threads have performance and exibility advantages over both Unix-like processes and kernel threads. However, the performance of user-level threads may su er in multiprogrammed environments, or when threads block in the kernel (e.g., for I/O). These problems can be particularly severe in tasks that communicate frequently using IPC (e.g., multithreaded servers), due to interactions bet...