On the performance of non-contiguous allocation for common communication patterns in 2D mesh-connected multicomputers

International Journal of Grid and High Performance Computing

Ababneh

2023

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Single-chip multicore processors and their network on chip interconnection mechanisms have received extensive interest since the early 2000s. The mesh topology is popular in networks on chip. A common issue in mesh is that it can result in high energy consumption and chip temperatures. It has been recently shown that mapping communicating tasks to neighboring cores can reduce communication delays and the associated power consumption and improve throughput. This paper evaluates the contiguous allocation strategy first fit and non-contiguous allocation strategies that attempt to achieve a degree of contiguity among the cores allocated to a job. One of the non-contiguous strategies is a new strategy, referred to as neighbor allocation strategy, which decomposes the job request so that it can be accommodated by free core submeshes and individual cores that have degree of contiguity. The results show that the relative merits of the policies depend on the job's communication pattern.

Section: Simulation Resultsmentioning

confidence: 99%

Section: Simulation Resultsmentioning

confidence: 99%

On Allocation Algorithms for Manycore Systems With Network on Chip

Shdefat

International Journal of Grid and High Performance Computing

Ababneh

2023

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“…Extensive simulation experiments have been conducted to study the effect of all request shapes approach on the performance of the BL allocation strategy. As in previous research (Yoo & Das, 2002;Chang & Mohapatra, 1998;Chiu & Chen, 1999;Ababneh, 2006;Ababneh, 2008;Ababneh, 2001;Ababneh, 2009;Ababneh et al, 2015;Ababneh et al, 2010;Bani-Mohammad & Ababneh, 2013;Bani-Mohammad et al, 2010;Bani-Mohammad et al, 2011;Bani-Mohammad et al, 2015;Bani-Mohammad et al, 2007a;Bani-Mohammad et al, 2006;Bani-Mohammad et al, 2007b;Bani-Mohammad et al, 2009;Lo et al, 1997;Zhu, 1992), the main system performance parameters used are the average turnaround time of jobs and mean system utilization, where the turnaround time of a job is the time that the job spends in the mesh system from arrival to departure, while the system utilization is the percentage of processors that are utilized over time. The important independent variable in the simulation is the system load.…”

Section: Simulation Resultsmentioning

confidence: 99%

“…It is defined as the inverse of the mean inter-arrival time of jobs. Its range of values, from low to heavy loads, has been determined through experimentation with the simulator, allowing each allocation strategy to reach its upper limits of utilization (Ababneh, 2006;Ababneh, 2008;Ababneh, 2001;Ababneh, 2009;Ababneh et al, 2015;Ababneh et al, 2010;Bani-Mohammad & Ababneh, 2013;Bani-Mohammad et al, 2010;Bani-Mohammad et al, 2011;Bani-Mohammad et al, 2015;Bani-Mohammad et al, 2007a;Bani-Mohammad et al, 2006;Bani-Mohammad et al, 2007b;Bani-Mohammad et al, 2009;Lo et al, 1997;Zhu, 1992).…”

Section: Simulation Resultsmentioning

confidence: 99%

An Efficient All Shapes Busy List Processor Allocation Algorithm for 3D Mesh Multicomputers

International Journal of Cloud Applications and Computing

2017

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Contiguous processor allocation is useful for security and accounting reasons. This is due to the allocated jobs are separated from one another, where each sub-mesh of processors is allocated to an exclusive job request, and the allocated sub-mesh has the same size and shape of the requested job. The size and shape constraint leads to high processor fragmentation. Most recent contiguous allocation strategies suggested for 3D mesh-connected multiconputers try all possible orientations of an allocation request when allocation fails for the requested orientation, which reduces processor fragmentation and hence improves system performance. However, none of them considers all shapes of the request in the process of allocation. To generalize this restricted rotation, we propose, in this paper, a new contiguous allocation strategy for 3D mesh-connected multicomputers, referred to as All Shapes Busy List (ASBL for short), which takes into consideration all possible contiguous request shapes when attempting allocation for a job request. ASBL depends on the list of allocated sub-meshes, in the method suggested in (Bani-Mohammad et al., 2006), for selecting an allocated sub-mesh. The performance of the proposed ASBL allocation strategy has been evaluated considering several important scheduling strategies under a variety of system loads based on different job size distributions. The simulation results have shown that the ASBL allocation strategy improves system performance in terms of parameters such as the average turnaround time of jobs and system utilization under all scheduling strategies considered.

“…Each simulation run consists of 1000 completed jobs. Simulation results are averaged over enough independent runs so that the confidence level is 95% that relative errors are below 5% of the means (Bani-Mohammad & Ababneh, 2013;Law & Kelton, 2000). The method used to calculate confidence intervals is called batch means analysis (Al-Dubai et al, 2004;Bani-Mohammad, 2008;ProcSimity, 1997).…”

Section: Performance Evaluationmentioning

confidence: 99%

A New Compacting Non-Contiguous Processor Allocation Algorithm for 2D Mesh Multicomputers

Ababneh

Journal of Information Technology Research

Yassen

2015

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In non-contiguous allocation, a job request can be split into smaller parts that are allocated possibly non-adjacent free sub-meshes rather than always waiting until a single sub-mesh of the requested size and shape is available. Lifting the contiguity condition is expected to reduce processor fragmentation and increase system utilization. However, the distances traversed by messages can be long, and as a result the communication overhead, especially contention, is likely to increase. The extra communication overhead depends on how the allocation request is partitioned and assigned to free sub-meshes. In this paper, a new non-contiguous processor allocation strategy, referred to as Compacting Non-Contiguous Processor Allocation Strategy (CNCPA), is suggested for the 2D mesh multicomputers. In the proposed strategy, a job is compacted into free locations. The selection of the free locations has for goal leaving large free sub-meshes in the system. To evaluate the performance improvement achieved by the proposed strategy and compare it against well-known existing non-contiguous allocation strategies, the authors conducted extensive simulation experiments. The results show that the proposed strategy can improve performance in terms of job turnaround times and system utilization.