Software Distributed Shared Memory Using the VIPS Coherence Protocol
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
A coherent global address space in a distributed system enables shared memory programming in a much larger scale than in a single multicore processor. The solution is to implement a software distributed shared memory (SWDSM) system since hardware support at this scale is non-existent. However, traditional approaches to coherence in SWDSM systems (centralized via 'active' home-node directories) are inherently unfit for such a scenario. Instead, it is crucial to make decisions locally and avoid the long latency imposed by both network and software message-handlers. This thesis investigates the performance of an SWDSM system with a novel and completely distributed coherence protocol that minimizes long-latency communications common in coherence protocols. More specifically, we propose an approach suitable for data race free programs, based on self-invalidation and self-downgrade inspired by the VIPS cache coherence protocol. This thesis tries to exploit the distributed nature of self-invalidation, self-downgrade by using a passive data classification directory that require no message-handlers, thereby incurring no extra latency when issuing coherence requests. The result is an SWDSM system called SVIPS which maximizes local decision making and allows high parallel performance with minimal coherence traffic between nodes in a distributed system.
Place, publisher, year, edition, pages
2015. , 53 p.
UPTEC IT, ISSN 1401-5749 ; 15002
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-256975OAI: oai:DiVA.org:uu-256975DiVA: diva2:827858
Kaxiras, StefanosBol, Roland