A Sequentially Consistent Multiprocessor Architecture for Out-of-Order Retirement of Instructions

Out-of-order retirement of instructions has been shown to be an effective technique to increase the number of in-flight instructions. This form of runtime scheduling can reduce pipeline stalls caused by head-of-line blocking effects in the reorder buffer (ROB). Expanding the width of the instruction...

ver descrição completa

Detalhes bibliográficos
Autores: Ubal Tena, Rafael, Kaeli, David, Sahuquillo Borrás, Julio|||0000-0001-8630-4846, Petit Martí, Salvador Vicente|||0000-0003-2426-4134, López Rodríguez, Pedro Juan|||0000-0003-4544-955X
Formato: artículo
Fecha de publicación:2012
País:España
Recursos:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/36007
Acesso em linha:https://riunet.upv.es/handle/10251/36007
Access Level:acceso abierto
Palavra-chave:Out-of-order retirement
Multicore processors
Validation buffer
Sequential consistency
ARQUITECTURA Y TECNOLOGIA DE COMPUTADORES
Descrição
Resumo:Out-of-order retirement of instructions has been shown to be an effective technique to increase the number of in-flight instructions. This form of runtime scheduling can reduce pipeline stalls caused by head-of-line blocking effects in the reorder buffer (ROB). Expanding the width of the instruction window can be highly beneficial to multiprocessors that implement a strict memory model, especially when both loads and stores encounter long latencies due to cache misses, and whose stalls must be overlapped with instruction execution to overcome the memory latencies. Based on the Validation Buffer (VB) architecture (a previously proposed out- of-order retirement, checkpoint-free architecture for single processors), this paper proposes a cost-effective, scalable, out-of-order retirement multiprocessor, capable of enforcing sequential consistency without impacting the design of the memory hierarchy or interconnect. Our simulation results indicate that utilizing a VB can speed up both relaxed and sequentially consistent in-order retirement in future multiprocessor systems by between 3 and 20 percent, depending on the ROB size.