Luiz Rodolpho Monnerat

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In this paper we introduce a page-based Lazy Release Consistency protocol called ADSM that constantly and efficiently adapts to the applications' sharing patterns. Adaptation in ADSM is based on our dynamic categorization of the type of sharing experienced by each page. Pages can be categorized as falsely-shared, migratory, or pro-ducer/consumer(s).(More)
Distributed hash tables (DHTs) have been used in a variety of applications, but most DHTs so far have opted to solve lookups with multiple hops, which sacrifices performance in order to keep little routing information and minimize maintenance traffic. In this paper, we introduce D1HT, a novel single hop DHT that is able to maximize performance with(More)
We discuss the performance of Petrobras production Kirchhoff prestack seismic migration on a cluster of 64 GPUs and 256 CPU cores. Porting and optimization of the application hot spot (98.2% of a single CPU core execution time) to a single GPU reduces total execution time by a factor of 36 on a control run. We then argue against the usual practice of(More)
—Efficiently locating information in large-scale distributed systems is a challenging problem to which Peer-to-Peer (P2P) Distributed Hash Tables (DHTs) can provide a highly scalable and cost-effective solution. However, there is very little experience on using DHTs in performance sensitive environments such as High Performance Computing (HPC) datacenters,(More)
We describe the computational characteristics of the Kirchhoff prestack seismic migration currently used in daily production runs at Petrobras and its port to novel architectures. Fully developed in house, this portable and fault tolerant application has high sequential and parallel efficiency, with parallel scalability tested up to 8192 processors on the(More)
International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited. Abstract This paper describes performance results(More)
—Distributed Hash Tables (DHTs) have been used in several applications, but most DHTs have opted to solve lookups with multiple hops, to minimize bandwidth costs while sacrificing lookup latency. This paper presents D1HT, which has a peer-to-peer and self-organizing architecture and is the first DHT that maximizes lookup performance with reasonable(More)
In this paper, we discuss the porting strategy and the achieved performance of Petrobras production code that implements Kirchhoff prestack time and depth seismic migration algorithms on a cluster of 64 GPUs and 256 CPU cores. The time migration of a real-world survey was 20 times faster in the full cluster with GPUs than in the full cluster without GPUs.(More)
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