ETD system

Electronic theses and dissertations repository

 

Tesi etd-11102014-154250


Thesis type
Tesi di laurea magistrale
Author
BELLI, ROBERTO
URN
etd-11102014-154250
Title
Optimizing MPI one-sided synchronization mechanisms on Cray's Cascade HPC systems
Struttura
INFORMATICA
Corso di studi
INFORMATICA E NETWORKING
Commissione
relatore Prof. Danelutto, Marco
tutor Prof. Hoefler, Torsten
controrelatore Prof. Coppola, Massimo
Parole chiave
  • HPC
  • RMA
  • one sided
  • MPI
  • Synchronization
  • Networking
Data inizio appello
05/12/2014;
Consultabilità
completa
Riassunto analitico
In this work we proposed Notified Access a new communication model that targets RDMA networks. <br><br>Our focus was on optimizing producer-consumer computations, avoiding to over synchronize processes in point-to-point communications when it&#39;s not needed. We proposed a communication model in which a notification can be coupled with a single Remote Memory Access (RMA). In our model the target of an RMA operation is directly notified after the completion of a notified operation. This approach, avoiding the use of other synchronization primitives, minimizes synchronization latencies while using full hardware offload typical of high-performance networks. In order to demonstrate lower overheads than other point-to-point synchronization mechanisms, we implemented it in an open source MPI-3 library. <br><br>We evaluated the performances of our implementation in a ping-pong benchmark, a computation/communication overlap benchmark and in three real-world applications: a pipeline stencil, a tree-based reduce and a task based Cholesky factorization.<br><br>Our analysis shows that Notified Access is a valuable primitive for any RMA system and furthermore we show that the required hardware feature are already available in multiple state-of-the-art high-performance networks.
File