Jason Duell

The Lam/Mpi Checkpoint/Restart Framework: System-Initiated Checkpointing

As high performance clusters continue to grow in size and popularity, issues of fault tolerance and reliability are becoming limiting factors on application scalability. To address these issues, we present the design and implementation of a system for providing coordinated checkpointing and rollback recovery for MPI-based parallel applications. Our approach integrates the Berkeley Lab BLCR kernel-level process checkpoint system with the LAM implementation of MPI through a defined checkpoint/restart interface. Checkpointing is transparent to the application, allowing the system to be used for cluster maintenance and scheduling reasons as well as for fault tolerance. Experimental results show negligible communication performance impact due to the incorporation of the checkpoint support capabilities into LAM/MPI.

A performance analysis of the Berkeley UPC compiler

Unified Parallel C (UPC) is a parallel language that uses a Single Program Multiple Data (SPMD) model of parallelism within a global address space. The global address space is used to simplify programming, especially on applications with irregular data structures that lead to fine-grained sharing between threads. Recent results have shown that the performance of UPC using a commercial compiler is comparable to that of MPI [7]. In this paper we describe a portable open source compiler for UPC. Our goal is to achieve a similar performance while enabling easy porting of the compiler and runtime, and also provide a framework that allows for extensive optimizations. We identify some of the challenges in compiling UPC and use a combination of micro-benchmarks and application kernels to show that our compiler has low overhead for basic operations on shared data and is competitive, and sometimes faster than, the commercial HP compiler. We also investigate several communication optimizations, and show significant benefits by hand-optimizing the generated code.

Requirements for Linux Checkpoint/Restart

This document has 4 main objectives: (1) Describe data to be saved and restored during checkpoint/restart; (2) Describe how checkpoint/restart is used within the context of the Scalable Systems environment, and MPI applications; (3) Identify issues for a checkpoint/restart implementation; and (4) Sketch the architecture of a checkpoint/restart implementation.

Performance evaluation of two emerging media processors: VIRAM and Imagine

This work presets two emerging media microprocessors, VIRAM and Imagine, and compares the implementation strategies and performance results of these unique architectures. VIRAM is a complete system on a chip which uses PIM technology to combine vector processing with embedded DRAM. Imagine is a programmable streaming architecture with a specialized memory hierarchy designed for computationally intensive data-parallel codes. First, we preset a simple and effective approach for understanding and optimizing vector/stream applications. Performance results are then presented from a number of multimedia benchmarks and a computationally intensive scientific kernel. We explore the complex interactions between programming paradigms, the architectural support at the ISA level and the underlying microarchitecture of these two systems. Our long term goal is to evaluate leading media microprocessors as possible building blocks for future high performance systems.