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The C/?egion Library (CRL) is a new all-software distributed shared memory (DSM) system. CRL requires no special compiler, hardware , or operating system support beyond the ability to send and receive messages. It provides a simple, portable, region-based shared address space programming model that is capab~e of delivering good performance on a wide range(More)
The MIT J-Machine multicomputer has been constructed to study the role of a set of primitive mechanisms in providing efficient support for parallel computing. Each J-Machine node consists of an integrated multicomputer component, the Message-Driven Processor (MDP), and 1 MByte of DRAM. The MDP provides mechanisms to support efficient communication,(More)
Bigtable is a distributed storage system for managing structured data that is designed to scale to a very large size: petabytes of data across thousands of commodity servers. Many projects at Google store data in Bigtable, including web indexing, Google Earth, and Google Finance. These applications place very different demands on Bigtable, both in terms of(More)
T he advent of fast, power-thrifty microprocessors has made possible pocket-size computers with performance approaching that of desktop PCs. This new class of mobile computers enables applications and user-interface modalities not feasible with traditional personal digital assistants and cell phones, while placing new demands on batteries and power(More)
Low-overhead message passing is critical to the performance of many applications. Active Messages reduce the software overhead for message handling: messages are run as handlers instead of as threads, which avoids the overhead of thread management and the unnecessary data copying of other communication models. Scheduling the execution of Active Messages is(More)
<i>Application-specific safe message handlers (ASHs)</i> are designed to provide applications with hardware-level network performance. ASHs are user-written code fragments that safely and efficiently execute in the kernel in response to message arrival. ASHs can direct message transfers (thereby eliminating copies) and send messages (thereby reducing(More)
As the number of processors in distributed-memory multiprocessors grows, eciently supporting a shared-memory programming model becomes dicult. We have designed the Protocol for Hierarchical Directories (PHD) to allow shared-memory support for systems containing massive numbers of processors. PHD eliminates bandwidth problems by using a scalable network,(More)
tion in 1982. We focus on information technology that is relevant to the technical strategy of the Corporation, and that has the potential to open new business opportunities. Research at WRL includes Internet protocol design and implementation, tools to optimize compiled binary code files, hardware and software mechanisms to support scalable shared memory,(More)