Deborah A. Wallach

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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)
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 of(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)
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)
Predicting the time of full discharge of a finite-capacity energy source, such as a battery, is important for the design of portable electronic systems and applications. In this paper we present a novel analytical model of a battery that not only can be used to predict battery lifetime, but also can serve as a cost function for optimization of the energy(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)
<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)
The computing requirements of battery-powered systems are increasing faster than battery capacity. Because large, heavy batteries are unacceptable for handheld computers, low-power design and power management are crucial for these systems. One of the main obstacles limiting these techniques is the lack of a detailed analysis of system power under(More)