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Abstract-Dynamically allocated and manipulated data structures cannot be translated into hardware unless there is an upper bound on the amount of memory the program uses during all executions. This bound can depend on the generic parameters to the program, i.e., program inputs that are instantiated at synthesis time. We propose a constraint based method for the discovery of memory usage bounds, which leads to the firstknown C-to-gates hardware synthesis supporting programs with non-trivial use of dynamically allocated memory, e.g., linked lists maintained with malloc and free. We illustrate the practicality of our tool on a range of examples.

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Abstract-In terms of performance, solid state devices promise to be superior technology to mechanical disks. This study investigates performance of several up-to-date high-end consumer and enterprise Flash solid state devices (SSDs) and relates their performance to that of mechanical disks. For the purpose of this evaluation, the IOZone benchmark is run in single-threaded mode with varying request size and access pattern on an ext3 filesystem mounted on these devices. The price of the measured devices is then used to allow for comparison of price per performance. Measurements presented in this study offer an evaluation of cost-effectiveness of a Flash based SSD storage solution over a range of workloads.In particular, for sequential access pattern the SSDs are up to 10 times faster for reads and up to 5 times faster than the disks. For random reads, the SSDs provide up to 200x performance advantage. For random writes the SSDs provide up to 135x performance advantage. After weighting these numbers against the prices of the tested devices, we can conclude that SSDs are approaching price per performance of magnetic disks for sequential access patterns workloads and are superior technology to magnetic disks for random access patterns.

This report describes how a file system level log-based technique can improve the write performance of many-to-one write checkpoint workload typical for high performance computations. It is shown that a simple log-based organization can provide for substantial improvements in the write performance while retaining the convenience of a single flat file abstraction. The improvement of the write performance comes at the cost of degraded read performance however. Techniques to alleviate the read performance penalty, such as file reconstruction on the first read, are discussed.