Biblio

The HPC application community has proposed many new application communication structures, middleware interfaces, and communication models to improve HPC application performance. Modifying proxy applications is the standard practice for the evaluation of these novel methodologies. Currently, this requires the creation of a new version of the proxy application for each combination of the approach being tested. In this article, we present a modular proxy-application framework, MiniMod, that enables evaluation of a combination of independently written computation kernels, data transfer logic, communication access, and threading libraries. MiniMod is designed to allow rapid development of individual modules which can be combined at runtime. Through MiniMod, developers only need a single implementation to evaluate application impact under a variety of scenarios.We demonstrate the flexibility of MiniMod’s design by using it to implement versions of a heat diffusion kernel and the miniFE finite element proxy application, along with a variety of communication, granularity, and threading modules. We examine how changing communication libraries, communication granularities, and threading approaches impact these applications on an HPC system. These experiments demonstrate that MiniMod can rapidly improve the ability to assess new middleware techniques for scientific computing applications and next-generation hardware platforms.

Security is a universal concern across a multitude of sectors involved in the transfer and storage of computerized data. In the realm of cryptography, random number generators (RNGs) are integral to the creation of encryption keys that protect private data, and the production of uniform probability outcomes is a revenue source for certain enterprises (most notably the casino industry). Arbitrary thread schedule reconstruction of compare-and-swap operations is used to generate input traces for the Blum-Elias algorithm as a method for constructing random sequences, provided the compare-and-swap operations avoid cache locality. Threads accessing shared memory at the memory controller is a true random source which can be polled indirectly through our algorithm with unlimited parallelism. A theoretical and experimental analysis of the observation and reconstruction algorithm are considered. The quality of the random number generator is experimentally analyzed using two standard test suites, DieHarder and ENT, on three data sets.