Adaptive Structure Aware Memory Systems

Abstract

Abstract : This report describes the design of the Impulse architecture and shows how an Impulse memory system can be used in a variety of ways to improve the performance of data-intensive applications. The Impulse design does not require any modification to processor, cache, or bus designs - all novel hardware functionality resides at the memory controller. As a result, Impulse optimizations can be adopted in conventional systems without major system changes. Impulse can be used to: (1) dynamically create superpages cheaply, (2) dynamically recolor physical pages, to perform strided fetches, (3) perform gathers and scatters through indirection vectors, and (4) dynamically gather cache lines from randomly dispersed data. Impulse improved the performance of six DARPA Data Intensive System (DIS) program Stressmarks from 1 .25X to 16X (or 470X in the case of in-place CornerTurn, which was unusually well-suited for Impulse). Impulse sped up the twenty-two programs in the benchmark suite by a geometric mean of 2.4X on 2002-class hardware, and 3.3X on 2007-class hardware. In addition to its applicability for data-intensive applications, Impulse can also be used by the OS for dynamic superpage creation, which is useful for arbitrary applications.