Mth: Codesigned Hardware/Software Support for Fine Grain Threads

Abstract

Multi-core processors are ubiquitous in all market segments from embedded to high performance computing, but only few applications can efficiently utilize them. Existing parallel frameworks aim to support thread-level parallelism in applications, but the imposed overhead prevents their usage for small problem instances. This work presents Micro-threads (Mth) a hardware-software proposal focused on a shared thread management model enabling the use of parallel resources in applications that have small chunks of parallel code or small problem inputs by a combination of software and hardware: Delegation of the resource control to the application, an improved mechanism to store and fill processor's context, and an efficient synchronization system. Four sample applications are used to test our proposal: HSL filter (trivially parallel), FFT Radix2 (recursive algorithm), LU decomposition (barrier every cycle) and Dantzig algorithm (graph based, matrix manipulation). The results encourage the use of Mth and could smooth the use of multiple cores for applications that currently can not take advantage of the proliferation of the available parallel resources in each chip.