Bare-Metal Execution of Hard Real-Time Tasks Within a General-Purpose Operating System

Integrating high performance and real-time demands on multi-processor systems is a challenging task. We present our concept of isolating processes from a general-purpose operating system without deeply invading modifications. This allows executing code on dedicated CPUs with minimum latency and jitter like bare-metal on micro-controllers. The unbounded execution of mixed critical processes on the same system induces performance interference in real-time tasks. We present the implementation of isolated partitions on multi-processor x86 systems running Linux and describe challenges restoring operating system stability. This work also presents our experience with Non-Uniform Memory Access architectures that allow to partition the system in a way that the impact to memory and I/O transfers of other partitions is minimized

Evaluation of Optimized Barrier Algorithms for SCI Networks with Different MPI Implementations

The SCI Collectives Library is a new software package which implements optimized collective communication operations on SCI networks. It is designed to be coupled to different higher-level communication libraries (especially MPI implementations) by adapter modules, thereby giving them access to these optimized collectives. In this work, we present the design of the SCI Collectives Library and of adapter modules for Open MPI and NMPI. We also describe various barrier algorithms which we have implemented for this library and compare their performance to one another and to the barrier performance of MPI implementations which include support for SCI. 1