CPU Resource Reservation for Simultaneous Multi-Thread Systems

Simultaneous Multi-Thread (SMT) techniques are becoming popular because they increase the efficiency of CPU resource usage by allowing multiple threads to run on a single physical processor at a very fine granularity. Emerging real-time applications, however, may not benefit from the SMT techniques because those techniques often compromise the predictable performance characteristics of applications, which real-time applications typically need to meet their computation deadlines. In this paper, we propose a new resource reservation scheme for SMT systems. In this scheme, a task scheduler dynamically enables and disables the SMT facility while real-time applications are running by monitoring the progress of the real-time applications. In this way, real-time applications can still meet their computation deadlines, and other best-effort applications can gain a high throughput due to the SMT facility. We have implemented this scheme on a Linux kernel and evaluated it on a Hyper-Threading processor, an Intel's implementation of SMT techniques. Our experimental results have shown that, for our workload, our scheme can guarantee real-time applications to use reserved resources while best-effort applications can obtain a high throughput due to the SMT facility.

By: Hiroshi Inoue, Takao Moriyama, Yasushi Negishi, and Moriyoshi Ohara

Published in: RT0676 in 2007


This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.


Questions about this service can be mailed to reports@us.ibm.com .