CSR---EHS. Quest: A System for Application-Specific Real-Time Services

为了消除专有系统和专用硬件的成本，许多实时和嵌入式计算平台都建立在商品操作系统和通用硬件之上。不幸的是，许多这样的系统不适合实时应用程序的低延迟和可预测的时间要求。因此，本建议将重点放在针对低成本商品计算平台的特定应用服务技术上，以满足实时服务保障。这项工作的重点之一是系统软件的结构，以便在一系列常用（但有差异的）硬件上为许多不同的应用程序重用公共代码库。考虑了提供服务隔离、保护以及高效和可预测执行的新方法。本研究扩展了之前在系统可扩展性和安全性方面所做的努力。该研究寻求在诸如Linux之类的商品系统内核以及用户级的服务质量安全（QoS安全）扩展。通过QoS安全，我们的意思是服务不仅是内存安全的，因为它不会侵犯未授予访问权限的地址，而且它根据服务质量（QoS）约束以可预测的方式执行。从先前在用户级沙箱（ULS）和安全内核扩展（SafeX）方面的工作中吸取的经验教训被用于设计一种名为Quest的新系统软件架构，该架构由机制和策略组成，可确保实时和嵌入式应用程序的用户指定服务的安全和可预测组合。

In order to eliminate the costs of proprietary systems and special purpose hardware, many real-time and embedded computing platforms are being built on commodity operating systems and generic hardware. Unfortunately, many such systems are ill-suited to the low-latency and predictable timing requirements of real-time applications. This proposal, therefore, focuses on application-specific service technologies for low-cost commodity computing platforms, so that real-time service guarantees can be met. One of the main thrusts of this work is the structure of systems software, so that a common code-base can be reused for a number of diverse applications on a range of commonly-used (but contrasting) hardware. Novel methods for providing service isolation, protection, and efficient and predictable execution are considered.This research expands on prior efforts towards system extensibility and safety. The research seeks quality-of-service safe (QoS safe) extensions within the kernels of commodity systems such as Linux, as well as at user-level. By QoS safe we mean a service is not only memory-safe, in that it does not encroach on addresses for which it is not granted access, but also that it executes in a predictable manner according to quality of service (QoS) constraints. Lessons from prior work on user-level sandboxing (ULS) and safe kernel extensions (SafeX) are being used to design a new system software architecture, called Quest, comprising mechanisms and policies that guarantee the safe and predictable composition of user-specified services for real-time and embedded applications.