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128
System architecture directions for networked sensors
- IN ARCHITECTURAL SUPPORT FOR PROGRAMMING LANGUAGES AND OPERATING SYSTEMS
, 2000
"... Technological progress in integrated, low-power, CMOS communication devices and sensors makes a rich design space of networked sensors viable. They can be deeply embedded in the physical world or spread throughout our environment. The missing elements are an overall system architecture and a methodo ..."
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Cited by 1777 (59 self)
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Technological progress in integrated, low-power, CMOS communication devices and sensors makes a rich design space of networked sensors viable. They can be deeply embedded in the physical world or spread throughout our environment. The missing elements are an overall system architecture and a methodology for systematic advance. To this end, we identify key requirements, develop a small device that is representative of the class, design a tiny event-driven operating system, and show that it provides support for efficient modularity and concurrency-intensive operation. Our operating system fits in 178 bytes of memory, propagates events in the time it takes to copy 1.25 bytes of memory, context switches in the time it takes to copy 6 bytes of memory and supports two level scheduling. The analysis lays a groundwork for future architectural advances.
Towards an Active Network Architecture
- Computer Communication Review
, 1996
"... Active networks allow their users to inject customized programs into the nodes of the network. An extreme case, in which we are most interested, replaces packets with "capsules" -- program fragments that are executed at each network router/switch they traverse. Active architectures permit ..."
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Cited by 492 (7 self)
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Active networks allow their users to inject customized programs into the nodes of the network. An extreme case, in which we are most interested, replaces packets with "capsules" -- program fragments that are executed at each network router/switch they traverse. Active architectures permit a massive increase in the sophistication of the computation that is performed within the network. They will enable new applications, especially those based on application-specific multicast, information fusion, and other services that leverage network-based computation and storage. Furthermore, they will accelerate the pace of innovation by decoupling network services from the underlying hardware and allowing new services to be loaded into the infrastructure on demand. In this paper, we describe our vision of an active network architecture, outline our approach to its design, and survey the technologies that can be brought to bear on its implementation. We propose that the research community mount a j...
Dealing with disaster: Surviving misbehaved kernel extensions
- In OSDI
, 1996
"... Today’s extensible operating systems allow applications to modify kernel behavior by providing mechanisms for application code to run in the kernel address space. The advantage of this approach is that it provides improved application flexibility and performance; the disadvantage is that buggy or ma ..."
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Cited by 279 (9 self)
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Today’s extensible operating systems allow applications to modify kernel behavior by providing mechanisms for application code to run in the kernel address space. The advantage of this approach is that it provides improved application flexibility and performance; the disadvantage is that buggy or malicious code can jeopardize the integrity of the kernel. It has been demonstrated that it is feasible to use safe languages, software fault isolation, or virtual memory protection to safeguard the main kernel. However, such protection mechanisms do not address the full range of problems, such as resource hoarding, that can arise when application code is introduced into the kernel. In this paper, we present an analysis of extension mechanisms in the VINO kernel. VINO uses software fault isolation as its safety mechanism and a lightweight transaction system to cope with resource-hoarding. We explain how these two mechanisms are sufficient to protect against a large class of errant or malicious extensions, and we quantify the overhead that this protection introduces. We find that while the overhead of these techniques is high relative to the cost of the extensions themselves, it is low relative to the benefits that extensibility brings.
Making Paths Explicit in the Scout Operating System
, 1996
"... This paper makes a case for paths as an explicit abstraction in operating system design. Paths provide a unifying infrastructure for several OS mechanisms that have been introduced in the last several years, including fbufs, integrated layer processing, packet classifiers, code specialization, and m ..."
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Cited by 231 (24 self)
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This paper makes a case for paths as an explicit abstraction in operating system design. Paths provide a unifying infrastructure for several OS mechanisms that have been introduced in the last several years, including fbufs, integrated layer processing, packet classifiers, code specialization, and migrating threads. This paper articulates the potential advantages of a path-based OS structure, describes the specific path architecture implemented in the Scout OS, and demonstrates the advantages in a particular application domain---receiving, decoding, and displaying MPEG-compressed video. 1 Introduction Layering is a fundamental structuring technique with a long history in system design. From early work on layered operating systems and network architectures [12, 32], to more recent advances in stackable systems [27, 15, 14, 26], layering has played a central role in managing complexity, isolating failure, and enhancing configurability. This paper describes a complementary, but equally f...
Cache-Conscious Data Placement
- in Proceedings of the Eighth International Conference on Architectural Support for Programming Languages and Operating Systems
, 1998
"... As the gap between memory and processor speeds continues to widen, cache efficiency is an increasingly important component of processor performance. Compiler techniques have been used to improve instruction cache performance by mapping code with temporal locality to different cache blocks in the vir ..."
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Cited by 163 (4 self)
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As the gap between memory and processor speeds continues to widen, cache efficiency is an increasingly important component of processor performance. Compiler techniques have been used to improve instruction cache performance by mapping code with temporal locality to different cache blocks in the virtual address space eliminating cache conflicts. These code placement techniques can be applied directly to the problem of placing data for improved data cache performance. In this paper we present a general framework for Cache Conscious Data Placement. This is a compiler directed approach that creates an address placement for the stack (local variables), global variables, heap objects, and constants in order to reduce data cache misses. The placement of data objects is guided by a temporal relationship graph between objects generated via profiling. Our results show that profile driven data placement significantly reduces the data miss rate by 24% on average. 1 Introduction Much effort has b...
Fine-grained dynamic instrumentation of commodity operating system kernels
, 1999
"... We have developed a technology, fine-grained dynamic instrumentation of commodity kernels, which can splice (insert) dynamically generated code before almost any machine code instruction of a completely unmodified running commodity operating system kernel. This technology is well-suited to performan ..."
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Cited by 130 (5 self)
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We have developed a technology, fine-grained dynamic instrumentation of commodity kernels, which can splice (insert) dynamically generated code before almost any machine code instruction of a completely unmodified running commodity operating system kernel. This technology is well-suited to performance profiling, debugging, code coverage, security auditing, runtime code optimizations, and kernel extensions. We have designed and implemented a tool called KernInst that performs dynamic instrumentation on a stock production Solaris kernel running on an UltraSPARC. On top of KernInst, we have implemented a kernel performance profiling tool, and used it to understand kernel and application performance under a Web proxy server workload. We used this information to make two changes (one to the kernel, one to the proxy) that cumulatively reduce the percentage of elapsed time that the proxy spends opening disk cache files from 40 % to 7%. 1
PATHFINDER: A Pattern-Based Packet Classifier
- In Proceedings of the First Symposium on Operating Systems Design and Implementation
, 1994
"... This paper describes a pattern-based approach to building packet classifiers. One novelty of the approach is that it can be implemented efficiently in both software and hardware. A performance study shows that the software implementation is about twice as fast as existing mechanisms, and that the ha ..."
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Cited by 122 (6 self)
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This paper describes a pattern-based approach to building packet classifiers. One novelty of the approach is that it can be implemented efficiently in both software and hardware. A performance study shows that the software implementation is about twice as fast as existing mechanisms, and that the hardware implementation is currently able to keep up with OC-12 (622Mbps) network links and is likely to operate at gigabit speeds in the near future. 1 Introduction A packet classifier is a mechanism that inspects incoming network packets, and based on the values found in select header fields, determines how each is to be processed. A classifier can be thought of as assigning a tag (type) to each packet, or alternatively, identifying the flow or path to which the packet belongs. We call this mechanism a packet classifier rather than a packet filter because it more accurately describes the function being performed---it classifies all packets, rather than filtering out select packets. Packet ...
Using AspectC to improve the modularity of path-specific customization in operating system code
, 2001
"... Layered architecture in operating system code is often compromised by execution path-specific customizations such as prefetching, page replacement and scheduling strategies. Pathspecific customizations are difficult to modularize in a layered architecture because they involve dynamic context passing ..."
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Cited by 121 (8 self)
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Layered architecture in operating system code is often compromised by execution path-specific customizations such as prefetching, page replacement and scheduling strategies. Pathspecific customizations are difficult to modularize in a layered architecture because they involve dynamic context passing and layer violations. Effectively they are vertically integrated slices through the layers. An initial experiment using an aspect-oriented programming language to refactor prefetching in the FreeBSD operating system kernel shows significant benefits, including easy (un)pluggability of prefetching modes, independent development of prefetching modes, and overall improved comprehensibility. Keywords aspect-oriented programming, software modularity, operating system design 1.
