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Fbufs: A High-Bandwidth Cross-Domain Transfer Facility
- in Proceedings of the Fourteenth ACM symposium on Operating Systems Principles
, 1993
"... We have designed and implemented a new operating system facility for I/O buffer management and data transfer across protection domain boundaries on shared memory machines. This facility, called fast buffers (fbufs), combines virtual page remapping with shared virtual memory, and exploits locality in ..."
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Cited by 332 (15 self)
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We have designed and implemented a new operating system facility for I/O buffer management and data transfer across protection domain boundaries on shared memory machines. This facility, called fast buffers (fbufs), combines virtual page remapping with shared virtual memory, and exploits locality in I/O traffic to achieve high throughput withoutcompromising protection, security, or modularity. Its goal is to help deliver the high bandwidth afforded by emerging high-speed networks to user-level processes, both in monolithic and microkernel-based operating systems. This paper outlines the requirements for a cross-domain transfer facility, describes the design of the fbuf mechanism that meets these requirements, and experimentally quantifies the impact of fbufs on network performance. 1 Introduction Optimizing operations that cross protection domain boundaries has received a great deal of attention recently [2, 3]. This is because an efficient cross-domain invocation facility enables a ...
A Hierarchical CPU Scheduler for Multimedia Operating Systems
, 1996
"... The need for supportingvariety of hard and soft real-time, as well as best effort applications in a multimedia computing environment requires an operating system framework that: (1) enables different schedulers to be employed for different application classes, and (2) provides protection between the ..."
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Cited by 324 (6 self)
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The need for supportingvariety of hard and soft real-time, as well as best effort applications in a multimedia computing environment requires an operating system framework that: (1) enables different schedulers to be employed for different application classes, and (2) provides protection between the various classes of applications. We argue that these objectives can be achieved by hierarchical partitioning of CPU bandwidth, in which an operating system partitions the CPU bandwidth among various application classes, and each application class, in turn, partitions its allocation (potentially using a different scheduling algorithm) among its sub-classes or applications. We present Start-time Fair Queuing (SFQ) algorithm, which enables such hierarchical partitioning. We have implemented a hierarchical scheduler in Solaris 2.4. We describe our implementation, and demonstrate its suitability for multimedia operating systems. 1
Building Secure and Reliable Network Applications
, 1996
"... ly, the remote procedure call problem, which an RPC protocol undertakes to solve, consists of emulating LPC using message passing. LPC has a number of "properties" -- a single procedure invocation results in exactly one execution of the procedure body, the result returned is reliably deliv ..."
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Cited by 230 (16 self)
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ly, the remote procedure call problem, which an RPC protocol undertakes to solve, consists of emulating LPC using message passing. LPC has a number of "properties" -- a single procedure invocation results in exactly one execution of the procedure body, the result returned is reliably delivered to the invoker, and exceptions are raised if (and only if) an error occurs. Given a completely reliable communication environment, which never loses, duplicates, or reorders messages, and given client and server processes that never fail, RPC would be trivial to solve. The sender would merely package the invocation into one or more messages, and transmit these to the server. The server would unpack the data into local variables, perform the desired operation, and send back the result (or an indication of any exception that occurred) in a reply message. The challenge, then, is created by failures. Were it not for the possibility of process and machine crashes, an RPC protocol capable of overcomi...
A survey of qos architectures
- Multimedia Systems
, 1996
"... Over the past several years there has been a considerable amount of research within the field of quality of service (QoS) support for distributed multimedia systems. To date, most of the work has been within the context of individual architectural layers such as the distributed system platform, oper ..."
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Cited by 224 (2 self)
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Over the past several years there has been a considerable amount of research within the field of quality of service (QoS) support for distributed multimedia systems. To date, most of the work has been within the context of individual architectural layers such as the distributed system platform, operating system, transport subsystem and network. Much less progress has been made in addressing the issue of overall end-to-end support for multimedia communications. In recognition of this, a number of research teams have proposed the development of QoS architectures which incorporate quality of service configurable interfaces and quality of service driven control and management mechanisms across all architectural layers. This paper examines the state-of-the-art in the development of QoS architectures. The approach taken is to present QoS terminology and a generalised QoS framework for understanding and discussing quality of service in the context of distributed multimedia systems. Following this, we evaluate a number of QoS architectures that have emerged in the literature. 1.
A Feedback-driven Proportion Allocator for Real-Rate Scheduling
, 1999
"... In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatic ..."
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Cited by 222 (27 self)
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In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatically both proportion and period. Applications with known requirements, such as isochronous software devices, can bypass the adaptive scheduler by specifying their desired proportion and/or period. As a result, our scheme provides reservations to applications that need them, and the benefits of proportion and period to those that do not. Adaptive scheduling using proportion and period has several distinct benefits over either fixed or adaptive priority based schemes: finer grain control of allocation, lower variance in the amount of cycles allocated to a thread, and avoidance of accidental priority inversion and starvation, including defense against denial-of-service attacks. This paper descr...
A Quality of Service Architecture
, 1996
"... ..................................................................... ....... i Acknowledgements ............................................................... ii 1. Introduction .................................................................... 1 2. Quality of Service Terminology, Principles and ..."
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Cited by 220 (23 self)
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..................................................................... ....... i Acknowledgements ............................................................... ii 1. Introduction .................................................................... 1 2. Quality of Service Terminology, Principles and Concepts ................. 17 2.1 Terminology.......................................................... .......................17 2.2 Qos Principles........................................................... ...................18 2.2.1 Integration Principle .................................................................19 2.2.2 Separation Principle .................................................................19 2.2.3 Transparency Principle............................................................ ..19 2.2.4 Asynchronous Resource Management Principle .................................20 2.2.5 Performance Principle............................................................ ...20 2.3 QoS S...
Metascheduling for continuous media
- ACM Transactions on Computer Systems
, 1993
"... Next-generation distributed systems will support corLtLzLzLous medLa (digztal audio and video) in the same framework as other data. Many applications that use continuous media need guaran-teed end-to-end performance (bounds on throughput and delay). To reliably support these requirements, system com ..."
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Cited by 160 (3 self)
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Next-generation distributed systems will support corLtLzLzLous medLa (digztal audio and video) in the same framework as other data. Many applications that use continuous media need guaran-teed end-to-end performance (bounds on throughput and delay). To reliably support these requirements, system components such as CPU schedulers, networks, and file systems must offer performance guarantees. A rnetasclzedtder coordinates these components, negotiating end-to-end guarantees on behalf of clients. The CM-resource model, described in this paper, provides a basis for such a metascheduler. It defines a workload parameterizatlon, an abstract interface to resources, and an algorithm for reserving multiple resources. The model uses an economic approach to dividing end-to-end delay, and it allows system components to “work ahead,” improving the performance of nonreal-time workload.
A File System for Continuous Media
, 1992
"... INTRODUCTION Current disk drives have raw data rates of 5 to 10 million bits per second (Mbps) or more. Such rates suffice for many forms of digital audio and motion video (continuous media, or CM) data: audio data rates are from 8 Kbps to 1.4 Mbps, while compressed video ranges from one to several ..."
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Cited by 152 (0 self)
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INTRODUCTION Current disk drives have raw data rates of 5 to 10 million bits per second (Mbps) or more. Such rates suffice for many forms of digital audio and motion video (continuous media, or CM) data: audio data rates are from 8 Kbps to 1.4 Mbps, while compressed video ranges from one to several Mbps. However, when a disk is accessed via a general-purpose file system, the data rates seen by clients are generally lower and may vary unpredictably. We have developed a Continuous Media File System (CMFS) whose clients read and write files in "sessions", each with a guaranteed minimum data rate. Multiple sessions, perhaps with different data rates, can coexist. CMFS can handle non-real-time traffic concurrently with these real-time sessions. #################################### Authors' addresses: D.P. Anderson, 1891 East Francisco Blvd. San Rafael, CA 94901. Y. Osawa, MO Business Development Division, Storage Systems Group, Sony
Processor Capacity Reserves for Multimedia Operating Systems
- IN PROCEEDINGS OF THE IEEE INTERNATIONAL CONFERENCE ON MULTIMEDIA COMPUTING AND SYSTEMS
, 1994
"... Multimedia applications have timing requirements that cannot generally be satisfied using time-sharing scheduling algorithms and system structures. To effectively support these types of programs, operating systems must support processor capacity reservation. A capacity reservation and enforcement me ..."
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Cited by 118 (7 self)
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Multimedia applications have timing requirements that cannot generally be satisfied using time-sharing scheduling algorithms and system structures. To effectively support these types of programs, operating systems must support processor capacity reservation. A capacity reservation and enforcement mechanism isolates programs from the timing and execution characteristics of other programs in the same way that a memory protection system isolates programs from memory access by other programs. In this paper, we characterize the timing requirements and processor capacity reservation requirements for multimedia applications, we describe a scheduling framework to support reservation and admission control, and we introduce a novel reserve abstraction, specifically designed for the microkernel architecture, for controlling processor usage.
Self-paging in the nemesis operating system
- In Proceedings of the 3rd USENIX Symposium on Operating Systems Design and Implementation
, 1999
"... In contemporary operating systems, continuous media (CM) applications are sensitive to the behaviour of other tasks in the system. This is due to contention in the kernel (or in servers) between these applications. To properly support CM tasks, we require “Quality of Service Firewalling” between dif ..."
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Cited by 95 (3 self)
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In contemporary operating systems, continuous media (CM) applications are sensitive to the behaviour of other tasks in the system. This is due to contention in the kernel (or in servers) between these applications. To properly support CM tasks, we require “Quality of Service Firewalling” between different applications. This paper presents a memory management system supporting Quality of Service (QoS) within the Nemesis operating system. It combines application-level paging techniques with isolation, exposure and responsibility in a manner we call self-paging. This enables rich virtual memory usage alongside (or even within) continuous media applications. 1
