Lightweight shared objects in a 64-bit operating system

Today’s high-performance RISC microprocessors have been highly tuned for integer and floating point application performance. These architectures have paid less attention to operating system requirements. At the same time, new operating system designs often have overlooked modern architectural trends which may unavoidably change the relative cost of certain primitive operations. The result is that operating system performance is well below application code performance on contemporary RISCS. This paper examines recent directions in computer architecture and operating systems, and the implications of changes in each domain for the other. The requirements of three components of operating system design are discussed in detail: interprocess communication, virt ual memory, and thread management. For each component, we relate operating system functional and performance needs to the mechanisms available on commercial RISC architectures such as the MIPS R2000 and R3000, Sun SPARC, IBM RS6000, Motorola 88000, and Intel i860. Our analysis reveals a number of specific reasons why the performance of operating system primitives on RISCS has not scaled with integer performance. In addition, we identify areas in which architectures could better (and cost-effectively) accommodate operating system needs, and areas in which operating system design could accommodate certain necessary characteristics of cost-effective highperformance microprocessors. This work was supported in part by the National Science Foundation under Grants No. CCR-8703049, CCR-8619663, and CCR-8907666, by the Washington Technology Center, by the Digital Equipment Corporation Systems Research Center and External Research Program, and by IBM and AT&T Fellowships. Bershad is now with the School of Computer Science, Carnegie Mellon University. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. 01991 ACM 0-89791 -380 -9/91 /0003 -0108 . ..$1 .50

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This paper explores the intersection of operating systems and database systems, focusing on the potential of specialized kernels for cloud-native database systems. Although the idea of custom, DBMS-optimized OS kernels is old, it is largely unrealized due to the demands of hardware compatibility and the reluctance of users to install specialized operating systems. However, the cloud and the database-as-a-service model make custom OS kernels realistic for the first time. Among specialized OS kernel architectures, unikernels stand out for relying on a single address space, eliminating the need for costly process isolation that is provided by general-purpose operating systems. They offer benefits such as the elimination of system call overhead, direct access to hardware, and reduced complexity. Beyond these immediate advantages, unikernels offer a unique opportunity: the possibility to revisit dated POSIX APIs. By allowing direct interaction with modern hardware primitives, unikernels pave the way for the development of novel abstractions that are not confined to the limitations of older APIs, opening doors to a new era of co-designed, high-performance cloud-native data processing systems and OS kernels.

This paper describes Shasta, a system that supports a shared address space in software on clusters of computers with physically distributed memory. A unique aspect of Shasta compared to most other software distributed shared memory systems is that shared data can be kept coherent at a fine granularity. In addition, the system allows the coherence granularity to vary across different shared data structures in a single application. Shasta implements the shared address space by transparently rewriting the application executable to intercept loads and stores. For each shared load or store, the inserted code checks to see if the data is available locally and communicates with other processors if necessary. The system uses numerous techniques to reduce the run-time overhead of these checks. Since Shasta is implemented entirely in software, it also provides tremendous flexibility in supporting different types of cache coherence protocols. We have implemented an efficient cache coherence protocol that incorporates a number of optimizations, including support for multiple communication granularities and use of relaxed memory models. This system is fully functional and runs on a cluster of Alpha workstations.The primary focus of this paper is to describe the techniques used in Shasta to reduce the checking overhead for supporting fine granularity sharing in software. These techniques include careful layout of the shared address space, scheduling the checking code for efficient execution on modern processors, using a simple method that checks loads using only the value loaded, reducing the extra cache misses caused by the checking code, and combining the checks for multiple loads and stores. To characterize the effect of these techniques, we present detailed performance results for the SPLASH-2 applications running on an Alpha processor. Without our optimizations, the checking overheads are excessively high, exceeding 100% for several applications. However, our techniques are effective in reducing these overheads to a range of 5% to 35% for almost all of the applications. We also describe our coherence protocol and present some preliminary results on the parallel performance of several applications running on our workstation cluster. Our experience so far indicates that once the cost of checking memory accesses is reduced using our techniques, the Shasta approach is an attractive software solution for supporting a shared address space with fine-grain access to data.

Current communication architectures suffer from a growing collection of protocols in the host operating systems, gateways and applications, resulting in increasing implementation and maintenance cost, unreliability and difficulties with interoperability. The remote procedure call (RPC) approach has been used in some distributed systems to contain the diversity of application layer protocols within the procedure call abstraction. However, the same technique cannot be applied to lower layer protocols without violating the strict notion of layers.

The broad spectrum of universities, industrial research laboratories, and computer companies represented at the Second IEEE Workshop on Workstation Operating Systems provided a rich snapshot of current activities in operating systems. There were representatives of 19 operating system research projects among the participants and several from commercial offerings. The attendees came from seven countries on three continents: North America, Europe, and South America.Since the last Workshop in 1987, there have been more advances in hardware than in software functions. Software standards continue to emerge in the areas of operating system interfaces, page description languages, window management interfaces, and communication protocols. New software applications exist in the areas of multimedia and multi-node computing. Object-oriented technology is already present in running systems and gaining importance. The areas that the participants perceived needing most future work were operating system abstractions, workstation operation, system responsiveness, input output, network services, management of clusters of workstations, and failure handling.While processor speeds, main memory access speeds, memory density, and secondary storage capacity continue to increase fast, disk seek times have decreased only slightly, and the bandwidth of most local-area networks has not increased at all. FDDI networks are just beginning to be deployed. The software is adjusting to this hardware scenario by using caching at multiple levels of the systems.In the last two years large main memories at individual computing nodes and multi-node computer installations have become common. It is expected that most future computing nodes will have substantial local storage and that high-bandwidth networks will enable the support of continuous media like vocie and video. Input output, to disks, to networks, and to user-oriented devices, is expected to become the central problem in future systems.

STMIK Lombok is an institution engaged in education that process data, about students, student practical data, lecturer data, and correspondence. Media file storage applied STMIK Lombok still on a separate computer, both academic data and practical data, so to access the file must be done on the computer where the storage. Based on the capability of Network Attached Storage in local network, by looking at the need of data storage media on the network at STMIK Lombok and the observation result then designed a network architecture by utilizing Network Attached Storage device with focus on fast storage and data transfer process. Stages of research include Data collection, design, and methods of testing To be able to help solve the problem of separate data access then implemented Network Attached Storage (NAS) which is a network to perform distribution of storage assets owned by the server of a network system that has the advantage of faster access to data stored through Local Area Network, minimal cost and cheap and easy maintenance, from setup to configuration, and available Open Source Software. After doing the testing phase it can be concluded that FreeNas as an operating system used for the processing of network storage media is very capable of handling the task well and the facilities that exist in it is very supportive in storage and accessing files. FreeNas web is very helpful and allows users to configure it other than it can be used without having to spend a large cost, and with the facilities in the FreeNas.

Remote Direct Memory Access (RDMA) is a memory technology that allows remote devices to directly write to and read from each other's memory, bypassing components such as the CPU and operating system. This enables low-latency high-throughput networking, as required for many modern data centres, HPC applications and AI/ML workloads. However, baseline RDMA comprises a highly permissive weak memory model that is difficult to use in practice and has only recently been formalised. In this paper, we introduce the Library of Composable Objects (LOCO), a formally verified library for building multi-node objects on RDMA, filling the gap between shared memory and distributed system programming. LOCO objects are well-encapsulated and take advantage of the strong locality and the weak consistency characteristics of RDMA. They have performance comparable to custom RDMA systems (e.g. distributed maps), but with a far simpler programming model amenable to formal proofs of correctness. To support verification, we develop a novel modular declarative verification framework, called Mowgli, that is flexible enough to model multinode objects and is independent of a memory consistency model. We instantiate Mowgli with the RDMA memory model, and use it to verify correctness of LOCO libraries.

This report documents acceptance test results for the 242-A Evaporator distributive control system upgrade to D/3 version 9.0-2 for year 2000 compliance. This report documents the test results obtained by acceptance testing as directed by procedure HNF-2695. This verification procedure will document the initial testing and evaluation of the potential 242-A Distributed Control System (DCS) operating difficulties across the year 2000 boundary and the calendar adjustments needed for the leap year. Baseline system performance data will be recorded using current, as-is operating system software. Data will also be collected for operating system software that has been modified to correct year 2000 problems. This verification procedure is intended to be generic such that it may be performed on any D/3{trademark} (GSE Process Solutions, Inc.) distributed control system that runs with the VMSTM (Digital Equipment Corporation) operating system. This test may be run on simulation or production systems depending upon facility status. On production systems, DCS outages will occur nine times throughout performance of the test. These outages are expected to last about 10 minutes each.

The forefathers of all current varians of the multiuser multitasking operating system Unix are Kenneth Thompson and Dennis Ritchie. In 1969, in the laboratories of the North American telephone company AT&T, they developed the first Unix prototype, then still written in Assembler, on a PDP-7 system manufactured by Digital Equipment Corporation (DEC). The name “Unix” first derived from a pun MULTICS, which was one og the first interactive operating systems. Based on the idea of creating a system, that would support the cooperation of several programmers in the team communication between them, Thompson and Ritchie conceived the “UNiplexed Information and Computing System” Unics.

TriOS operating system

This report describes the gamma-ray analysis program VAXGAP, which has continually evolved at the Idaho National Engineering Laboratory over a period of several years. It is an integrated suite of computer programs for performing analyses of pulse-height spectra from high-resolution gamma-ray spectrometers and assorted support functions. VAXGAP programs operate on Digital Equipment Corporation (DEC) VAX computers running the VMS operating system, and were written in VAX FORTRAN and DEC Digital Command Language (DCL). These programs make use of DEC GKS and ReGIS for graphical output on standard terminals and printers, and DEC windows for graphics on workstations and terminals that support the X Window System protocol. This report addresses the use of VAXGAP for data acquisition and control, energy scale calibration, and real-time analyses of background and sample pulse-height spectra. Also addressed are the creation and use efficiency tables and isotope libraries, manipulation of spectrum files and their contents, and graphical display of on-going acquisitions, saved spectra, and mathematical fits to spectral peaks.

This report describes the gamma-ray analysis program VAXGAP, which has continually evolved at the Idaho National Engineering Laboratory over a period of several years. It is an integrated suite of computer programs for performing analyses of pulse-height spectra from high-resolution gamma-ray spectrometers and assorted support functions. VAXGAP programs operate on Digital Equipment Corporation (DEC) VAX computers running the VMS operating system, and were written in VAX FORTRAN and DEC Digital Command Language (DCL). These programs make use of DEC GKS and ReGIS for graphical output on standard terminals and printers, and DEC windows for graphics on workstations and terminals that support the X Window System protocol. This report addresses the use of VAXGAP for data acquisition and control, energy scale calibration, and real-time analyses of background and sample pulse-height spectra. Also addressed are the creation and use efficiency tables and isotope libraries, manipulation of spectrum files and their contents, and graphical display of on-going acquisitions, saved spectra, and mathematical fits to spectral peaks.

Efficient buffering for concurrent disk and tape I/O

This paper proposes a virtual memory management system suitable for interactive continuous media applications. Interactive continuous media applications usually require a large amount of memory for storing their code, data, and stack segments. In traditional operating systems, demand paging makes it possible to execute such large applications by storing most pages in secondary disks. However, continuous media applications should avoid page faults for ensuring timing constraints of continuous media since it takes a long time to swap pages between physical memory and secondary storage. Thus, it is difficult to satisfy timing constraints of continuous media. Therefore, some operating systems provide memory wiring primitives that enable applications to wire pages in physical memory by specifying the range of virtual address spaces explicitly. On the other hand, our virtual memory management system enables continuous media applications to reserve physical memory for allocating pages as soon as possible when the applications require the pages. The system implicitly and incrementally allocates and wires pages used for processing timing critical media data. Also, our system supports applications that adapt the amount of wired memory to the memory usage of other continuous media applications.