Carter, J. B., Cox, A. L., Johnson, D. B., and Zwanepoel, W. 1992. Distributed operating systems based on a protected global virtual address space. In 3rd IEEE Workshop on Workstation Operating Systems, Key Biscayne, FL, pp.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....change regional attributes without flushing the entire TLB Ongoing research deals with these questions. It is yet too early for definite answers, but we are not pessimistic. 6 Related Work 64 bit systems: Opal [Chase et al. 1994] Mungi [Heiser et al. 1993] Monads [Rosenberg et al. 1989] and [Carter et al. 1992]. Page table mechanisms: Organick 1972; Cocke 1981; Huck and Hays 1993] TLBs and caches: Koldinger et al. 1992; Kaiser and Czaja 1992; Nagle et al. 1993; Chiueh and Katz 1992] User level mapping: Appel and Li 1991; Hosking and Moss 1993] OO systems: Jul et al. 1988; Krakowiak et al. 1990] ....

Carter, J. B., Cox, A. L., Johnson, D. B., and Zwanepoel, W. 1992. Distributed operating systems based on a protected global virtual address space. In 3rd IEEE Workshop on Workstation Operating Systems, Key Biscayne, FL, pp.

....sizes 4. Can we efficiently change regional attributes without flushing the complete TLB Ongoing research [26, 22, 21, 23] deals with these questions. It is yet too early for definite answers, but we are not pessimistic. 5 Related Work 64 bit systems: Opal [4] Mungi [34, 7] Monads [33] and [2]. Page table mechanisms: 31, 6, 10] TLBs and caches: 16, 15, 30, 5] User level mapping: 1, 9] OO systems: 13, 17] 6 Conclusions Besides that we never can be sure to consider all relevant factors in such an examination, there are remarkable factors of uncertainty: research is required to ....

J. B. Carter, A. L. Cox, D. B. Johnson, and W. Zwanepoel. Distributed operating systems based on a protected global virtual address space. In 3rd IEEE Workshop on Workstation Operating Systems, pages 75--79, Key Biscayne, FL, April 1992.

....6 Comparison In this section we contrast our proposal to other approaches to protection in distributed virtual memory systems. Other GVM like systems have recently been proposed, but these have either ignored protection [14, 15, 16] or have failed to provide sufficient details of its operation [17]. 6.1 MONADS The MONADS project has long recognised the value of a global address space for the support of persistence. The system was designed to provide strong support for software engineering principles, such as modularisation and encapsulation. The MONADS protection model is a reflection of ....

J. B. Carter, A. L. Cox, D. B. Johnson, and W. Zwaenepoel. Distributed operating systems based on a protected global virtual address space. In WWOS-III [22], pages 75--9.

....space will be revolutionary instead of evolutionary with respect to the way operating systems and applications can use virtual memory. Koldinger, Chase, Eggers [8] Experimental single address space operating systems are for example Opal [4, 3] and Mungi [6] a similar design is described in [2] and [16] The latter system especially relies on rich per page protection facilities. One serious problem coming up in this context is sparsity. A 2 64 byte address space will ever be sparsely occupied. Otherwise, a 2 32 space would do as well. After all that we have learned from history ....

J. B. Carter, A. L. Cox, D. B. Johnson, and W. Zwanepoel. Distributed operating systems based on a protected global virtual address space. In 3rd IEEE Workshop on Workstation Operating Systems, pages 75--79, Key Biscayne, FL, April 1992.

....large for a malicious or buggy program to search for an object whose location has not been obtained by proper means. Carter et al. have proposed building a distributed shared memory (DSM) system using a large address space to give a process direct access to memory objects spread across many nodes [5]. Although most current systems cannot support enough real memory to exhaust a 32 bit address space, the aggregate memory of a large number of such systems could easily exceed the range of a 32 bit address, especially if segmented for convenience in allocation and management. 3. Technical ....

John B. Carter, Alan L. Cox, David B. Johnson, and Willy Zwaenepoel. Distributed Operating Systems Based on a Protected Global Virtual Address Space. In Proceedings of the Third Workshop on Workstation Operating Systems, pages 75-79. IEEE Computer Society, Key Biscayne, FL, April, 1992.

....6 Comparison In this section we contrast our proposal to other approaches to protection in distributed virtual memory systems. Other GVM like systems have recently been proposed, but these have either ignored protection [14, 15, 16] or have failed to provide sufficient details of its operation [17]. 6.1 MONADS The MONADS project has long recognised the value of a global address space for the support of persistence. The system was designed to provide strong support for software engineering principles, such as modularisation and encapsulation. The MONADS protection model is a reflection of ....

J. B. Carter, A. L. Cox, D. B. Johnson, and W. Zwaenepoel. Distributed operating systems based on a protected global virtual address space. In Workshop on Workstation Operating Systems [21], pages 75--9.

....space on the 24 bit virtual addresses that were available to them. However, the advent of 64 bit virtual addressing will enable systems to use a true single virtual address space. The issues related to how operating systems can use a very large address space are currently being investigated (Carter et al. 1992; Koldinger et al. 1992; Lazowska, 1992; Okamoto et al. 1992) However, there is a drawback: whereas the resource management code within the operating system does not have to be rewritten for each application, a severely minimal kernel supporting only basic hardware dependent operations with ....

....the IBM 38 supported a flat, single level 64 bit virtual address space 41 . Other operating system work is starting to focus on the large address space model associated with the advent of 64 bit addressing. In such systems the standard process equals address space association can break down (Carter et al. 1992). Process virtual address spaces will be regions in the single address space, and protection mechanisms based on the protection domain model will be required (Lazowska, 1992) However, virtual address translations will be the same in all protection domains, facilitating sharing. The three systems ....

[Article contains additional citation context not shown here]

Carter, J.B., D.B. Johnson, A.L. Cox and W. Zwaenepoel (1992) Distributed operating systems based on a protected global virtual address space. Rice COMP TR92-186.

....physical memory approaches 64 bits. It is worth noting, however, than in the past bus size has increased faster than physical memory size. Also, ARPC precludes other uses for the 64 bit address space which may be superior. Large databases [Stonebraker Dozier 1991] or distributed systems [Carter et al. 1992] can use most of a 64 bit space. 6 Performance Results We implemented a test prototype of anonymity on an Intel 486 33 machine, capable of about 15 SPECint. The base operating system was Linux 0.98.4, a copylefted POSIX clone for the 386 architecture [Torvalds 1992] The 486 is a 32 bit machine, ....

....own protection domain; the goal is uniformity of naming. Using identical addresses to reference the same objects in all domains allows increased flexibility in sharing complex data structures. A context switch, however, still involves switching page tables. Other systems also follow this pattern [Carter et al. 1992]. 8 Conclusion Anonymous RPC exploits a simple property of memory systems: that it is impossible to address data whose address is unknown. With the advent of 64 bit machines, it is now possible to take advantage of this property, by placing segments at random locations in a very large, sparse ....

Carter, J. B., Cox, A. L., Johnson, D. B., and Zwaenepoel, W. Distributed Operating Systems Based on a Protected Global Address Space. In Proceedings of the Third Workshop on Workstation Operating Systems, April 1992.

....support for protection, there is little or nothing on such important issues as address space management, memory coherence, fault tolerance, or even the software model of protection. It is not clear how far these issues have been researched at all. Another SAOS has been proposed by Carter et al. [9]. That project is also still in a conceptual stage and too little detail has been published to contrast their approach from ours. However, these projects show that the recent progress in computer architecture is leading to a new approach in operating systems design. The remainder of this paper ....

J. B. Carter, A. L. Cox, D. B. Johnson, and W. Zwaenepoel. Distributed operating systems based on a protected global virtual address space. In Workshop on Workstation Operating Systems [25], pages 75--9.

....is, their interpretation depends on the process using the address. Next generation operating systems can utilize the 1 Unix is a trademark of Unix Systems Laboratories, Inc. wider virtual addresses of emerging 64 bit architectures by exploiting the concept of a single virtual address space [Carter et al. 92, Chase et al. 92a, Chase et al. 92b, Okamoto et al. 92, Scott et al. 90] In such a system, addresses are unique and context independent: an address has the same meaning and translation, independent of the process that issues it. Hardware based memory protection still exists within this single ....

J. Carter, A. Cox, D. Johnson, and W. Zwaenepoel. Distributed operating systems based on a protected global virtual address space. Technical Report Rice COMP TR92--186, Rice Univ., Department of Computer Science, Apr. 1992. Also appeared in the 3rd IEEE Workshop on Workstation Operating Systems, Apr. 1992.

....a uniform address space, but it seems possible that up to a few hundred machines can be included. Sharing an address space involves a certain level of trust and agreement and it seems therefore reasonable only to distribute it among machines within an organizational unit. Current proposals [2, 5, 6, 20] therefore focus on machines within a single local area network. Although most of these proposals restrict their view to a network of homogeneous machines, it might be possible to allow different architectures to be included in the address space. To support the uniform naming, only 64 bit machines ....

....shown with Munin [4] Traditional distributed shared memory systems only support data shipping and RPC systems only support function shipping. We think that the system should support both. The type of invocation can be specified by the server and be used by the client by using different stubs [5]. 4.5 Locating Objects When a page or segment migrates around the network, from data shipping or load balancing, the question arises of how to keep track of its location. A solution based on a central manager that knows the location of all pages in the system is undesirable because it is a ....

John B. Carter, Alan L. Cox, David B. Johnson, and Willy Zwaenepoel. Distributed operating system based on a protected global virtual address space. In Proc. of the Third Workshopon Workstation Operating Systems, April 1992.

....in a single address space, while protecting the servers from client accesses. We view support for these in server clients and in kernel servers as the first step in an evolution towards a single address space system that can efficiently support existing programs written for existing systems [4]. Finally, we have experimented with the option of linking specially authorized routines into the kernel on a per client basis. FLEX lets kernel level services and associated trap vectors be added, allowing users to access privileged data and devices in a controlled fashion, not envisioned by the ....

....user process has been loaded into the database server s address space. Thus, communications between the user process and database server occur via protected procedure calls (involving traps) or directly through normal procedure calls and shared memory, depending on the desired level of protection [4]. Additionally, because this user process needs real time performance guarantees, it uses its own paging mechanism (implemented as an in kernel server) to control its paging behavior. This mechanism uses normal kernel level services to access disk and the VM hardware, but otherwise it is ....

[Article contains additional citation context not shown here]

J.B. Carter, A. Cox, D. Johnson, and W. Zwaenepoel. Distributed operating systems based on a protected global virtual address space. In Third Workshop on Workstation Operating Systems, May 1992.

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