Engler, D., Kaashoek, M.F., and O'Toole, J. Exokernel, an operating system architecture for application-level resource management. In Proceedings of the 15th ACM Symposium on Operating System Principles (SOSP) (Copper Mountain Resort, Colo., Dec. 1995) ACM Press, 1995, pp. 251--266.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....Mach 3 offers approximately 140 system calls and needs more than 300 Kbytes of code. Reducing a large monolithic kernel may not lead to a real microkernel. Radical New Designs A new radical approach, designing a microkernel architecture from scratch, seemed promising and necessary. Exokernel [9] and L4 [16] discussed here, both concentrate on a minimal and clean new architecture and support highly extensible operating systems. Exokernel. Exokernel, developed at MIT in 199495, is a small, hardware dependent microkernel based on the idea that abstractions are costly and restrict ....

....[16] discussed here, both concentrate on a minimal and clean new architecture and support highly extensible operating systems. Exokernel. Exokernel, developed at MIT in 199495, is a small, hardware dependent microkernel based on the idea that abstractions are costly and restrict flexibility [9]. The microkernel should multiplex hardware primitives in a secure way. The current exokernel, which is tailored to the Mips architecture and gets excellent performance for kernel primitives, is based on the philosophy that a kernel should provide no abstractions but only a minimal set of ....

Engler, D., Kaashoek, M.F., and O'Toole, J. Exokernel, an operating system architecture for application-level resource management. In Proceedings of the 15th ACM Symposium on Operating System Principles (SOSP) (Copper Mountain Resort, Colo., Dec. 1995) ACM Press, 1995, pp. 251--266.

....future applications and OSs is unknown and (d) policy integration enlarges the kernel and thus costs performance. 2. Only basic mechanisms in the kernel, no policies If the mechanisms are general and powerful enough, they should permit to implement any reasonable policy. For example, Exokernel [Engler et al. 1995] and L4 [Liedtke 1995] presently explore this strategy. Making the kernel extensible like in the Spin OS [Bershad et al. 1995] belongs to the second category. There is no real conceptional difference between extending the kernel code by a user written handler and extending the system at ....

Engler, D., Kaashoek, M. F., and O'Toole, J. 1995. Exokernel, an operating system architecture for application-level resource management. In 15th ACM Symposium on Operating System Principles (SOSP), Copper Mountain Resort, CO, pp. 251--266.

....Mach (black white) Costs, 486 DX50. Perhaps reducing a large monolithic kernel does not lead to a real kernel New Radical Designs A new radical (from Latin radicalis: from the root ) approach, designing a kernel architecture from scratch, seemed promising and necessary. We discuss Exokernel [9] and L4 [16] which both concentrate on a minimal and clean new architecture and support highly extensible operating systems. Exokernel developed at MIT is a small and hardware dependent kernel. It is based on the thesis that ffl Abstractions are costly and restrict flexibility. The kernel ....

Engler, D., Kaashoek, M. F., and O'Toole, J. Exokernel, an operating system architecture for application-level resource management. In 15th ACM Symposium on Operating System Principles (SOSP), pages 251--266, Copper Mountain Resort, CO, December 1995.

....System calls are avoided by allowing direct access to the NIC registers and storage areas, thus achieving a closer integration between applications and interconnection networks. This approach is rooted in the idea of F Bufs [DP93] which was followed also in the Exokernel OS architecture [EKO95] Indeed the user level communication architecture shares the same fundamental idea of OS microkernels, that is moving OS services away from the kernel. Often (but not always) a primary challenge besides efficiency is to provide direct access to the communication device without violating the OS ....

D. Engler, M. Kaashoek, and J. O'Toole. Exokernel, an Operating System Architecture for Application-level Resorce Management. In Proc. of the 15th ACM Symp. on Operating Systems Principles (SOSP'95), December 1995.

....minimized. System calls are avoided by allowing direct access to the NIC registers and storage areas, thus achieving a closer integration between applications and interconnection networks. This approach is rooted in the idea of F Bufs [37] which was followed also in the Exokernel OS architecture [38]. Indeed the user level communication architecture shares the same fundamental idea of OS microkernels, that is moving OS services away from the kernel. Often (but not always) a primary challenge besides efficiency is to provide direct access to the communication device without violating the OS ....

D. Engler, M. Kaashoek, and J. O'Toole. Exokernel, an Operating System Architecture for Application-level Resorce Management. In Proc. of the 15th ACM Symp. on Operating Systems Principles (SOSP'95), December 1995.

....brilliant performance. The same idea has been followed with HPAM [6] on a FDDI network of HP 9000 735 workstations and with Illinois Fast Messages [7] on a Myrinet network. The U Net project [11] follows the approach, earlier proposed in [2] and also exploited in the framework of Exokernel [3], of removing communication support from the OS kernel in order to re implement it more efficiently at the user application level. A fixed number of virtual end points are multiplexed over the NIC. Each end point can be attached to a single user process by means of a system call. This way user ....

D. Engler, M. Kaashoek, and J. O'Toole. Exokernel, an Operating System Architecture for Application-level Resorce Management. In Proc. of the 15th ACM Symp. on Operating Systems Principles (SOSP'95), December 1995.

....buffers of the network interface is granted without invoking any system calls. Any communication layer as well as standard interface is implemented as a user level programming library. This approach is rooted in the idea of F Bufs [20] which was followed also in the Exokernel OS architecture [21]. Often (but not always) a primary concern besides efficiency is to provide such a direct access to the communication device without violating the OS protection model. In all the existing instances of such approach, a non standard programming interface is presented to applications. The choice of ....

D. Engler, M. Kaashoek, and J. O'Toole. Exokernel, an Operating System Architecture for Application-level Resorce Management. In Proc. of the 15th ACM Symp. on Operating Systems Principles (SOSP'95), December 1995.

....or Mach) or systematically. Various means were invented to protect kernels from misbehaving extensions, ranging from the use of safe languages [5] to expensive transaction like schemes [34] The too high faction started building kernels resembling a hardware architecture at their interface [12]. Software abstractions have to be built on top of that. It is claimed that kernels can be fast on a given architecture but cannot be moved to other architectures without losing much of their efficiency [19] In contrast, we investigate the pure kernel approach by systematically repeating ....

....L4 was originally designed for, the kernel was reimplemented from scratch on an Alpha 21164, preserving the original L4 interface. Starting from the IPC implementation in L4 Alpha, we also implemented a lower level communication primitive, similar to Exokernel s protected control transfer [12], to find out whether and to what extent the L4 IPC abstraction can be outperformed by a lower level primitive. After a short overview of L4 in Section 3, Section 4 explains the design and implementation of our Linux server. Section 5 then presents and analyzes the system s performance for pure ....

[Article contains additional citation context not shown here]

D. Engler, M. F. Kaashoek, and J O'Toole. Exokernel, an operating system architecture for application-level resource management. In 15th ACM Symposium on Operating System Principles (SOSP), pages 251--266, Copper Mountain Resort, CO, December 1995.

..... This is the principle of independence: S can give guarantees independent of S 0 . The second requirement is that other subsystems 2 Short user to user cross address space IPC in L3 [Liedtke 1993] is 22 times faster than in Mach, both running on a 486. On the R2000, the specialized Exo tlrpc [Engler et al. 1995] is 30 times faster than Mach s general RPC. 3 Proving minimality, necessarity and completeness would be nice but is impossible, since there is no agreed upon metric and all is Turing equivalent. must be able to rely on these guarantees. This is the principle of integrity: there must be a way ....

.... and that the costs are heavily influenced by the processor architecture: Spring on Sparc has to deal with register 8 The respective data is taken from [Liedtke 1993; Hildebrand 1992; Schroeder and Burroughs 1989; Draves et al. 1991; van Renesse et al. 1988; Liedtke 1993; Bershad et al. 1995; Engler et al. 1995; Hamilton and Kougiouris 1993; Bryce and Muller 1995; Bershad et al. 1989] windows, whereas L3 is burdened by the fact that a 486 trap is 100 cycles more expensive than a Sparc trap. The effect of using segment based address space switch on Pentium is shown in figure 2. One long running ....

[Article contains additional citation context not shown here]

Engler, D., Kaashoek, M. F., and O'Toole, J. 1995. Exokernel, an operating system architecture for application-level resource management.

....from the OS kernel to the device is unfeasible with commodity low cost components which usually are not programmable. A well kown representative of the user level approach is U Net. The U Net approach is rooted in the idea of F Bufs [5] which was followed also in the Exokernel OS architecture [6]: User processes are given direct protected access to the network device with no virtualization. Any communication layer as well as standard interface must move to user level programming libraries. U Net runs on an ATM network of SPARCstations [19] as well as on a Fast Ethernet network of Pentium ....

D. Engler, M. Kaashoek, and J. O'Toole. Exokernel, an Operating System Architecture for Applicationlevel Resorce Management. In Proc. of the 15th ACM Symp. on Operating Systems Principles (SOSP'95), December 1995.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC