Karl Taht's Research Paper Blog

Authors: Kostis Kaffes, Timothy Chong, Jack Tigar Humphries, Adam Belay, David Mazieres, Christos Kozyrakis Venue: NSDI 2019 Shinjuku is a dataplane operating system that leverages hardware support for virtualization to enable microsecond-scale preemption. In network processing, there is a fundamental challenge between optimizing for throughput and latency. Interrupt cores too frequently, and throughput will drop because of context switching overheads. Conversely, infrequent preemption can lead to poor tail latency, as short requests can get stuck behind long requests. This is particularly prevalent in bimodal distributions -- such as DB server processing short get() and put() requests while also servicing scans. Shinjuku first greatly reduces context switching overhead by leveraging Dune, enabling direct access to APICs, and other optimizations. With low-overhead context swap enabled, the authors then focus on an effective preemptive scheduling algorithms. The authors utilize cen...

Authors: Dawson R. Engler, M. Frans Kaashoek, James O'Toole Jr. Venue:    SOSP 1995 This work presents a solution to a fundamental constraint of modern operations: that generality degrades performance, or conversely, that the lower level of a primitive, the more efficiently it can be implemented. The exokernel operating systems centralizes around a single goal: separating protection of management. The exokernel itself, Aegis, utilizes secure bindings, visible resource revocation, and an abort protocol to handle protections. However, low level interfaces are exposed so that "library operating systems" can efficiently implement abstractions tailored to their needs. Some examples of this are explicit memory management, custom IPC (inter-process communication), and exception handling. The details of how this is achieved I would describe as "less than straight forward", however, there are extensive resources describing it further, such as this book . I think more ...