Protection in the Think exokernel

In this paper, we present our preliminary ideas concerning the adaptation of security and protection techniques in the Think exokernel. Think is our proposition of a distributed adaptable kernel, designed according to the exokernel architecture. After summing up the main motivations for using the exokernel architecture, we describe the Think exokernel as it has been implemented on a PowerPC machine. We then present the major protection and security techniques that we plan to adapt to the Think environment, and give an example of how some of these techniques can be combined with the Think model to provide fair and protected resource management. Finally, we briefly present the iPAQ Pocket PC to which we plan to port the Think exokernel and explain our interest in this kind of mobile devices

Trusted Collaborative Real Time Scheduling in a Smart Card Exokernel

This paper presents the work we have conducted concerning real time scheduling in Camille, an exokernel dedicated to smart cards. We show that it is possible to embedded a flexible real-time operating system despite the important hardware limitations of the smart card platform. We present the major difficulties one has to face when integrating real time support in an exokernel embedded on a very resource-limited platform. We first present a naive solution consisting in allocating an equal time slice to every system extensions and letting each one share it as needed amongst its tasks. We show that this solution does not account for loading of new extensions in the system, and that it can fail if some extensions have much more work to carry out than the others. We then present a more complex solution based upon collaborative schedulers grouped as virtual extensions. We show that this solution supports dynamic loading of new extensions and works even for very unbalanced task repartitions. We finally address the issue of trust between the collaborating extensions and we propose a solution based on exhaustive testing and formal proving of the plan functions

Idle Period Propagation in Message-Passing Applications

Idle periods on different processes of Message Passing applications are unavoidable. While the origin of idle periods on a single process is well understood as the effect of system and architectural random delays, yet it is unclear how these idle periods propagate from one process to another. It is important to understand idle period propagation in Message Passing applications as it allows application developers to design communication patterns avoiding idle period propagation and the consequent performance degradation in their applications. To understand idle period propagation, we introduce a methodology to trace idle periods when a process is waiting for data from a remote delayed process in MPI applications. We apply this technique in an MPI application that solves the heat equation to study idle period propagation on three different systems. We confirm that idle periods move between processes in the form of waves and that there are different stages in idle period propagation. Our methodology enables us to identify a self-synchronization phenomenon that occurs on two systems where some processes run slower than the other processes.Comment: 18th International Conference on High Performance Computing and Communications, IEEE, 201

Snowflake: Spanning administrative domains

Many distributed systems provide a ``single-system image\u27\u27 to their users, so the user has the illusion that they are using a single system when in fact they are using many distributed resources. It is a powerful abstraction that helps users to manage the complexity of using distributed resources. The goal of the Snowflake project is to discover how single-system images can be made to span administrative domains. Our current prototype organizes resources in namespaces and distributes them using Java Remote Method Invocation. Challenging issues include how much flexibility should be built into the namespace interface, and how transparent the network and persistent storage should be. We outline future work on making Snowflake administrator-friendly

Applying exokernel principles to conventional operating systems

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 51-52).by John Jannotti.M.Eng

Hey, You Got Your Language In My Operating System!

Several projects in the operating systems research community suggest a trend of convergence among features once divided between operating systems and languages. We describe how partial evaluation and transformational programming systems apply to this trend by providing a general framework for application support, from compilation to run-time services. We contend that the community will no longer think of implementing a static collection of services and calling it an operating system; instead, this general framework will allow applications to be flexibly configured, and the ``operating system\u27\u27 will simply be the application support that is supplied at run-time

Should machines be tools or tool-users? Clarifying motivations and assumptions in the quest for superintelligence

Much of the basic non-technical vocabulary of artificial intelligence is surprisingly ambiguous. Some key terms with unclear meanings include intelligence, embodiment, simulation, mind, consciousness, perception, value, goal, agent, knowledge, belief, optimality, friendliness, containment, machine and thinking. Much of this vocabulary is naively borrowed from the realm of conscious human experience to apply to a theoretical notion of “mind-in-general” based on computation. However, if there is indeed a threshold between mechanical tool and autonomous agent (and a tipping point for singularity), projecting human conscious-level notions into the operations of computers creates confusion and makes it harder to identify the nature and location of that threshold. There is confusion, in particular, about how—and even whether—various capabilities deemed intelligent relate to human consciousness. This suggests that insufficient thought has been given to very fundamental concepts—a dangerous state of affairs, given the intrinsic power of the technology. It also suggests that research in the area of artificial general intelligence may unwittingly be (mis)guided by unconscious motivations and assumptions. While it might be inconsequential if philosophers get it wrong (or fail to agree on what is right), it could be devastating if AI developers, corporations, and governments follow suit. It therefore seems worthwhile to try to clarify some fundamental notions

Adding a Flow-Oriented Paradigm to Commodity Operating Systems

The speed of CPUs and memories has historically outstripped I/O, but emerging network and storage technologies promise to invert this relationship. As a result, fundamental assumptions about the role of the operating system in computing systems will have to change. We propose an operating and application architecture that removes the CPU and memory from the path of high-speed I/O. In our model, the operating system becomes a data-flow manager and applications merely direct this flow instead of directly participating in it. Our proof-of-concept prototype, which we implemented on an FPGA board, nearly doubled the throughput of a simple cryptographic networking application, suggesting our model can provide a substantial improvement