Re-Architecting Mass Storage Input/Output for Performance and Efficiency

The semantics and fundamental structure of modern operating system IO systems dates from the mid-1960\u27s to the mid-1970\u27s, a period of time when computing power and memory capacity were a mere fraction of today\u27s systems. Engineering tradeoffs made in the past enshrine the resource availability context of computing at that time. Deconstructing the semantics of the IO infrastructure allows a re-examination of long-standing design decisions in the context of today\u27s greater processing and memory resources. The re-examination allows changes to several wide-spread paradigms to improve efficiency and performance

Design and evaluation of the Hamal parallel computer

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2003."December 2002."Includes bibliographical references (p. 145-152).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Parallel shared-memory machines with hundreds or thousands of processor-memory nodes have been built; in the future we will see machines with millions or even billions of nodes. Associated with such large systems is a new set of design challenges. Many problems must be addressed by an architecture in order for it to be successful; of these, we focus on three in particular. First, a scalable memory system is required. Second, the network messaging protocol must be fault-tolerant. Third, the overheads of thread creation, thread management and synchronization must be extremely low. This thesis presents the complete system design for Hamal, a shared-memory architecture which addresses these concerns and is directly scalable to one million nodes. Virtual memory and distributed objects are implemented in a manner that requires neither inter-node synchronization nor the storage of globally coherent translations at each node. We develop a lightweight fault-tolerant messaging protocol that guarantees message delivery and idempotence across a discarding network. A number of hardware mechanisms provide efficient support for massive multithreading and fine-grained synchronization.(cont.) Experiments are conducted in simulation, using a trace-driven network simulator to investigate the messaging protocol and a cycle-accurate simulator to evaluate the Hamal architecture. We determine implementation parameters for the messaging protocol which optimize performance. A discarding network is easier to design and can be clocked at a higher rate, and we find that with this protocol its performance can approach that of a non-discarding network. Our simulations of Hamal demonstrate the effectiveness of its thread management and synchronization primitives. In particular, we find register-based synchronization to be an extremely efficient mechanism which can be used to implement a software barrier with a latency of only 523 cycles on a 512 node machine.by J.B. Grossman.Ph.D

Design and Evaluation of the Hamal Parallel Computer

Parallel shared-memory machines with hundreds or thousands of processor-memory nodes have been built; in the future we will see machines with millions or even billions of nodes. Associated with such large systems is a new set of design challenges. Many problems must be addressed by an architecture in order for it to be successful; of these, we focus on three in particular. First, a scalable memory system is required. Second, the network messaging protocol must be fault-tolerant. Third, the overheads of thread creation, thread management and synchronization must be extremely low. This thesis presents the complete system design for Hamal, a shared-memory architecture which addresses these concerns and is directly scalable to one million nodes. Virtual memory and distributed objects are implemented in a manner that requires neither inter-node synchronization nor the storage of globally coherent translations at each node. We develop a lightweight fault-tolerant messaging protocol that guarantees message delivery and idempotence across a discarding network. A number of hardware mechanisms provide efficient support for massive multithreading and fine-grained synchronization. Experiments are conducted in simulation, using a trace-driven network simulator to investigate the messaging protocol and a cycle-accurate simulator to evaluate the Hamal architecture. We determine implementation parameters for the messaging protocol which optimize performance. A discarding network is easier to design and can be clocked at a higher rate, and we find that with this protocol its performance can approach that of a non-discarding network. Our simulations of Hamal demonstrate the effectiveness of its thread management and synchronization primitives. In particular, we find register-based synchronization to be an extremely efficient mechanism which can be used to implement a software barrier with a latency of only 523 cycles on a 512 node machine

NBS monograph

From Introduction: "This is the second in a series of reports concerned with research and development requirements and areas of continuing concern in the computer and information sciences and technologies.

Computer and data security: a comprehensive annotated bibliography.

Massachusetts Institute of Technology, Alfred P. Sloan School of Management. Thesis. 1973. M.S.MICROFICHE COPY ALSO AVAILABLE IN DEWEY LIBRARY.M.S

Link aggregation approach to a microkernel operating system

Teza se bavi povećanjem ukupne oslonljivosti modularnog mikrokernel operativnog sistem MINIX 3 kroz povećanje pouzdanosti njegovog mrežnog podsistema. To je postignuto tako što je ovom operativnom sistemu dodata agregacija mrežnih veza, čime je podražana tolerancija na poremećaj komunikacionih linija. Na kraju je data analiza kako dodati deo utiče na ukupne mrežne performanse.The thesis deals with the way to increase the dependability of the modular microkernel operating system MINIX 3 through the increase of the reliability of its network subsystem. This is achieved by adding link aggregation to this operating system, which added fault tolerance for the communication lines. At the end, the analysis is given of how new module affects the overall network performance