Reversible | Kalyan Perumalla

ReveR-SES: Reversible Software Execution Systems

Sat, 01 Jan 2022 00:00:00 +0000

Reversible Software Execution Systems ReveR-SES is a paradigm shift in ultra-scale computing to address the outstanding scaling challenges by enabling an entirely new, orthogonal dimension to all aspects of traditional, forward-only computing.

ReveR-SES

Overview

ReveR-SES not only provides expeditious, novel solutions to scaling problems, but also opens new, longer-term research and development directions in high performance computing.

All traditional computing is done forward-only, but never in reverse order. Only recently it has been discovered that executing codes backwards can be used to greatly increasing the efficiency and usability of high performance computing. However, rendering a program reversible is an extremely challenging endeavor. This project is focused on developing the methodologies to exploit reversibility to enable scaling applications to ultra-scale platforms with 1,000,000 processor cores.

ReveR-SES contains several novel ideas, including reversible compilers, reversible libraries, reversibility extensions to standard interfaces, as well as relation to thermodynamics, information and entropy.

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ReveR-SES Confluence

The reversible execution paradigm represents an entirely new research direction, yet, has immediate relevance to existing DOE applications and also the potential for creation of entirely new technologies and the creation of new high-technology jobs in computing. This is due to the orthogonality of reversibility to many existing HPC dimensions.

ReveR-SES Components

Overall, the new execution paradigm provides energy savings in the short-term and better energy-efficient designs in the longer term. The reversible execution systems are directly relevant to important applications such as climate, plasma physics, and materials science simulations.

ReveR-SES was Dr. Kalyan Perumalla’s Early Career Research project 2010-2015, awarded as a single-principal investigator, $2.5 million project.

https://science.osti.gov/ascr/Community-Resources/ECRP-Awardees

Scope

To define, develop, test, and implement the paradigm of reversible software execution for exascale computing.

Primary Scientific Thrusts

Developing fundamentally new reversible computer arithmetic and logic
Designing efficient asynchronous rollback-based recovery via reversible execution
Redesigning traditional physical system models to enable reversible simulation
Reevaluating theoretical computational and energy consumption interplay.

Science Impacts

Enables new capabilities for computational science common to many areas

Extremely efficient method for fault tolerant simulations on next generation heterogeneous (CPU+GPU) systems
Solves the synchronization problem at very large scales of concurrency
Overcomes undesirable reliance on memory
- Addresses the exascale hardware problem of high ratio of computational speed to memory speed
- Computational energy reduced via reduced memory footprint
Provides the most promising approach to debugging at exascale.

Enables Theoretical Advancements

Directly relates energy of computation to computational model characteristics
Positions scientific simulations for future reversible computing hardware (adiabatic circuits, Quantum Computing).

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Organization

Sponsor: US Department of Energy (DOE)
- Office: Advanced Scientific Computing Research (ASCR)
- Program: Early Career Research Program (ECRP)
Prime: Oak Ridge National Laboratory (ORNL)

Selected Publications

Normalcy, Magic, Miracle and Error: Emergence along a Reversibility Spectrum

Formation of a butterfly from a pupa, extraction of a live dove from a magician’s empty hat, generation of new particles from high-energy particle collisions and spawning a new dream world from mind in sleep are all examples of a common, fuzzy notion called ‘emergence’. In this paper, I pin the concept of emergence to the element of surprise in a phenomenon. I categorise the various notions of emergence into three main classes. These definitions are used to explain instances of emergence, organised along a continuous spectrum as normality, magic, miracle and error.

Kalyan Perumalla

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Efficient reversible uniform and non-uniform random number generation in UNU.RAN

Reversible random number generations are useful in large-scale fault-tolerant parallel computations and parallel discrete event …

Srikanth Yoginath, Kalyan Perumalla

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Towards Reversible Basic Linear Algebra Subprograms: A Performance Study

Problems such as fault tolerance and scalable synchronization can be efficiently solved using reversibility of applications…

Kalyan Perumalla, Srikanth Yoginath

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Reverse Computation for Rollback-based Fault Tolerance in Large Parallel Systems

Reverse computation is presented here as an important future direction in addressing the challenge o…

Kalyan Perumalla, Alfred Park

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Tutorial: Introduction to Reversible Computing

This tutorial provides an introduction to the concept of reversible computing, adopting an expanded view…

Kalyan Perumalla

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Reversibly Finding the Square Root of an Integer

Here we consider a case study in reversible computing, namely, how to reversibly compute the integer square root …

Melissa Yu, Kalyan Perumalla

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Reversible Simulations of Elastic Collisions (Extended arXiv version)

Consider a system of N identical hard spherical particles moving in a d-dimensional box and undergoing elastic, possibly multi-particle, collisions…

Kalyan Perumalla, Vladimir A. Protopopescu

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Reversible Simulations of Elastic Collisions

Consider a system of N identical hard spherical particles moving in a d-dimensional box and undergoi…

Kalyan Perumalla, Vladimir A. Protopopescu

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Introduction to Reversible Computing

Few books comprehensively cover the software and programming aspects of reversible computing. Fillin…

Kalyan Perumalla

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ReveR-SES: Reversible Software Execution Systems

[Pub 137]

Kalyan Perumalla

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Discrete Event Execution and Reversibility: Challenges in the Path to Asynchrony for Massively Parallel Computing

To keep up with the increasing number of processing elements in parallel/distributed computing, traditional tightly-coupled time-stepped models…

Kalyan Perumalla

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Reversible Parallel Discrete Event Formulation of a TLM-based Radio Signal Propagation Model

Radio signal strength estimation is essential in many applications, including the design of military…

Sudip Seal, Kalyan Perumalla

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ReveR-SES: Reversible Software Execution Systems

[Pub 136] http://science.energy.gov/ascr/ascac/meetings/nov-2011/

Kalyan Perumalla

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Reversible Parallel Discrete-Event Execution of Large-scale Epidemic Outbreak Models

The spatial scale, runtime speed, and behavioral detail of epidemic outbreak simulations altogether …

Kalyan Perumalla, Sudip Seal

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Compiler-based Automation Approaches to Reverse Computation

Automation is useful to facilitate reverse code generation from normal code. Here, we describe our …

Kalyan Perumalla, Christopher Carothers

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Reversible Discrete Event Formulation and Optimistic Parallel Execution of Vehicular Traffic Models

Vehicular traffic simulations are useful in applications such as emergency planning and traffic mana…

Kalyan Perumalla, Srikanth Yoginath

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Perfect Reversal of Rejection Sampling Methods for First-Passage-Time and Similar Probability Distributions

We present a perfectly reversible method for bi-directional generation of samples from computational…

Kalyan Perumalla, Aleksandar Donev

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Introduction to Reversible Computing

Sat, 01 Jan 2022 00:00:00 +0000

ISBN 978-1439873403, 1^st Edition | Chapman and Hall/CRC | Taylor&Francis | Amazon
One of the first books on the topic, it contains a compendium of both classical and recently developed results on reversible computing.

About

Introduction to Reversible Computing

This seminal book on reversible computing collects scattered knowledge into one coherent account. It offers an expanded view of the field that includes the traditional energy-motivated hardware viewpoint as well as the emerging application-motivated software approach. It explores up-and-coming theories, techniques, and tools for the application of reversible computing. The topics covered span several areas of computer science, including high-performance computing, parallel/distributed systems, computational theory, compilers, power-aware computing, and supercomputing.

Key Features

Emphasizes the software, programming, application, and usage aspects of reversible computing
Helps readers easily understand complex theoretical and seminal results at a level suitable for senior undergraduate or graduate students
Illustrates the development of reversible code generation using actual code segments in the C language
Provides pseudocodes of several algorithms for memory-less or memory- efficient reversibility, including reversible random number generation and reversible numerical computation
Includes a comprehensive bibliography and resources for further reading

Selected Contents

INTRODUCTION: Scope. Application Areas. The Reversible Computing Spectrum.
THEORY: Systems and Principles. Reversibility-Related Paradoxes. Theoretical Computing Models. Relaxing Forward-Only Execution into Reversible Execution.
SOFTWARE: Reversible Programming Languages. Adding Reversibility to Irreversible Programs. Reverse C Compiler. Reversal of Linear Codes. Reversible Random Number Generation. Reversible Memory Allocation and Deallocation. Reversible Numerical Computation. Reversing a Sorting Procedure. Implementing Undo-Redo-Do.
HARDWARE: Reversible Logic Gates. Reversible Instruction Set Architectures.
SUMMARY: Future Directions.
REFERENCES: Bibliography. Index.