Transparent pointer compression for linked data structures

64-bit address spaces are increasingly important for modern applications, but they come at a price: pointers use twice as much memory, reducing the effective cache capacity and memory bandwidth of the system (compared to 32-bit ad-dress spaces). This paper presents a sophisticated, auto-matic transformation that shrinks pointers from 64-bits to 32-bits. The approach is “macroscopic, ” i.e., it operates on an entire logical data structure in the program at a time. It allows an individual data structure instance or even a subset thereof to grow up to 232 bytes in size, and can compress pointers to some data structures but not others. Together, these properties allow efficient usage of a large (64-bit) ad-dress space. We also describe (but have not implemented) a dynamic version of the technique that can transparently expand the pointers in an individual data structure if it ex-ceeds the 4GB limit. For a collection of pointer-intensive benchmarks, we show that the transformation reduces peak heap sizes substantially by (20 % to 2x) for several of these benchmarks, and improves overall performance significantly in some cases

Improving 64-bit Java IPF performance by compressing heap references

64-bit processor architectures like the Intel ® Itanium® Processor Family are designed for large applications that need large memory addresses. When running applications that fit within a 32-bit address space, 64-bit CPUs are at a disadvantage compared to 32-bit CPUs because of the larger memory footprints for their data. This results in worse cache and TLB utilization, and consequently lower performance because of increased miss ratios. This paper considers software techniques for virtual machines that allow 32-bit pointers to be used on 64bit CPUs for managed runtime applications that do not need the full 64-bit address space. We describe our pointer compression techniques and discuss our experience implementing these for Java 1 applications. In addition, we give performance results with our techniques for both the SPEC JVM98 and SPEC JBB2000 benchmarks. We demonstrate a 12 % performance improvement on SPEC JBB2000 and a reduction in the number of garbage collections required for a given heap size. 1

Real-time sound spatialization, software design and implementation.

'Real-time Sound Spatialization, Software Design and Implementation' explores real-time spatialization signal processing for the sound artist. The thesis is based around the production of two prototype software projects, both of which are examined in design and implementation. The first project examines a conceptual method for performance based spatialization mixing which aims to expand existing analogue designs. 'Super Diffuse' , proven performance grade software and the encompassing M2 system, is submitted, for model evaluation and example. The second project focuses on Physical Modelling Synthesis and introduces 'Source Ray Pickup Interactions' as a tool for packaging real-time spatialization digital signal processing. Submitted with the theoretical model is the 'Ricochet' software, an implementation of 'Source Ray Pickup Interaction'. 'Ricochet' serves as a model evaluation tool and example of implementation

Intelligent Management of Virtualised Computer Based Workloads and Systems

Managing the complexity within virtualised IT infrastructure platforms is a common problem for many organisations today. Computer systems are often highly consolidated into a relatively small physical footprint compared with previous decades prior to late 2000s, so much thought, planning and control is necessary to effectively operate such systems within the enterprise computing space. With the development of private, hybrid and public cloud utility computing this has become even more relevant; this work examines how such cloud systems are using virtualisation technology and embedded software to leverage advantages, and it uses a fresh approach of developing and creating an Intelligent decision engine (expert system). Its aim is to help reduce the complexity of managing virtualised computer-based platforms, through tight integration, high-levels of automation to minimise human inputs, errors, and enforce standards and consistency, in order to achieve better management and control. The thesis investigates whether an expert system known as the Intelligent Decision Engine (IDE) could aid the management of virtualised computer-based platforms. Through conducting a series of mixed quantitative and qualitative experiments in the areas of research, the initial findings and evaluation are presented in detail, using repeatable and observable processes and provide detailed analysis on the recorded outputs. The results of the investigation establish the advantages of using the IDE (expert system) to achieve the goal of reducing the complexity of managing virtualised computer-based platforms. In each detailed area examined, it is demonstrated how using a global management approach in combination with VM provisioning, migration, failover, and system resource controls can create a powerful autonomous system