Kris Venstermans

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SUMMARY The Java language is popular because of its platform independence, making it useful in a lot of technologies ranging from embedded devices to high-performance systems. The platform-independent property of Java, which is visible at the Java bytecode level, is only made possible thanks to the availability of a Virtual Machine (VM), which needs to be(More)
This paper shows that Appel-style garbage collectors often make suboptimal decisions both in terms of when and how to collect. We argue that garbage collection should be done when the amount of live bytes is low (in order to minimize the collection cost) and when the amount of dead objects is high (in order to maximize the available heap size after(More)
Memory performance is an important design issue for contemporary computer systems given the huge processor/memory speed gap. This paper proposes a space-efficient Java object model for reducing the memory consumption of 64-bit Java virtual machines. We completely eliminate the object header through typed virtual addressing (TVA) or implicit typing. TVA(More)
— The platform-agnostic nature of Java is made possible thanks to the presence of the Java Virtual Machine (JVM) with a well defined set of bytecodes and library routines. This requires the availability of a JVM for many different platforms, 32-bit as well as 64-bit wide. During an effort to port the Jikes Research Virtual Machine (RVM) to the 64-bit(More)
64-bit address spaces come at the price of pointers requiring twice as much memory as 32-bit address spaces, resulting in increased memory usage. Increased memory usage is especially of concern on machines that are heavily loaded with memory-intensive applications; overall system performance can quickly deteriorate once physical memory is exhausted. This(More)
Memory performance is an important design issue for contemporary systems given the ever increasing memory gap. This paper proposes a space-efficient Java object model for reducing the memory consumption of 64-bit Java virtual machines. We propose Selective Typed Virtual Addressing (STVA) which uses typed virtual addressing (TVA) or implicit typing for(More)
In this paper, we present a performance model for Java applications that allows us to determine the relative performance of the same application on two different platforms. During the execution of Java applications, there is a complex interation between the application, the virtual machine, the operating system and the hardware. As such, an execution(More)
— The platform-agnostic nature of Java is made possible thanks to the presence of the Java Virtual Machine (JVM) with a well defined set of bytecodes and library routines. This requires the availability of a JVM for many different platforms, 32-bit as well as 64-bit wide. We believe however that some aspects of the Java SPEC are designed too specific for a(More)
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