DMCA
Using Object Combining for Object Prefetching in DSM Systems (2004)
| Venue: | In Proc. 11th Workshop on Compilers for Parallel Computers |
| Citations: | 1 - 0 self |
BibTeX
@INPROCEEDINGS{Veldema04usingobject,
author = {Ronald Veldema},
title = {Using Object Combining for Object Prefetching in DSM Systems},
booktitle = {In Proc. 11th Workshop on Compilers for Parallel Computers},
year = {2004}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Abstract Object Combining takes two arbitrary objects and combines them into a single largerobject. This is advantageous for object based distributed shared memory (DSM) systems as only half the number of network latencies is required to ship the combined object instead oftwo to ship two individual objects. As we can combine an object with another object that already has an object combined with it, we can combine arbitrary sets of objects.The problem is to find the right set of objects to combine as combining the wrong set of objects can cause false sharing and severely hurt performance. In this paper we will propose aset of annotations that the programmer can add to his program to select good sets of candidate objects for combining them.The experiments are conducted in Jackal, a fine grained object based DSM for Java programs. The compiler turns an unmodified, multithreaded Java program into an executable thatruns on a cluster of workstations. Using object combining, we could improve performance by up to 20%. 1 Introduction In object based Distributed Shared Memory (DSM) systems, every non-local object access causesan object to be fetched from its home node. Thus, for every object access, two messages need to be sent over the network: a data request message and a data reply message (instead of moretraditional DSM systems where communication occurs for each non-local hardware page). If the network is slow, this causes unacceptable overheads. In our system, Jackal [8], detection of non-local data access is performed by using 'access checks'.An access check is a small piece of (assembly) code inserted before each object access that checks
Keyphrases
object combining object prefetching dsm system object access access check home node false sharing candidate object shared memory arbitrary set wrong set good set individual object unacceptable overhead moretraditional dsm system non-local data access non-local object access causesan object combined object small piece non-local hardware page right set hurt performance multithreaded java program arbitrary object executable thatruns data reply message distributed shared memory single largerobject abstract object combining network latency data request message java program
