Wait-free shared-memory irradiance cache
Dubla, Piotr, Debattista, Kurt, Santos, Luis and Chalmers, Alan (2009) Wait-free shared-memory irradiance cache. In: Debattista, Kurt and Weiskopf, D. and Comba, J. and Fellner, D. W., (eds.) EG PGV 2009 : 9th eurographics symposium on parallel graphics and visualization : Munich, Germany : March 29-30, 2009. Aire-la-Ville, Switzerland: Eurographics Association, pp. 57-64. ISBN 9783905674156Full text not available from this repository.
Official URL: http://dx.doi.org/10.2312/EGPGV/EGPGV09/057-064
The irradiance cache (IC) is an acceleration data structure which caches indirect diffuse irradiance values within the context of a ray tracing algorithm. In multi-threaded shared memory parallel systems the IC must be shared among rendering threads in order to achieve high efficiency levels. Since all threads read and write from it an access control mechanism is required, which ensures that the data structure is not corrupted. Besides assuring correct accesses to the IC this access mechanism must incur minimal overheads such that performance is not compromised. In this paper we propose a new wait-free access mechanism to the shared irradiance cache. Wait-free data struc- tures, unlike traditional access control mechanisms, do not make use of any blocking or busy waiting, avoiding most serialisation and reducing contention. We compare this technique with two other classical approaches: a lock based mechanism and a local write technique, where each thread maintains its own cache of locally evaluated irradiance values. We demonstrate that the wait-free approach significantly reduces synchronisation overheads compared to the two other approaches and that it increases data sharing over the local copy technique. This is, to the extent of our knowledge, the first work explicitly addressing access to a shared IC; this problem is becoming more and more relevant with the advent of multicore systems and the ever increasing number of processors within these systems.
|Item Type:||Book Item|
|Divisions:||Faculty of Science > WMG (Formerly the Warwick Manufacturing Group)|
|Place of Publication:||Aire-la-Ville, Switzerland|
|Book Title:||EG PGV 2009 : 9th eurographics symposium on parallel graphics and visualization : Munich, Germany : March 29-30, 2009|
|Editor:||Debattista, Kurt and Weiskopf, D. and Comba, J. and Fellner, D. W.|
|Number of Pages:||114|
|Page Range:||pp. 57-64|
|Access rights to Published version:||Restricted or Subscription Access|
Eurographics Symposium Proceedings
Actions (login required)