Title
A study of the scalability of stop-the-world garbage collectors on multicores
Abstract
Large-scale multicore architectures create new challenges for garbage collectors (GCs). In particular, throughput-oriented stop-the-world algorithms demonstrate good performance with a small number of cores, but have been shown to degrade badly beyond approximately 8 cores on a 48-core with OpenJDK 7. This negative result raises the question whether the stop-the-world design has intrinsic limitations that would require a radically different approach. Our study suggests that the answer is no, and that there is no compelling scalability reason to discard the existing highly-optimised throughput-oriented GC code on contemporary hardware. This paper studies the default throughput-oriented garbage collector of OpenJDK 7, called Parallel Scavenge. We identify its bottlenecks, and show how to eliminate them using well-established parallel programming techniques. On the SPECjbb2005, SPECjvm2008 and DaCapo 9.12 benchmarks, the improved GC matches the performance of Parallel Scavenge at low core count, but scales well, up to 48~cores.
Year
DOI
Venue
2013
10.1145/2490301.2451142
Special Interest Group on Computer Architecture
Keywords
DocType
Volume
garbage collection,multicore,numa
Conference
41
Issue
ISSN
Citations 
1
0163-5964
21
PageRank 
References 
Authors
0.76
20
4
Name
Order
Citations
PageRank
Lokesh Gidra1522.14
Gaël Thomas225616.95
Julien Sopena314018.04
marc shapiro4421.50