Title
FastCollect: offloading generational garbage collection to integrated GPUs
Abstract
Generational Mark-Sweep Garbage Collection is a widely used garbage collection technique. However, the garbage collector has poor execution efficiency for large programs. Aggressive collection causes execution pauses in the program, while reducing the collection frequency leads to memory wastage. In this work, we develop FastCollect, a parallel version of the generational mark-sweep garbage collector running on a graphics processing unit (GPU). At the core of our parallel implementation lies a parallel Depth First Search using a space-efficient concurrent stack, which we develop for the young and the mature garbage collection. To further improve performance, (i) we reduce thread-divergence and improve load-balancing by devising a distributed work-stealing approach, (ii) we optimize our garbage collection algorithm to reduce the number of atomic instructions, (iii) we exploit the memory hierarchy to design a hybrid stack, and (iv) we extract multiple adjacent objects simultaneously by exploiting vectorized memory accesses. We implemented FastCollect in Java Hotspot VM and evaluated our results by executing DaCapo benchmarks. FastCollect is 4-5x faster than the Parallel Hotspot garbage collector and 42% faster than a previous GPU implementation. In addition, while the existing GPU version requires memory linear in the number of compute units, FastCollect's memory requirement is fixed and low. FastCollect not only improves execution time of garbage collection, but also relieves the CPU for improved user interaction.
Year
DOI
Venue
2016
10.1145/2968455.2968520
ESWEEK'16: TWELFTH EMBEDDED SYSTEM WEEK Pittsburgh Pennsylvania October, 2016
Keywords
Field
DocType
generational garbage collection, mark and sweep garbage collection, parallel garbage collection, SIMT, GPU
Garbage,Manual memory management,Computer science,Mark-compact algorithm,Parallel computing,Real-time computing,Memory management,Hazard pointer,Garbage collection,Region-based memory management,Memory leak,Operating system
Conference
ISBN
Citations 
PageRank 
978-1-4503-4482-1
0
0.34
References 
Authors
15
2
Name
Order
Citations
PageRank
Abhinav100.34
Rupesh Nasre234121.02