A Prefetching Technique for Irregular Accesses to Linked Data Structures

Prefetching offers the potential to improve the performance of linked data structure (LDS) traversals. However, previously proposed prefetching methods only work well when there is enough work processing a node that the prefetch latency can be hidden, or when the LDS is long enough and the traversal path is known a priori. This paper presents a prefetching technique called prefetch arrays which can prefetch both short LDS, as the lists found in hash tables, and trees when the traversal path is not known a priori. We offer two implementations, one software-only and one which combines software annotations with a prefetch engine in hardware. On a pointer-intensive benchmark suite, we show that our implementations reduce the memory stall time by 23% to 51% for the kernels with linked lists, while the other prefetching methods cause reductions that are substantially less. For binary-trees, our hardware method manages to cut nearly 60% of the memory stall time even when the traversal path i...

• Type: Conference
• Year: 2000
• Where: HPCA
• Authors: Magnus Karlsson, Fredrik Dahlgren, Per Stenström
• Keywords: Distributed And Parallel Computing, HPCA 2000, Linked Data Structure, Memory Stall Time, Traversal Path