A hierarchical model of data locality

Chengliang Zhang, Chen Ding, Mitsunori Ogihara, Yutao Zhong, Youfeng Wu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Scopus citations


In POPL 2002, Petrank and Rawitz showed a universal result-finding optimal data placement is not only NP-hard but also impossible to approximate within a constant factor if P ≠ NP. Here we study a recently published concept called reference affinity, which characterizes a group of data that are always accessed together in computation. On the theoretical side, we give the complexity for finding reference affinity in program traces, using a novel reduction that converts the notion of distance into satisfiability. We also prove that reference affinity automatically captures the hierarchical locality in divide-and-conquer computations including matrix solvers and N-body simulation. The proof establishes formal links between computation patterns in time and locality relations in space. On the practical side, we show that efficient heuristics exist. In particular, we present a sampling method and show that it is more effective than the previously published technique, especially for data that are often but not always accessed together. We show the effect on generated and real traces. These theoretical and empirical results demonstrate that effective data placement is still attainable in general-purpose programs because common (albeit not all) locality patterns can be precisely modeled and efficiently analyzed.

Original languageEnglish (US)
Title of host publicationConference Record of POPL 2006
Subtitle of host publication33rd ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages
PublisherAssociation for Computing Machinery
Number of pages14
ISBN (Print)1595930272, 9781595930279
StatePublished - 2006
Externally publishedYes
Event33rd ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL'06 - Charleston, SC, United States
Duration: Jan 11 2006Jan 13 2006

Publication series

NameConference Record of the Annual ACM Symposium on Principles of Programming Languages
ISSN (Print)0730-8566


Conference33rd ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL'06
Country/TerritoryUnited States
CityCharleston, SC


  • Hierarchical data placement
  • N-body simulation
  • NP-complete
  • Program locality
  • Reterence affinity
  • Volume distance

ASJC Scopus subject areas

  • Software


Dive into the research topics of 'A hierarchical model of data locality'. Together they form a unique fingerprint.

Cite this