Ph.D. Alumni: David Kar Fai Tam
Reference:
David Kar Fai Tam
Operating System Management of Shared Caches on Multicore Processors
Ph.D. Thesis, Department of Electrical and Computer Engineering, University of Toronto, Toronto, Canada, 2010.
Supervisor(s):
Michael Stumm
Download Thesis:
Abstract:
Our thesis is that operating systems should manage the on-chip shared caches of multicore processors for the purposes of achieving performance gains. Consequently, this dissertation demonstrates how the operating system can profitably manage these shared caches. Two shared-cache management principles are investigated: (1) promoting shared use of the shared cache, demonstrated by an automated online thread clustering technique, and (2) providing cache space isolation, demonstrated by a software-based cache partitioning technique. In support of providing isolation, cache provisioning is also investigated, demonstrated by an automated online technique called RapidMRC. We show how these software-based techniques are feasible on existing multicore systems with the help of their hardware performance monitoring units and their associated hardware performance counters. On a 2-chip IBM POWER5 multicore system, promoting sharing reduced processor pipeline stalls caused by cross-chip cache accesses by up to 70%, resulting in performance improvements of up to 7%. On a larger 8-chip IBM POWER5+ multicore system, the potential for up to 14% performance improvement was measured. Providing isolation improved performance by up to 50%, using an exhaustive offline search method to determine optimal partition size. On the other hand, up to 2% performance improvement was extracted from the corresponding workload using an automated online approximation technique, made possible by RapidMRC.
Keywords:
Operating systems, multicore processors, shared caches, promoting sharing, providing isolation, cache provisioning, thread clustering, cache partitioning, approximating MRCs, miss-rate curves
BibTeX:
@phdthesis(Tam-PhD10,
author = {David Kar Fai Tam},
title = {Operating System Management of Shared Caches on Multicore Processors},
school = {Department of Electrical and Computer Engineering, University of Toronto},
address = {Toronto, Canada},
supervisors = {Michael Stumm},
month = {September},
year = {2010},
keywords = {Operating systems, multicore processors, shared caches, promoting sharing, providing isolation, cache provisioning, thread clustering, cache partitioning, approximating MRCs, miss-rate curves}
)