carla@macbeth.cs.duke.edu (Carla Ellis) (06/01/90)
We would like to announce the availability of the following technical
report that describes measurements taken with our DUnX kernel comparing
various page migration and replication policies:
Experimental Comparison of Memory Management Policies for
NUMA Multiprocessors
Richard P. LaRowe Jr. and Carla Schlatter Ellis
Department of Computer Science
Duke University
Durham, NC 27706
April 1990
CS-1990-10
ABSTRACT
Non-uniformity of memory access is an almost
inevitable feature of the memory architecture in
shared memory multiprocessor designs that can
scale to large numbers of processors. One impli-
cation of NUMA architectures is that the placement
and movement of code and data become crucial to
performance. As memory architectures become more
complex and the non-uniformity becomes less well
hidden, system software must assume a larger role
in providing memory management support for the
programmer. This paper investigates the role of
the operating system.
We take an experimental approach to evaluat-
ing a wide-range of memory management policies.
The target NUMA environment is BBN's GP-1000 mul-
tiprocessor. Extensive local modifications have
been made to the memory management subsystem of
BBN's nX operating system to support multiple pol-
icy implementations. Policy comparisons are based
on the measured performance of real parallel
applications.
Our results show that there are memory
management policies implemented in our system that
can improve the performance of programs written
using the simpler uniform memory access (UMA) pro-
gramming model. While achieving the level of per-
formance of a highly tuned NUMA program is still a
difficult problem, some examples come close.
There appears to be no single policy that can be
considered the best over our set of test applica-
tions. Investigations into the contributions made
by individual policy features toward overall
behavior of the workload provides some insight
into the design of a set of effective policies.
DETAILS ON HOW TO ACQUIRE REPORT
The technical report described above is available for
anonymous ftp from cs.duke.edu (128.109.140.1)
It is a compressed postscript file in /pub
called DUnX-TR.ps.Z
To get a hardcopy version via USmail send a request for
TR CS-1990-10 to
carla@cs.duke.edu or rpl@cs.duke.edu.
Also please send any comments or questions you have
after reading the report.