Abstract:
Performance Isolation:
Sharing and Isolation in Shared-Memory Multiprocessors
Shared-memory multiprocessors (SMPs) are being exten
sively used as general-purpose servers. The tight coupling of
multiple processors, memory, and I/O provides enormous
computing power in a single system, and enables the effi
cient sharing of these resources.
The operating systems for these machines (UNIX or Win
dows NT) provide very few controls for sharing the
resources of the system among the active tasks or users. This
unconstrained sharing model is a serious limitation for a
server because the load placed by one user can adversely
affect other users' performance in an unpredictable manner.
We show that this lack of isolation is caused by the resource
allocation scheme (or lack thereof) carried over from single-
user workstations. Multi-user multiprocessor systems
require more sophisticated resource management, and we
show how the proposed "performance isolation" scheme can
address the current weaknesses of these systems. We have
implemented performance isolation in the Silicon Graphics
IRIX operating system for three important system resources:
CPU time, memory, and disk bandwidth. Running a number
of workloads we show that our proposed scheme is success
ful at providing workstation-like isolation under heavy load,
SMP-like latency under light load, and SMP-like throughput
in all cases
Hive home page
FLASH home page
Last modified 3/4/95 by
Ben Verghese,
webmaster@www-flash.stanford.edu.
