Paper Evaluations

Kiran Tati (ktati@csag.ucsd.edu)
Thu, 20 Apr 2000 08:46:57 -0700

Start OS:
The major goal of this paper is to provide an environment
to exploit the parallelism available in the cm* multiprocessor machine.
The
natural solution to exploit parallelism is to sub divide the entire task

and try to run as many sub tasks as parallel. This is the approach of
this operating system by supporting a notion called Task forces. Since
many processes are running parallax to achieve a single goal, it is
necessary
to have a good inter process communication. So StarOS provide mail box
based communication mechanism for inter process communication. A special

language TASK is supported to ease the specification of task force. Each

Task force is implemented by a set of modules which in turn may contain
some
objects which provide the functionality of the module and has some state

associated with each object. Basically the module provide an interface
for other modules to use its functionality. It would be very interesting

if the paper include more information about the structure of the
operating
system rather than what functionality it is providing for the user. I
think
this aspect is well covered in the next paper Medusa.

Medusa:
The goal of this paper is design of a modular, robust
and efficient operating system which provide an environment for
applications
to exploit the parallelism available in the cm* multi-processor machine.

The basic idea is to use the local resources of the each processor as
much
as possible while reducing the usage of global resources. Each processor

in this cm* machine provide small functionality and in combination of
all
processors provide total functionality of the operating system. Whenever

a functionality that is not available on the local machine the control
is transferred to the process which has that functionality instead of
accessing
that functionality through the global memory. This control of transfer
is
achieved by sending a message to the destination processor. Modularity
is
achieved by separating the well defined functionality. Some form of
reliability
is achieved by selectively replicating the functionality provided by
each
processor. The each functionality is called as utility. The UDL provide
an indirection in addressing the provider of the utility there by
location
independence of utility is achieved and also provide mechanism for
replicating an utility under the heavy load. Another design aspect of
this operating
is to provide support of exception mechanism. The load balancing
mechanisms are dynamic but it is very hard to measure under what
circumstance the load balancing activities are triggered.

--
Kiran Tati (Graduate Student)            Kiran Tati
UCSD/CSE AP&M 4402                       9450 Gilman Drive
9500, Gilman Drive, Dept. 0114           UCSD#922563
La Jolla, CA, 92093-0114                 La Jolla, CA 92092-2563
Phone:  858 5345486 (Office)             858 552 9291 (Home)
E-Mail: ktati@csag.ucsd.edu

Office Address: AP & M 6426