Evaluations

Yang YU (yyu@cs.ucsd.edu)
Wed, 17 May 2000 22:06:29 -0700

Lightweight Remote Procedure Call
MainPoint:
Light weighted RPC(based on RPC) designed to handle
communication between protected domains on a SINGLE machine.

Challenges:
monolithic kernels: few protection boundaries inside OS itself,
less secure, less modifiable, debuggable.
Capability systeme: fine grained objects sharing the space
address but have own protected domains. But not efficient.
How to solve the problem:
most communications are between domains on the same machine
most communications are simple.
RPC is too expensive to be used to handle local communications.
Approaches:
Lightweight RPC
Simple Control transfer
Simple data transfer
Simple stubs

Comments:
Their ideas are useful and helpful

Active Messages
Main Ponint:
Active Messages integrates computation and communication so that
the communication overhead is low while the processor performance is
good.

Design Challenge for large - scale mulitprocessors:
(1) lower communication overhead
(2) overlap computation and communication
(3) integrate the two without lost on performance

Traditional approaches:
Message Passing Architecture: more focused on processing,
results in high overhead in communication
Prototype of Message Driven Architectures: hardware resources
are mostly spent on message transmission, reception and scheduling.
Leads to short compuation lengths, which waste the processors's power.
Reasons of slowdown(overlap prevented):
(1) buffering and resource allocation
(2) blocking or delayed service is allowed

Goal of AM:
get data from network and integrate them in to computation as
soon as possible.

Approaches:
allowing sender specify the address of the handler when message
arrives.
No buffering
Deadlock avoidance
Cases:
Split-C, CM-5, nCuBe2, TAM
Comment:
I think this paper is well organized, Find the problem, solve
the problem

--
Yang Yu
Department of Computer Science and Engineering
University of California, San Diego