We investigate here the programming effort and performance of a programming model which is a hybrid between shared memory
and messagepassing. This model permits an easy implementation in shared memory, while still being able to benefit from performance
advantages of message-passing for performance critical tasks. We have integrated message-passing with a software DSM system,
and evaluated the programming effort and performance with three different applications and various degree of messagepassing
in the applications.
In two of the applications we found that only a small fraction of the source code lines responsible for interprocess communication
were performance critical and it was therefore easy to convert only those to message-passing primitives and still approach
the performance of pure message-passing.