Re: 3.0 wishlist Was: Overview of 2.2.x goals?

Kamran (
Thu, 22 Jan 1998 12:16:43 -0600 (CST)


Larry McVoy wrote:
>I agree with the "Linux is a widely available platform part". Scientific
>programming has moved to the MPI (message passing interface) model in a
>big way. Even on SMP machines. If anyone is serious about supporting
>scientific apps, then get an optimized version of MPI up on Linux.
>I'll bet you that the Beowolf people are working on this.

Using message passing on SMP machines with _real_ shared memory is not
very clever.

This might be the trend, but programming message passing systems is not
very easy. The main reason for their prevalence is better performace, which
is the result of transfering the needed data (and only the needed data) at
the right time to the right place.

>DIPC is cute but is likely to be ignored by the big apps.

I don't know if this will be true, but DIPC could result in a new breed of
software. Some of its advantages are:

*) Distributed shared memory is much easier to use.

*) Programs using DIPC can be run in a single computer, even on Linux
kernels without DIPC support! There is no need to modify and compile
the sources to achieve this.

*) DIPC programs can automatically use SMP hardware and real shared memory.
Again, no need for the modification and recompilation of the sources.

*) DIPC can work in heterogeneous environments (currently x86 and M68k).
This is not very common among distributed shared memory systems.

*) You don't have to learn some new programming interfaces.

*) Older programs using System V IPC can still be used.

DIPC is a very safe system to use by the programmers. They don't have to
learn a lot of new things, and their programming investment does not depend
on DIPC's success or availability. This is a very big plus.

-Kamran Karimi