The fork() problem is due to memory registration aggravated by
registration cache. Memory registration in itself is a hack from
the OS
point of view, and you already know a lot about the various problems
related to registration cache.
So Gleb is indicating that this is a problem in the pipeline protocol
which does not use a registration cache. I think the registration
cache, while increasing the probability of badness after fork, is not
the culprit.
The right way to fix the fork problem is to fix the memory
registration
problem in the OS itself. It's not going to happen anytime soon, so it
requires another hack (forcing VM duplication of registered pages at
fork time).
Patrick
--
Patrick Geoffray
Myricom, Inc.
http://www.myri.com
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