[f2f]

If by "cpu server allocator" you mean cluster/distributed scheduler, no there's no such thing. late in the life of plan9 an attempt was made to craft something like that on top of it but by then both BL and the public had passed on the system. You have to remember that "cluster" as a term postdates this talk. A network in the view of Plan 9's creators in 1990 was composed of heterogeneous hardware and you made the choice beforehand whether you wanted to run on the big multicore system, the one with the faster I/O, or the one that displayed graphics. a homogenous entity of cheap COTS systems where everything looked the same and you made the choice where to run based on availability took another decade to materialize.

Plan 9 did implement lightweight processes by the time it was open sourced in 2000 using coroutines (http://man.cat-v.org/plan_9/2/thread) which were a C port of the primitives used in the Alef programming language, which never made it to open source land. Alef appeared in 1992.

[leoc]

Probably should mention Inferno https://en.wikipedia.org/wiki/Inferno_(operating_system) too, though afaik it doesn't have any kind of automatic distributed execution either.