[TUHS] PDP-11 legacy, C, and modern architectures

Theodore Y. Ts'o tytso at mit.edu
Fri Jun 29 00:15:38 AEST 2018

Bakul, I think you and Steve have a very particular set of programming
use cases in mind, and are then over-generalizing this to assume that
these are the only problems that matter.  It's the same mistake
Chisnall made when he assrted the parallel programming a myth that
humans writing parallel programs was "hard", and "all you needed" was
the right language.

The problem is that not all people are interested in solving problems
which are amenable to embarassingly parallel algorithms.  Not all
programmers are interested in doing matrix multiply, or writing using
the latest hyped archiecture (whether you call by the new name,
"microservices", or the older hyped name which IBM tried to promote
"Service Oriented Architecture", or SOA).

I'll note that Sun made a big bet (one of its last failed bets) on
this architecture in the form of the Niagra architecture, with a large
number of super "wimpy" cores.  It was the same basic idea --- we
can't make big fast cores (since that would lead to high ILP's,
complex register rewriting, and lead to cache-oriented security
vulnerabilities like Spectre and Meltdown) --- so instead, let's make
lots of tiny wimpy cores, and let programmers write highly threaded
programs!  They essentially made a bet on the web-based microservice
model which you are promoting.

And the Market spoke.  And shortly thereafter, Java fell under the
control of Oracle....  And Intel would proceed to further dominate the

					- Ted

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