[TUHS] STREAMS performance

[Paul Ruizendaal <pnr@planet.nl>]

> Date: Sat, 11 Apr 2020 08:44:28 -0700
> From: Larry McVoy
> 
> On Sat, Apr 11, 2020 at 11:38:44AM -0400, Norman Wilson wrote:
>> -- Stream I/O system added; all communication-device
>> drivers (serial ports, Ethernet, Datakit) changed to
>> work with streams.  Pipes were streams.
> 
> How was performance?  Was this Dennis' streams, not Sys V STREAMS?

It was streams, not STREAMS.

> I ported Lachmans/Convergents STREAMS based TCP/IP stack to the
> ETA 10 Unix and SCO Unix and performance just sucked.  Ditto for
> the Solaris port (which I did not do, I don't think it made any
> difference who did the port though).

STREAMS are outside the limited scope I try to restrain myself to, but I’m intrigued.

What in the above case drove/caused the poor performance?

There was a debate on the LKML in the late 1990’s where Caldera wanted STREAMS support in Linux and to the extent the arguments were technical *), my understanding of them is that the main show stopper was that STREAMS would make ‘zero copy’ networking impossible. If so, then it is a comment more about the underlying buffer strategy than STREAMS itself.

Did STREAMS also perform poorly in the 1986 context they were developed in?

Paul

*) Other arguments pro- and con included forward maintenance and market need, but I’m not so interested in those aspects of the debate.