[Info-vax] CRTL and RMS vs SSIO

[Stephen Hoffman]

On 2021-10-08 01:19:33 +0000, Lawrence D’Oliveiro said:

> On Friday, October 8, 2021 at 7:28:07 AM UTC+13, Simon Clubley wrote:
>> The same is true for VMS CLIs BTW. DCL is tightly bound into VMS in a 
>> horrible way it should not be. On Linux, both the command shell and 
>> filesystem architectures are vastly cleaner and more modular than they 
>> are on VMS.
> Fundamental difference in mindset: process creation in VMS is expensive 
> and to be avoided if possible, while on *nix systems it’s something you 
> do as naturally as breathing.

VAX-era wisdom, and which is clung on. Creating new processes on 
OpenVMS never got as light as Unix, but the overhead has become 
negligible on modern systems for all but industrial-scale 
creation-deletion.

Having looked at this back in the VAX era, the slow process creations 
our apps were incurring were arising from inefficiencies within the DCL 
spawn-related processing, and not from within the OpenVMS process 
creation overhead.

Once that was identified and the obvious work-around implemented, 
spawns were pretty speedy even VAX-era.

To Simon's comment, how DCL gets mapped into process address space is 
just ugly, too. And hard to debug.

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