Re: pure C90 environment

From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.std.c
Subject	Re: pure C90 environment
Date	2020-05-18 13:23 +1200
Message-ID	<hie6c2FamcgU1@mid.individual.net> (permalink)
References	<005caece-e5a1-4376-8e05-7ed7b02afe4a@googlegroups.com> <7fc3b639-9c7b-4292-8a20-d98dde05e4a8@googlegroups.com> <ec171ebd-e9b3-44a9-988a-8c4a7685e58e@googlegroups.com> <9c0facf4-9e33-4c6e-8692-773f49114a96@googlegroups.com>

Show all headers | View raw

On 18/05/2020 08:02, Malcolm McLean wrote:
> On Sunday, 17 May 2020 13:41:30 UTC+1, Paul Edwards  wrote:
>> On Wednesday, 13 May 2020 20:02:09 UTC+10, Malcolm McLean  wrote:
>>
>>> I'm reviving this. I think yur niche might be virtual machines.
>>> A virtual machine needs to be able to run with constrained resources
>>> and an OS that keeps out of the way. We know it is possible to do
>>> serious work with only a few MB of RAM and and few tens of MB hard drive
>>> space, because for many years PCs had that specification.
>>>
>>> That's nothing for a modern PC. A virutal machine could be a faitly
>>> lightweight application in the host environment.
>>
>> Can you elaborate on this please? Which OS
>> needs to keep out of the way? Would that be
>> PDOS/386? Which currently allows applications
>> to directly manipulate I/O ports.
>>
> Virtual machines are usually hosted on a fully-featured, modern OS like
> Windows or Apple;s OSX, running on a desktop machine with several
> gigabytes of memory and several hundred gigabytes of backing store.
> The virtual machine itself is just an ordinary application, running
> under the host OS.

One class of VM meets that description but not all.

> However there's a real need for virtual machines to be light on resources.

The need is already met.  Solaris derived platforms have has lightweight 
zones since the early 2000s.  Linux now has containers.

> Their memory and disk space is memory and disk space that cannot be used
> by the host machine. So the OS on the virtual machine needs to keep out of
> the way. It can't be hogging huge tracts of memory or hard disk space.

Zones and containers share resources with the host OS.

> However, whilst Linux is
> acceptable for virtual machines, a typical Linux installation is
> still rather greedy. 

BusyBox

-- 
Ian.

Back to comp.std.c | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: pure C90 environment Ian Collins <ian-news@hotmail.com> - 2020-05-18 13:23 +1200
  Re: pure C90 environment Ian Collins <ian-news@hotmail.com> - 2020-05-18 13:26 +1200

csiph-web