Re: [ANNOUNCE] Adeos nanokernel for Linux kernel

[Peter Wächtler]

Daniel Phillips wrote:
> On Wednesday 05 June 2002 05:56, J Sloan wrote:
> 
>>Daniel Phillips wrote:
>>
>>
>>>If I recall correctly, XFS makes an attempt to provide such realtime 
>>>guarantees, or at least the Solaris version does. 
>>>
>>>
>>When did Solaris ever support xfs?
>>
>>
>>>However, the operating 
>>>system must be able to provide true realtime guarantees in order for the 
>>>filesystem to provide them, and I doubt that the combination of XFS and 
>>>Solaris can do that.
>>>
>>>
>>no, but the combination of xfs and irix has
>>
>                                      ^^^^			
> Heh, I can only protest that Oxymoron also missed that thinko..
> 
> 
>>made a lot of folks happy -  and xfs/linux is coming along nicely as
>>well...
>>
> 
> Improving the average latency of systems is a worthy goal, and there's
> no denying that 'sorta realtime' has its place, however it's no substitute
> for the real thing.  A soft realtime system screws up only on occasion,
> but - bugs excepted - a hard realtime system *never* does.
> 

Yes, in theory. You define hard realtime system in a clean room.
Even QNX4 couldn't provide hard realtime when creating new processes.
You had to start them beforehand - so you needed good system design.
The OS is just a small part of that.

Even vxworks had problems with priority inversion ... and so on.