Re: [ANNOUNCE] Adeos nanokernel for Linux kernel

[Peter Wächtler]

Daniel Phillips wrote:
> On Tuesday 04 June 2002 21:29, Oliver Xymoron wrote:
> 
>>On Mon, 3 Jun 2002, Daniel Phillips wrote:
>>
>>
>>>traditional IT.  Not to mention that I can look forward to a sound
>>>system where I can be *sure* my mp3s won't skip.
>>>
>>Not unless you're loading your entire MP3 into memory, mlocking it down,
>>and handing it off to a hard RT process. And then your control of the
>>playback of said song through a non-RT GUI could be arbitrarily coarse,
>>depending on load.
>>
> 
> Thanks for biting :-)
> 
> First, these days it's no big deal to load an entire mp3 into memory.  
> 
> Second, and of more interest to broadcasting industry professionals and the 
> like, it's possible to write a real-time filesystem that bypasses all the 
> normal non-realtime facilities of the operating system, and where the latency 
> of every operation is bounded according to the amount of data transferred.  
> Such a filesystem could use its own dedicated disk, or, more practically, the 
> RTOS (or realtime subsystem) could operate the disk's block queue.
> 
> If I recall correctly, XFS makes an attempt to provide such realtime 
> guarantees, or at least the Solaris version does.  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.
> 
> 

It's XFS with a realtime volume under Irix.
With the React extension Irix is also capable of "hard realtime".
But these days the term realtime is a lot misused - and leeds to
assumption of a better "system".