Re: [2.4.17/18pre] VM and swap - it's really unusable

[Rick Stevens]

Daniel Phillips wrote:

> On January 14, 2002 10:09 am, [e-mail] wrote:
> 
>>UNIX generally tries to ensure liveness. So you know that
>>	cat lkarchive | grep feel | wc
>>will complete and not just that, it will run pretty reasonably because
>>for UNIX _every_ process is important and gets cpu and IO time.
>>When you start trying to add special low latency tasks, you endanger
>>liveness.  And preempt is especially corrosive because one of the 
>>mechanisms UNIX uses to assure liveness is to make sure that once a 
>>process starts it can do a significant chunk of work.
>>
> 
> You're claiming that preemption by nature is not Unix-like?

Unix started out life as a _time-sharing_ OS.  It never claimed to
be preemptive or real time.  For those, you waited a while, then
got to run MACH.
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- Rick Stevens, SSE, VitalStream, Inc.      [e-mail] -
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