[time-nuts] FreeBSD, NetBSD, or Minix-III?

M. Warner Losh imp at bsdimp.com
Sat May 16 18:25:29 UTC 2009


In message: <bf689bbe0905160731he199751t1b9212a526ea2346 at mail.gmail.com>
            Bob Paddock <bob.paddock at gmail.com> writes:
: On Sat, May 16, 2009 at 9:21 AM, Chuck Harris <cfharris at erols.com> wrote:
: > Bob Paddock wrote:
: >
: >> Anyone ever look at Minix-III (Minix-I was the progenitor to Linux)?
: >> Seems like it would be easy to make a decent time server, on
: >> embedded hardware with it.  Past iterations of the Minix-III website
: >> gave a "watch" as an example small embedded system it was meant to
: >> power.
: 
: > Why do you think Minix-III would be a good candidate for a time server?
: 
: Minix-III is based on the microkernel approach of keeping things small and fast.
: Take a look at the web site.  http://www.minix3.org/

Right.  But microkernels add latency to the dispatching of events.
And the latency tends to be variable in a typical microkernel.
Variable latency degrades performance.  I've not measured minix3, so I
don't know if it suffers from this problem or not.  Even in a
monolithic kernel you have issues with as well, since interrupts can
be masked from time to time...

Warner



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