Messages in this thread | | | Date | Wed, 21 Jul 1999 22:04:35 +0200 | From | Kurt Garloff <> | Subject | Re: [OFFTOPIC] Is Linux a Realtime-os? |
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On Wed, Jul 21, 1999 at 08:55:50PM +0200, Johan Andersson wrote: > > Well, this is VERY offtopic, but i wonder: > Is Linux a real-time os just like Qnx? > I have read it somewere, but i cant remember were, and now me and my > friends talked about it, but we found no answer. > > And, if linux now is a realtime-os, how can you see that if you compare to > other os that not is realtime.
No. Note that the features needed for (hard) RT and the ones needed for a general prupose time-sharing OS can not be fulfilled at the same time. Linux does not try to be a hard RT OS. A hard RT OS has to guarantee some _maximum_ latencies (for event processing, interrupts, scheduling, ...), which Linux can't. You may have a look a RT-Linux which targets to be a hard RT OS and has gone quite far that way ...
However, there is also something called soft RT (POSIX) which can't guarantee anything but provides means to tweak the scheduler amongst other things. Soft RT performance can be measured in terms of _average_ latencies and Linux is not that bad in this area.
Regards, -- Kurt Garloff <garloff@suse.de> SuSE GmbH, Nürnberg, FRG Linux kernel development; SCSI drivers: tmscsim(DC390), DC395 [unhandled content-type:application/pgp-signature] | |