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Date: Sat, 20 Jun 2015 21:55:05 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: Dieter BSD <dieterbsd@gmail.com>
Cc: freebsd-hackers@freebsd.org
Subject: Re: Realtime process CPU starvation
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On Fri, Jun 19, 2015 at 05:10:11PM -0700, Dieter BSD wrote:

> Chris typed:
> > I have a process running at realtime priority 0
> > under FreeBSD 10.0. The main thread needs to run every 10 ms,
> 
> #include <standard_useless_response.h>
> FreeBSD is not a true real time OS.  Please submit your patch
> to make it one.

For make it one first need develop and enforce some policy for drivers
and programs. For exmample, RT-11 declare "A good guideline is to
spend no more than 50 microseconds at priority 7".

Also, need new disk i/o subsystem, for try async disk i/o (currently
disk i/o is synchronys for many operations like open, close, rename,
mkdir, delete) and allowing abort and cancel all i/o operations.