From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Sat, 20 Dec 2014 17:04:08 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Message-ID: <20141220160408.GB3961@daedalus>
References: <CAFgu5KXBDRLxt4q3PUw9he+4Z97RV0=Q96Y+or7FzEwT3CVZRA@mail.gmail.com>
 <20141220153337.GD24110@csclub.uwaterloo.ca>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20141220153337.GD24110@csclub.uwaterloo.ca>
Subject: Re: [Xenomai] Kernel Configuration Woes
List-Id: Discussions about the Xenomai project <xenomai.xenomai.org>
List-Unsubscribe: <http://www.xenomai.org/mailman/options/xenomai>,
 <mailto:xenomai-request@xenomai.org?subject=unsubscribe>
List-Archive: <http://www.xenomai.org/pipermail/xenomai/>
List-Post: <mailto:xenomai@xenomai.org>
List-Help: <mailto:xenomai-request@xenomai.org?subject=help>
List-Subscribe: <http://www.xenomai.org/mailman/listinfo/xenomai>,
 <mailto:xenomai-request@xenomai.org?subject=subscribe>
To: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Cc: xenomai@xenomai.org

On Sat, Dec 20, 2014 at 10:33:37AM -0500, Lennart Sorensen wrote:
> On Sat, Dec 20, 2014 at 12:05:25AM -0800, Justin Hart wrote:
> > I recently rebuilt my kernel and I seem to be running into some problems
> > that I previously encountered with xenomai.  Unforutnately, I can't seem to
> > fix them.
> > 
> > When I load my application (which runs at Barrett WAM), I get the following
> > messages in my kernel log.
> > 
> > Dec 19 23:59:01 magnum kernel: [ 1232.835449] Clocksource tsc unstable
> > (delta = 1998076024 ns)
> > Dec 19 23:59:01 magnum kernel: [ 1232.835477] Switched to clocksource
> > refined-jiffies
> > 
> > At this juncture, a few things happen, my entire system grinds to a halt,
> > my system clock starts to drift significantly, and xeno-test reports major
> > clock drift.
> > 
> > CPU  ToD offset [us] ToD drift [us/s]      warps max delta [us]
> > --- -------------------- ---------------- ---------- --------------
> >   0          164328553.0      7034205.095          0            0.0
> >   1          164329131.5      7033385.416          0            0.0
> >   2          164328794.0      7030756.296          0            0.0
> >   3          164328783.3      7030646.980          0            0.0
> > 
> > I'm running kernel 3.14.17, xenomai 2.6.4, and the default ipipe that comes
> > with 2.6.4
> > 
> > Attached is my .config
> > 
> > Does anybody have any idea what I'm doing wrong?  This looks pretty close
> > to what I had marked in my notes.
> 
> I suspect it would help a lot to know what hardware this is on.
> 
> The tsc being unstable seems rather bad, since I can't imagine using
> jiffies is going to give any removely stable for system time.
> 
> I am surprised if any modern x86 hardware has bad tsc support, unless
> of course SMI is involved.

To make it simple: from Linux point of view, Xenomai behaves just as
an SMI.

-- 
					    Gilles.