From: slos <new.stephane.los@gmail.com>
Subject: Re: Ada and linux real time
Date: Wed, 7 Mar 2012 04:10:14 -0800 (PST)
Date: 2012-03-07T04:10:14-08:00 [thread overview]
Message-ID: <3a01f684-b544-4051-985d-58aab98e832c@v2g2000vbx.googlegroups.com> (raw)
In-Reply-To: 8kb66jddm0qb.1piup0wfaho1$.dlg@40tude.net
On 7 mar, 09:23, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
wrote:
> On Tue, 6 Mar 2012 13:19:24 -0800 (PST), slos wrote:
> > I have tried some code on both RT and non RT kernels but was not
> > impressed by the difference.
>
> What kind of difference you expected to see?
>
> --
> Regards,
> Dmitry A. Kazakovhttp://www.dmitry-kazakov.de
I can't post the code from the place I am, so I will just describe it.
My little test schedules a periodic task with a period of let's say
10ms.
The periodic task then calls the Ada.Real_Time.Clock and measures the
difference to the scheduled time.
The difference is stored in an array of durations where each index
correspond to an interval.
Difference < 0.1 * period
Difference < 0.2 * period
Difference < 0.5 * period
Difference < 1.0 * period
etc...
The purpose is to characterise the scheduling.
Running the program for a while I get an image of how it behaves.
Using both RT and non RT kernels give about same finding.
Thousands are correct while some are clearly out of specified period.
And I have not put any load on the system yet.
I plan to use tools provided by OSADL to stress the system but of
course it means nothing if I need some real time Ada runtime to
achieve real time performance and can't get it for free.
BR
Stéphane
next prev parent reply other threads:[~2012-03-07 12:10 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-06 21:19 Ada and linux real time slos
2012-03-07 8:23 ` Dmitry A. Kazakov
2012-03-07 12:10 ` slos [this message]
2012-03-07 14:18 ` Dmitry A. Kazakov
2012-03-08 2:38 ` Eilie
2012-03-08 8:27 ` Dmitry A. Kazakov
2012-03-08 12:04 ` Simon Clubley
2012-03-08 21:45 ` slos
2012-03-15 2:35 ` BrianG
2012-03-16 20:36 ` slos
2012-03-17 12:34 ` Simon Wright
2012-03-17 15:50 ` Simon Wright
2012-03-18 22:03 ` slos
2012-03-19 11:29 ` Georg Bauhaus
2012-03-19 13:01 ` Simon Wright
2012-03-19 13:12 ` slos
2012-03-19 13:30 ` slos
2012-03-19 13:35 ` Dmitry A. Kazakov
2012-03-19 16:11 ` slos
2012-03-19 17:55 ` Dmitry A. Kazakov
2012-03-19 22:20 ` slos
2012-03-20 8:04 ` Dmitry A. Kazakov
2012-03-19 13:20 ` Dmitry A. Kazakov
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