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From: Bernhard Schiffner <bernhard@schiffner-limbach.de>
To: linux-rt-users@vger.kernel.org
Subject: Re: Measuring scheduling latency for RT threads
Date: Wed, 19 Nov 2014 14:11:37 +0100	[thread overview]
Message-ID: <9785835.e6QRrDJeRk@bs8> (raw)
In-Reply-To: <trinity-4b6e4283-c92f-4553-af86-5fb9e1fb1541-1416401016597@3capp-gmx-bs35>

Am Mittwoch, 19. November 2014, 13:43:36 schrieben Sie:
> I have a complex automation project with makes heavy use of real time prio
> threads working with external hardware connected by e.g. TCP/IP. IMHO most
> of my latencies simply come from the fact that there are multiple threads
> running on the same RT prio being scheduled FIFO. (poor design, yes, but
> that's what I want to fix) Expected response time is in low millsecond
> area, so no miroseconds juggling here. The process is running (alone, no
> other processes there) on one CPU of an i5 quad core (using 3.13.0-35
> ubuntu 14.04)

The expected behavior is "in general" only achiveable with patched kernels. 
The RT-patches are available here:
https://www.kernel.org/pub/linux/kernel/projects/rt/
(Notice availability only for even kernel numbers.)

So please get first of all a kernel working suited for "real realtime". This 
step should be quite simple :-)

Good luck!


Bernhard


  reply	other threads:[~2014-11-19 13:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-19 12:43 Measuring scheduling latency for RT threads "Jürgen Lanner"
2014-11-19 13:11 ` Bernhard Schiffner [this message]
2014-11-19 13:19 ` Stanislav Meduna
2014-11-19 17:59   ` Clark Williams

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