All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jeff Angielski <jeff@theptrgroup.com>
To: Robert Schwebel <r.schwebel@pengutronix.de>
Cc: Raz <raziebe@gmail.com>,
	"Nikita V. Youshchenko" <yoush@cs.msu.su>,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Subject: Re: preempt rt in commercial use
Date: Tue, 14 Sep 2010 10:21:52 -0400	[thread overview]
Message-ID: <4C8F8500.5070002@theptrgroup.com> (raw)
In-Reply-To: <20100914094411.GB10841@pengutronix.de>

On 09/14/2010 05:44 AM, Robert Schwebel wrote:
> On Tue, Sep 14, 2010 at 11:24:21AM +0200, Raz wrote:
>> anyone can say preempt rt is hard real time?
>
> Hard realtime has something to do with how you define "missing the
> deadline". If somebody cuts the cable of your roboter controller in the
> factory hall, the system misses the deadline. So it is all about
> probabilities: hard realtime systems have a very, very low probability
> of missing the deadline. However, in real life systems, it is>  0%.
>
> So yes, if you talk about real world, it is hard realtime.

No.  Preempt rt it's not hard realtime.

But most people/companies who think they need hard realtime really 
don't.  They can live with soft realtime and have a really low 
probability of missing deadlines and having long latencies.  For these 
people, the preempt rt is adequate.

-- 
Jeff Angielski
The PTR Group
www.theptrgroup.com

  parent reply	other threads:[~2010-09-14 14:32 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-14  8:10 preempt rt in commercial use Raz
2010-09-14  9:04 ` Rolando Martins
2010-09-14  9:10   ` Raz
2010-09-14  9:20     ` Rolando Martins
2010-09-14  9:17 ` Nikita V. Youshchenko
2010-09-14  9:24   ` Raz
2010-09-14  9:44     ` Robert Schwebel
2010-09-14 12:16       ` Armin Steinhoff
2010-09-14 13:04         ` Daniel James
2010-09-14 13:08         ` Pradyumna Sampath
2010-09-14 22:11           ` Nivedita Singhvi
2010-09-14 13:09         ` Klaas van Gend
2010-09-14 13:17         ` David Kastrup
2010-09-14 13:37           ` Darcy Watkins
2010-09-14 13:58         ` Patrice Kadionik
2010-09-14 14:21       ` Jeff Angielski [this message]
2010-09-14 14:30         ` Nikita V. Youshchenko
2010-09-14 14:49           ` Jeff Angielski
2010-09-14 22:20             ` Nivedita Singhvi
2010-09-15  7:48               ` Armin Steinhoff
2010-09-15 14:09                 ` Nivedita Singhvi
2010-09-15 14:45                   ` Pradyumna Sampath
2010-09-16 10:17                     ` Daniel James
2010-09-16 10:35                       ` Pradyumna Sampath
2010-09-16 15:19                       ` Raz
2010-09-15 15:38                   ` David Kastrup
2010-09-15 16:02                     ` Nivedita Singhvi
2010-09-15 16:20                       ` David Kastrup
2010-09-16  0:44                         ` Steven Rostedt
2010-09-16 15:27                           ` Nivedita Singhvi
2010-09-16 17:30                             ` Steven Rostedt
2010-09-16 19:27                               ` Armin Steinhoff
2010-09-16 19:38                                 ` Steven Rostedt
2010-09-15 13:33             ` Thomas Gleixner
2010-09-14 14:44         ` Pradyumna Sampath
2010-09-15 12:48           ` Sergio Ruocco
2010-09-15 12:53             ` Pradyumna Sampath
2010-09-15 14:58             ` Paul E. McKenney
2010-09-15 16:27             ` Sven-Thorsten Dietrich
2010-09-16  0:49               ` Steven Rostedt
2010-09-16  5:06                 ` David Kastrup
2010-09-14 14:56         ` Armin Steinhoff
2010-09-14 15:42         ` Patrice Kadionik
2010-09-14 17:38         ` Gregory Haskins
2010-09-14 22:09           ` Nivedita Singhvi
2010-09-15  6:22             ` Patrice Kadionik
     [not found]               ` <4C90CF71.2050205@us.ibm.com>
2010-09-15 13:56                 ` Patrice Kadionik
2010-09-15 14:08               ` Steven Rostedt
2010-09-14 10:06   ` Klaas van Gend
2010-09-14 11:00     ` David Kastrup
2010-09-14  9:28 ` Pradyumna Sampath
2010-09-14 14:13 ` Reagan Thomas
2010-09-15  7:09   ` AW: " Lukas Redlinger
2010-09-15  3:38 ` jordan
2010-09-15  8:59   ` Klaas van Gend
2010-09-15 11:03     ` TinxCore and PREEMPT_RT Armin Steinhoff
2010-09-16  9:38       ` Armin Steinhoff
2010-09-16 10:18         ` David Kastrup
2010-09-16 11:25           ` Mike Galbraith
2010-09-16 11:51           ` Armin Steinhoff
2010-09-15 14:03     ` preempt rt in commercial use Nivedita Singhvi
2010-09-15 17:29       ` Reagan Thomas
2010-09-16 10:39         ` Daniel James
2010-09-16 20:47           ` jordan
2010-09-16 10:07   ` Daniel James
2010-09-16 20:37     ` jordan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4C8F8500.5070002@theptrgroup.com \
    --to=jeff@theptrgroup.com \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=r.schwebel@pengutronix.de \
    --cc=raziebe@gmail.com \
    --cc=yoush@cs.msu.su \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.