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From: "Måns Rullgård" <mru@mru.ath.cx>
To: linux-kernel@vger.kernel.org
Subject: Re: [ANNOUNCE] Linux 2.6 Real Time Kernel
Date: Sat, 09 Oct 2004 21:38:41 +0200	[thread overview]
Message-ID: <yw1xvfdjadha.fsf@mru.ath.cx> (raw)
In-Reply-To: 1097350227.1428.41.camel@krustophenia.net

Lee Revell <rlrevell@joe-job.com> writes:

>> > > To the best of my understanding, this still doesn't provide
>> > > deterministic hard-real-time performance in Linux.
>> > 
>> > Using only the VP+IRQ thread patch, I ran my RT app for 11 million
>> > cycles yesterday, with a maximum delay of 190 usecs.  How would this not
>> > satisfy a 200 usec hard RT constraint?
>> 
>> I think the keyword here is "deterministic", isn't it?
>
> Well, depends what you mean by deterministic.  Some RT apps only require
> an upper bound on response time.  This is a form of determinism.

Sure, but running for a zillion cycles without breaking some limit
doesn't guarantee that it never will happen.  Being able to give such
a guarantee is what determinism is about.

-- 
Måns Rullgård
mru@mru.ath.cx


  reply	other threads:[~2004-10-09 19:39 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-09  5:59 [ANNOUNCE] Linux 2.6 Real Time Kernel Sven-Thorsten Dietrich
2004-10-09  6:40 ` Lee Revell
2004-10-09  7:33   ` Daniel Walker
2004-10-09  7:42     ` Lee Revell
2004-10-09 23:40       ` Matthias Urlichs
2004-10-09  8:52     ` Lee Revell
2004-10-09 23:20     ` Dave Hansen
2004-10-09 23:24       ` Lee Revell
2004-10-09 10:51 ` Måns Rullgård
2004-10-09 13:15 ` Måns Rullgård
2004-10-09 21:20   ` Lee Revell
2004-10-09 21:35     ` Måns Rullgård
2004-10-09 21:37       ` Lee Revell
2004-10-09 21:45         ` Måns Rullgård
2004-10-09 21:55       ` Lee Revell
2004-10-09 22:21         ` Måns Rullgård
2004-10-09 23:52       ` Lee Revell
2004-10-10  0:05         ` Måns Rullgård
2004-10-10  0:45           ` Lee Revell
2004-10-10  1:05             ` Måns Rullgård
2004-10-10  1:09               ` Lee Revell
2004-10-10  0:43       ` Micha Feigin
2004-10-10  1:08         ` Måns Rullgård
2004-10-09 17:41 ` Karim Yaghmour
2004-10-09 18:30   ` Lee Revell
2004-10-09 21:26     ` stefan.eletzhofer
2004-10-09 19:30       ` Lee Revell
2004-10-09 19:38         ` Måns Rullgård [this message]
2004-10-09 21:38         ` stefan.eletzhofer
2004-10-09 19:47           ` Lee Revell
2004-10-09 20:11             ` Karim Yaghmour
2004-10-09 20:14               ` Lee Revell
2004-10-09 20:53                 ` Karim Yaghmour
2004-10-09 20:59                   ` Lee Revell
2004-10-09 20:20             ` Robert Love
2004-10-09 20:25               ` Lee Revell
2004-10-10  1:15 ` Lee Revell
2004-10-10  8:46 ` Ingo Molnar
2004-10-10 19:41   ` Daniel Walker
2004-10-10 19:46     ` Ingo Molnar
2004-10-10 21:20     ` Andrew Morton
2004-10-10 21:59       ` Ingo Molnar
2004-10-11 17:53         ` Daniel Walker
2004-10-11 20:49           ` Ingo Molnar
2004-10-11 21:44             ` Sven Dietrich
2004-10-11 21:54               ` Ingo Molnar
2004-10-11 23:05                 ` Sven Dietrich
2004-10-12  5:50                   ` Ingo Molnar
2004-10-14  5:09                     ` Dipankar Sarma
2004-10-14  7:18                       ` Ingo Molnar
2004-10-15 14:59                         ` Paul E. McKenney
2004-10-15 15:45                           ` Ingo Molnar
2004-10-15 16:40                             ` Paul E. McKenney
2004-10-15 16:45                               ` Paul E. McKenney
2004-10-17 17:12                       ` Ingo Molnar
2004-10-12 18:50             ` Daniel Walker
2004-10-12 19:46               ` [Ext-rt-dev] " Thomas Gleixner
2004-10-12 20:31                 ` Sven Dietrich
2004-10-12 20:37                   ` Thomas Gleixner
2004-10-13  0:30                   ` George Anzinger
2004-10-12 21:12                 ` Bill Huey
2004-10-12 21:24                   ` Bill Huey
2004-10-12 21:32                     ` Thomas Gleixner
2004-10-12 23:13                       ` Bill Huey
2004-10-12 21:41                   ` Sven Dietrich
2004-10-12 22:57                     ` Bill Huey
2004-10-12 23:17                       ` Adam Heath
2004-10-12 23:36                         ` Lee Revell
2004-10-12 23:25                       ` Thomas Gleixner
2004-10-13  2:02                       ` K.R. Foley
2004-10-13 13:39                       ` Martijn Sipkema
2004-10-13 13:26                         ` La Monte H.P. Yarroll
2004-10-13 15:04                           ` Martijn Sipkema
2004-10-13 14:55                             ` Kurt Wall
2004-10-13 14:52                               ` Christoph Hellwig
2004-10-13 15:56                         ` Lee Revell
2004-10-13 16:13                           ` Robert Love
2004-10-13 17:14                           ` Martijn Sipkema
2004-10-13  3:55                     ` Bill Huey
2004-10-12 22:00                   ` Thomas Gleixner
2004-10-12 22:36                     ` Bill Huey
2004-10-12 23:10                       ` Thomas Gleixner
2004-10-12 23:33                         ` Bill Huey
2004-10-12 23:37                           ` Thomas Gleixner
2004-10-12 23:52                             ` Bill Huey
2004-10-13  0:59                         ` Valdis.Kletnieks
2004-10-10 12:21 ` John Richard Moser
2004-10-10 17:26   ` Lee Revell
2004-10-10 18:45     ` John Richard Moser
2004-10-10 20:20       ` Ingo Molnar
2004-10-10 20:44         ` John Richard Moser
2004-10-10 17:29   ` Daniel Walker
  -- strict thread matches above, loose matches on Subject: below --
2004-10-09 11:38 John Hedditch
2004-10-09 22:54 Sven Dietrich
2004-10-11 15:28 Vadim Lebedev
2004-10-11 15:50 ` Eugeny S. Mints

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