From: Luca Abeni <lucabe72@email.it>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Raistlin <raistlin@linux.it>,
linux-kernel <linux-kernel@vger.kernel.org>,
Song Yuan <song.yuan@ericsson.com>,
Dmitry Adamushko <dmitry.adamushko@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Nicola Manica <nicola.manica@disi.unitn.it>,
Claudio Scordino <claudio@evidence.eu.com>,
Harald Gustafsson <harald.gustafsson@ericsson.com>,
Bjoern Brandenburg <bbb@email.unc.edu>,
bastoni@cs.unc.edu, Giuseppe Lipari <lipari@retis.sssup.it>
Subject: Re: periods and deadlines in SCHED_DEADLINE
Date: Sat, 10 Jul 2010 09:11:47 +0200 [thread overview]
Message-ID: <1278745907.5248.18.camel@localhost> (raw)
In-Reply-To: <1278685470.1900.206.camel@laptop>
On Fri, 2010-07-09 at 16:24 +0200, Peter Zijlstra wrote:
> On Fri, 2010-07-09 at 15:38 +0200, Raistlin wrote:
> > Basically, from the scheduling point of view, what it could happen is
> > that I'm still _NOT_ going to allow a task with runtime Q_i, deadline
> > D_i and period P_i to use more bandwidth than Q_i/P_i, I'm still using D
> > for scheduling but the passing of the simple in-kernel admission test
> > Sum_i(Q_i/P_i)<1 won't guarantee that the task will always finish its
> > jobs before D.
>
> But the tardiness would still be bounded, right? So its a valid Soft-RT
> model?
I think that if Sum_i(Q_i/P_i)<1 but Sum_i(Q_i/min{P_i,D_i})>=1 then you
can have sporadic deadline misses, but it should still be possible to
compute an upper bound for the tardiness.
But this is just a feeling, I have no proof... :)
Luca
next prev parent reply other threads:[~2010-07-10 7:20 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-09 13:38 periods and deadlines in SCHED_DEADLINE Raistlin
2010-07-09 14:18 ` Peter Zijlstra
2010-07-09 14:51 ` Bjoern Brandenburg
2010-07-09 16:35 ` Peter Zijlstra
2010-07-10 9:01 ` Raistlin
2010-07-10 10:28 ` Peter Zijlstra
2010-07-10 14:49 ` Raistlin
2010-07-11 6:42 ` Bjoern Brandenburg
2010-08-03 9:41 ` Peter Zijlstra
2010-08-04 3:52 ` Andrea Bastoni
2010-08-04 7:14 ` Peter Zijlstra
2010-08-04 5:18 ` Bjoern Brandenburg
2010-08-03 9:46 ` Peter Zijlstra
2010-08-04 3:53 ` Andrea Bastoni
2010-08-04 5:02 ` Bjoern Brandenburg
2010-07-10 7:08 ` Raistlin
2010-07-11 6:46 ` Bjoern Brandenburg
2010-08-03 8:16 ` Peter Zijlstra
2010-08-03 11:42 ` Gregory Haskins
2010-08-04 6:30 ` Bjoern Brandenburg
2010-07-09 14:24 ` Peter Zijlstra
2010-07-10 7:11 ` Luca Abeni [this message]
2010-07-10 10:36 ` Peter Zijlstra
2010-07-11 6:12 ` Bjoern Brandenburg
2010-07-09 14:30 ` Peter Zijlstra
2010-07-10 9:14 ` Raistlin
2010-07-10 17:19 ` Harald Gustafsson
2010-07-10 18:31 ` Peter Zijlstra
2010-07-10 20:08 ` Harald Gustafsson
2010-07-10 21:52 ` Raistlin
2010-07-11 5:41 ` Harald Gustafsson
2010-07-11 7:32 ` Bjoern Brandenburg
2010-07-12 10:21 ` Harald Gustafsson
2010-08-04 5:55 ` Bjoern Brandenburg
2010-08-02 19:34 ` Peter Zijlstra
2010-08-04 4:44 ` Bjoern Brandenburg
2010-07-09 14:32 ` Peter Zijlstra
2010-07-10 7:50 ` Raistlin
2010-07-10 15:11 ` Peter Zijlstra
2010-07-10 17:29 ` Harald Gustafsson
2010-07-11 6:15 ` Bjoern Brandenburg
2010-07-10 7:09 ` Luca Abeni
2010-07-10 9:20 ` Raistlin
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