From: Peter Zijlstra <peterz@infradead.org>
To: Chris Friesen <cfriesen@nortel.com>
Cc: Michael Trimarchi <trimarchi@gandalf.sssup.it>,
sat <takeuchi_satoru@jp.fujitsu.com>,
lkml <linux-kernel@vger.kernel.org>,
Con Kolivas <kernel@kolivas.org>, Ingo Molnar <mingo@elte.hu>,
Raistlin <raistlin@linux.it>
Subject: Re: massive_intr on CFS, BFS, and EDF
Date: Sat, 26 Sep 2009 00:37:38 +0200 [thread overview]
Message-ID: <1253918258.18939.192.camel@laptop> (raw)
In-Reply-To: <4ABD36CE.3080400@nortel.com>
On Fri, 2009-09-25 at 15:31 -0600, Chris Friesen wrote:
> On 09/25/2009 10:07 AM, Michael Trimarchi wrote:
> > It is important to note that
> > the expected behavior of an edf scheduler is *not* a fair one. It has to
> > do its best to guarantee the deadlines of the admitted tasks.
>
> Do you allow oversubscription with EDF? It would seem so based on these
> results. Would it maybe make sense to disallow oversubscription, or
> make it an option?
afaiu he doesn't, he simply splits the task's wcet between parent and
child and (intends?) to feed back on child exit.
> If you have massive oversubscription with EDF, what is the design
> intent? Do you try to meet the goals on as many tasks as possible,
> while the oversubscribed tasks get nothing?
oversubscribing edf isn't in general recommended, iirc u>1 gives
unbounded latencies with edf.
next prev parent reply other threads:[~2009-09-25 22:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-24 23:53 massive_intr on CFS, BFS, and EDF sat
2009-09-25 3:27 ` Satoru Takeuchi
2009-09-25 5:35 ` Raistlin
2009-09-25 5:35 ` Raistlin
2009-09-25 16:07 ` Michael Trimarchi
2009-09-25 21:31 ` Chris Friesen
2009-09-25 22:37 ` Peter Zijlstra [this message]
2009-09-25 22:46 ` Chris Friesen
2009-09-26 7:22 ` Raistlin
2009-09-26 6:56 ` Raistlin
2009-09-26 6:50 ` Raistlin
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