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From: Raistlin <raistlin@linux.it>
To: Chris Friesen <cfriesen@nortel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	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>
Subject: Re: massive_intr on CFS, BFS, and EDF
Date: Sat, 26 Sep 2009 09:22:20 +0200	[thread overview]
Message-ID: <1253949740.4924.34.camel@Palantir> (raw)
In-Reply-To: <4ABD4839.7060508@nortel.com>

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On Fri, 2009-09-25 at 16:46 -0600, Chris Friesen wrote:
> On 09/25/2009 04:37 PM, Peter Zijlstra wrote: 
> > afaiu he doesn't, he simply splits the task's wcet between parent and
> > child and (intends?) to feed back on child exit.
> 
> How does this work if we have one parent task that forks off a bunch of
> kids like massive_intr?  Does each child get half the bandwidth of the
> previous child?
> 
Yes, that's exactly how I think it goes... Moreover, also the parent's
bandwidth is halved at each fork, which make things very odd in
workloads like massive_intr! :-(

> Right...so would it perhaps be more interesting to try a modified test
> where each child's bandwidth is equal and small enough that there is no
> oversubscription?
> 
So right! I think that should be the way to go, and I'll try to do
something like this as soon as I can... I promise... :-D

Regards,
Dario

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
----------------------------------------------------------------------
Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa  (Italy)

http://blog.linux.it/raistlin / raistlin@ekiga.net /
dario.faggioli@jabber.org

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  reply	other threads:[~2009-09-26  7:22 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
2009-09-25 22:46       ` Chris Friesen
2009-09-26  7:22         ` Raistlin [this message]
2009-09-26  6:56       ` Raistlin
2009-09-26  6:50     ` Raistlin

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