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From: "Chris Friesen" <cfriesen@nortel.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>,
	bharata@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] sched: Don't allow priority switch to realtime when the task doesn't belong to init_task_group and when CONFIG_RT_GROUP_SCHED isn't set
Date: Mon, 24 Nov 2008 09:24:05 -0600	[thread overview]
Message-ID: <492AC715.9080602@nortel.com> (raw)
In-Reply-To: <1227517575.7685.21906.camel@twins>

Peter Zijlstra wrote:
> On Mon, 2008-11-24 at 14:16 +0530, Dhaval Giani wrote:
> 
> 
>>Which would mean the init_task_group becase it contains those tasks which are
>>not grouped.
> 
> 
> Only because of implementation details (we implement the !group case by
> having them all part of a single group), conceptually they don't belong
> to any group, hence talking about moving it to some group is just wrong.

> Furthermore your statement shows another misconception, a group of
> ungrouped tasks doesn't make sense.

Arguably there is such a group, which is "the set of all RT tasks".

Whether or not they should map to the top-level cgroup is a different 
question.  Maybe in the !group case there should be a second top-level 
"rt" cgroup?  We could even make the RT sched tuning knobs available there.

Chris


  reply	other threads:[~2008-11-24 15:24 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-20  6:18 [PATCH] sched: Don't allow priority switch to realtime when the task doesn't belong to init_task_group and when CONFIG_RT_GROUP_SCHED isn't set Bharata B Rao
2008-11-20  7:58 ` Ingo Molnar
2008-11-20  8:03   ` Dhaval Giani
2008-11-20  8:17     ` Ingo Molnar
2008-11-20  8:19   ` Bharata B Rao
2008-11-23  1:11 ` Peter Zijlstra
2008-11-24  3:58   ` Bharata B Rao
2008-11-24  8:32     ` Peter Zijlstra
2008-11-24  8:46       ` Dhaval Giani
2008-11-24  9:06         ` Peter Zijlstra
2008-11-24 15:24           ` Chris Friesen [this message]
2008-11-24 15:36             ` Peter Zijlstra
2008-11-25 18:51               ` Chris Friesen
2008-11-25 20:17                 ` Peter Zijlstra
2008-11-24 17:05       ` Srivatsa Vaddagiri
2008-11-24 18:46         ` Peter Zijlstra

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