Re: [PATCH 01/13] sched: Add 3 new scheduler syscalls to support an extended scheduling parameters ABI

From: Juri Lelli <juri.lelli@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>,
	Dario Faggioli <raistlin@linux.it>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Oleg Nesterov <oleg@redhat.com>,
	fweisbec@gmail.com, darren@dvhart.com, johan.eker@ericsson.com,
	p.faure@akatech.ch, Linux Kernel <linux-kernel@vger.kernel.org>,
	claudio@evidence.eu.com, michael@amarulasolutions.com,
	fchecconi@gmail.com, tommaso.cucinotta@sssup.it,
	nicola.manica@disi.unitn.it, luca.abeni@unitn.it,
	dhaval.giani@gmail.com, hgu1972@gmail.com,
	Paul McKenney <paulmck@linux.vnet.ibm.com>,
	insop.song@gmail.com, liming.wang@windriver.com,
	jkacur@redhat.com
Subject: Re: [PATCH 01/13] sched: Add 3 new scheduler syscalls to support an extended scheduling parameters ABI
Date: Tue, 21 Jan 2014 17:46:13 +0100	[thread overview]
Message-ID: <52DEA455.7000208@gmail.com> (raw)
In-Reply-To: <20140121160647.GD31570@twins.programming.kicks-ass.net>

On 01/21/2014 05:06 PM, Peter Zijlstra wrote:
> On Tue, Jan 21, 2014 at 11:02:55AM -0500, Steven Rostedt wrote:
>> On Tue, 21 Jan 2014 16:46:03 +0100
>> Peter Zijlstra <peterz@infradead.org> wrote:
>>
>>> On Tue, Jan 21, 2014 at 04:38:51PM +0100, Peter Zijlstra wrote:
>>>>     SCHED_DEADLINE: Sporadic task model deadline scheduling
>>>> 	SCHED_DEADLINE is an implementation of GEDF (Global Earliest
>>>> 	Deadline First) with additional CBS (Constant Bandwidth Server).
>>>
>>> We might want to re-word that to:
>>>
>>> 	SCHED_DEADLINE currently is an implementation of GEDF, however
>>> 	any policy that correctly schedules the sporadic task model is
>>> 	a valid implementation.
>>>
>>> To make sure we should not rely on the actual implementation; there's
>>> many possible algorithms to schedule the sporadic task model.
>>
>> Probably should post some links to GEDF documentation too?
> 
> At best I think we can do something like:
> 
> SEE ALSO
> 	Documentation/scheduler/sched_deadline.txt in the Linux kernel
> 	source tree (since kernel 3.14).
> 
> Possibly also an ISBN for a good scheduling theory book (if there exists
> such a thing), but I would have to rely on others to provide such as my
> shelfs are devoid of such material.
> 

Well, picking just one is not that easy, I'd say (among many others):

 - Handbook of Scheduling: Algorithms, Models, and Performance Analysis
   by Joseph Y-T. Leung, James H. Anderson - ISBN-10: 1584883979
   (especially cap. 30);
 - Hard Real-Time Computing Systems by Giorgio C. Buttazzo
   ISBN 978-1-4614-0675-4 (even if it is more about UP);
 - A survey of hard real-time scheduling for multiprocessor systems
   by RI Davis, A Burns - ACM Computing Surveys (CSUR), 2011
   (available at http://www-users.cs.york.ac.uk/~robdavis/papers/MPSurveyv5.0.pdf);

Probably last one is better (as is freely downloadable). We should add
something in the documentation too.

Thanks,

- Juri