Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751420AbZIHOlG (ORCPT ); Tue, 8 Sep 2009 10:41:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751326AbZIHOlF (ORCPT ); Tue, 8 Sep 2009 10:41:05 -0400 Received: from mail-px0-f184.google.com ([209.85.216.184]:59374 "EHLO mail-px0-f184.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176AbZIHOlE (ORCPT ); Tue, 8 Sep 2009 10:41:04 -0400 Subject: Re: question on sched-rt group allocation cap: sched_rt_runtime_us Mime-Version: 1.0 (Apple Message framework v1075.2) Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes From: Anirban Sinha In-Reply-To: <1252399347.7746.19.camel@twins> Date: Tue, 8 Sep 2009 07:41:01 -0700 Cc: Anirban Sinha , Mike Galbraith , linux-kernel@vger.kernel.org, Ingo Molnar , Dario Faggioli Content-Transfer-Encoding: 7bit Message-Id: <729B1E67-339D-405E-A07D-80C8275B55FF@anirban.org> References: <36bbf267-be27-4c9e-b782-91ed32a1dfe9@g1g2000pra.googlegroups.com> <1252218779.6126.17.camel@marge.simson.net> <1252310374.7564.6.camel@twins> <9039A647-41AF-43C0-9376-F21E664F61E5@anirban.org> <1252399347.7746.19.camel@twins> To: Peter Zijlstra X-Mailer: Apple Mail (2.1075.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1517 Lines: 58 On 2009-09-08, at 1:42 AM, Peter Zijlstra wrote: > On Tue, 2009-09-08 at 00:08 -0700, Anirban Sinha wrote: > >>> Actually there is, use cpusets to carve the system into partitions. >> >> hmm. ok. I looked at the code a little bit. It seems to me that the >> 'borrowing' of RT runtimes occurs only from rt runqueues belonging to >> the same root domain. And partition_sched_domains() is the only >> external interface that can be used to create root domain out of a >> CPU >> set. But then I think it needs to have CGROUPS/USER groups enabled? >> Right? > > No you need cpusets, you create a partition by disabling load- > balancing > on the top set, thereby only allowing load-balancing withing the > children. > Ah I see. Thanks for the clarification. > The runtime sharing is a form of load-balancing. sure. > > CONFIG_CPUSETS=y Hmm. Ok. I guess what I meant but did not articulate properly (because I was thinking in terms of code) was CPUSETS needed CGROUPS support: config CPUSETS bool "Cpuset support" depends on CGROUPS Anyway, that's fine. I'll dig around the code a little bit more. > > Documentation/cgroups/cpusets.txt Thanks for the pointer. My bad, I did not care to see the docs. I tend to ignore docs and read code instead. :D > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/