Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751216AbWIKIXI (ORCPT ); Mon, 11 Sep 2006 04:23:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751261AbWIKIXI (ORCPT ); Mon, 11 Sep 2006 04:23:08 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:42175 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751216AbWIKIXF (ORCPT ); Mon, 11 Sep 2006 04:23:05 -0400 Message-ID: <45051C0A.1060302@in.ibm.com> Date: Mon, 11 Sep 2006 13:49:22 +0530 From: Balbir Singh Reply-To: balbir@in.ibm.com Organization: IBM India Private Limited User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.6) Gecko/20060730 SeaMonkey/1.0.4 MIME-Version: 1.0 To: Pavel Emelianov Cc: Dave Hansen , Rik van Riel , Srivatsa , sekharan@us.ibm.com, Alan Cox , CKRM-Tech , Andi Kleen , Linux Kernel Mailing List , Christoph Hellwig , Andrey Savochkin , Matt Helsley , Hugh Dickins , Alexey Dobriyan , Kirill Korotaev , Oleg Nesterov , devel@openvz.org Subject: Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory) References: <44FD918A.7050501@sw.ru> <44FDAB81.5050608@in.ibm.com> <44FEC7E4.7030708@sw.ru> <44FF1EE4.3060005@in.ibm.com> <1157580371.31893.36.camel@linuxchandra> <45011CAC.2040502@openvz.org> <1157730221.26324.52.camel@localhost.localdomain> <4501B5F0.9050802@in.ibm.com> <450508BB.7020609@openvz.org> <4505161E.1040401@in.ibm.com> <45051AC7.2000607@openvz.org> In-Reply-To: <45051AC7.2000607@openvz.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2770 Lines: 70 Pavel Emelianov wrote: > Balbir Singh wrote: >> Pavel Emelianov wrote: >>> Balbir Singh wrote: >>>> Dave Hansen wrote: >>>>> On Fri, 2006-09-08 at 11:33 +0400, Pavel Emelianov wrote: >>>>>> I'm afraid we have different understandings of what a "guarantee" is. >>>>> It appears so. >>>>> >>>>>> Don't we? >>>>>> Guarantee may be one of >>>>>> >>>>>> 1. container will be able to touch that number of pages >>>>>> 2. container will be able to sys_mmap() that number of pages >>>>>> 3. container will not be killed unless it touches that number of >>>>>> pages >>>>> A "death sentence" guarantee? I like it. :) >>>>> >>>>>> 4. anything else >>>>>> >>>>>> Let's decide what kind of a guarantee we want. >>>> I think of guarantees w.r.t resources as the lower limit on the >>>> resource. >>>> Guarantees and limits can be thought of as the range (guarantee, limit] >>>> for the usage of the resource. >>>> >>>>> I think of it as: "I will be allowed to use this many total pages, and >>>>> they are guaranteed not to fail." (1), I think. The sum of all of >>>>> the >>>>> system's guarantees must be less than or equal to the amount of free >>>>> memory on the machine. >>>> Yes, totally agree. >>> Such a guarantee is really a limit and this limit is even harder than >>> BC's one :) >>> >>> E.g. I have a node with 1Gb of ram and 10 containers with 100Mb >>> guarantee each. >>> I want to start one more. What shall I do not to break guarantees? >> Don't start the new container or change the guarantees of the existing >> ones >> to accommodate this one :) The QoS design (done by the administrator) >> should >> take care of such use-cases. It would be perfectly ok to have a container >> that does not care about guarantees to set their guarantee to 0 and set >> their limit to the desired value. As Chandra has been stating we need two >> parameters (guarantee, limit), either can be optional, but not both. > If I set up 9 groups to have 100Mb limit then I have 100Mb assured (on > 1Gb node) > for the 10th one exactly. And I do not have to set up any guarantee as > it won't affect > anything. So what a guarantee parameter is needed for? This use case works well for providing guarantee to one container. What if I want guarantees of 100Mb and 200Mb for two containers? How do I setup the system using limits? Even I restrict everyone else to 700Mb. With this I cannot be sure that the remaining 300Mb will be distributed as 100Mb and 200Mb. -- Balbir Singh, Linux Technology Center, IBM Software Labs - 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/