From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261875AbUEEASo (ORCPT ); Tue, 4 May 2004 20:18:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261867AbUEEASo (ORCPT ); Tue, 4 May 2004 20:18:44 -0400 Received: from mtagate2.uk.ibm.com ([195.212.29.135]:24245 "EHLO mtagate2.uk.ibm.com") by vger.kernel.org with ESMTP id S261830AbUEEASj (ORCPT ); Tue, 4 May 2004 20:18:39 -0400 Message-ID: <409832D2.2020507@watson.ibm.com> Date: Tue, 04 May 2004 20:18:26 -0400 From: Shailabh Nagar User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6b) Gecko/20031205 Thunderbird/0.4 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Marcelo Tosatti CC: linux-kernel , ckrm-tech Subject: Re: [ckrm-tech] Re: [RFC] Revised CKRM release References: <4090BBF1.6080801@watson.ibm.com> <20040504173529.GE11346@logos.cnet> In-Reply-To: <20040504173529.GE11346@logos.cnet> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Marcelo Tosatti wrote: > On Thu, Apr 29, 2004 at 04:25:21AM -0400, Shailabh Nagar wrote: > >>The Class-based Resource Management project is happy to release the >>first bits of a working prototype following a major revision of its >>interface and internal organization. >> >>The basic concepts and motivation of CKRM remain the same as described >>in the overview at http://ckrm.sf.net. Privileged users can define >>classes consisting of groups of kernel objects (currently tasks and >>sockets) and specify shares for these classes. Resource controllers, >>which are independent of each other, can regulate and monitor the >>resources consumed by classes e.g the CPU controller will control the >>CPU time received by a class etc. Optional classification engines, >>implemented as kernel modules, can assist in the automatic >>classification of the kernel objects (tasks/sockets currently) into >>classes. > > > Cool! > > >>New in this release are the following: >> >>rbce.ckrm-E12: >> >>Two classification engines (CE) to assist in automatic classification >>of tasks and sockets. The first one, rbce, implements a rule-based >>classification engine which is generic enough for most users. The >>second, called crbce, is a variant of rbce which additionally provides >>information on significant kernel events (where a task/socket could >>get reclassified) to userspace as well as reports per-process wait >>times for cpu, memory, io etc. Such information can be used by user >>level tools to reclassify tasks to new classes, change class shares >>etc. > > > It sounds to me the classification engine can be moved to userspace? > > Such "classification" sounds a better suited to be done there. I suppose it could. However, one of our design objectives was to support multi-threaded server apps where each thread (task) changes its class fairly rapidly (say every time it starts doing work on behalf of a more/less important transaction). Doing a transition to userspace and back may be too costly for such a scenario. There might also be some concerns with keeping the reclassify operation atomic wrt deletion of the target class...but we haven't thought this through for userspace classification. > > Note: I haven't read the code yet. > Why just read when you can test as well :-) We just released a testing tarball at http://ckrm.sf.net.. any inputs, bugs will be most welcome ! Looking forward to more inputs, -- Shailabh