Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265236AbUD3TsV (ORCPT ); Fri, 30 Apr 2004 15:48:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265238AbUD3TsV (ORCPT ); Fri, 30 Apr 2004 15:48:21 -0400 Received: from mtagate4.uk.ibm.com ([195.212.29.137]:49319 "EHLO mtagate4.uk.ibm.com") by vger.kernel.org with ESMTP id S265236AbUD3TsT (ORCPT ); Fri, 30 Apr 2004 15:48:19 -0400 Message-ID: <4092AD60.1030809@watson.ibm.com> Date: Fri, 30 Apr 2004 15:47:44 -0400 From: Shailabh 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: Rik van Riel CC: Christoph Hellwig , linux-kernel , ckrm-tech , Jeff Dike Subject: Re: [ckrm-tech] Re: [RFC] Revised CKRM release References: <20040430174117.A13372@infradead.org> In-Reply-To: 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 Content-Length: 1109 Lines: 34 Rik van Riel wrote: > On Fri, 30 Apr 2004, Christoph Hellwig wrote: > > >>I'd hate to see this in the kernel unless there's a very strong need >>for it and no way to solve it at a nicer layer of abstraction, e.g. >>userland virtual machines ala uml/umlinux. > > > User Mode Linux could definitely be an option for implementing > resource management, provided that the overhead can be kept > low enough. > > For these purposes, "low enough" could be as much as 30% > overhead, since that would still allow people to grow the > utilisation of their server from a typical 10-20% to as > much as 40-50%. > http://www.cl.cam.ac.uk/Research/SRG/netos/xen/performance.html has some numbers comparing native Linux to UML (and against the Xen virtual machine monitor) but its on a 2.4 kernel. Jeff, do you have any numbers for UML overhead in 2.6 ? -- Shailabh - 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/