Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265227AbUD3TRc (ORCPT ); Fri, 30 Apr 2004 15:17:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265229AbUD3TRc (ORCPT ); Fri, 30 Apr 2004 15:17:32 -0400 Received: from mtagate1.uk.ibm.com ([195.212.29.134]:24488 "EHLO mtagate1.uk.ibm.com") by vger.kernel.org with ESMTP id S265227AbUD3TRa (ORCPT ); Fri, 30 Apr 2004 15:17:30 -0400 Message-ID: <4092A636.7050304@watson.ibm.com> Date: Fri, 30 Apr 2004 15:17:10 -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: Rik van Riel CC: Christoph Hellwig , linux-kernel , ckrm-tech Subject: Re: [ckrm-tech] Re: [RFC] Revised CKRM release References: 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: 1480 Lines: 43 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. ....and provided the groups of processes that are sought to be regulated as a unit are relatively static. > 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%. > In overhead, I presume you're including the overhead of running as many uml instances as expected number of classes. Not just the slowdown of applications because they're running under a uml instance (instead of running native) ? I think UML is justified more from a fault-containment point of view (where overheads are a lower priority) than from a performance isolation viewpoint. In any case, a 30% overhead would send a large batch of higher-end server admins running to get a stick to beat you with :-) - 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/