Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030864AbWKULHW (ORCPT ); Tue, 21 Nov 2006 06:07:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934261AbWKULHW (ORCPT ); Tue, 21 Nov 2006 06:07:22 -0500 Received: from ausmtp04.au.ibm.com ([202.81.18.152]:19445 "EHLO ausmtp04.au.ibm.com") by vger.kernel.org with ESMTP id S1030864AbWKULHV (ORCPT ); Tue, 21 Nov 2006 06:07:21 -0500 Message-ID: <4562DDBE.5070706@in.ibm.com> Date: Tue, 21 Nov 2006 16:36:38 +0530 From: Balbir Singh Reply-To: balbir@in.ibm.com Organization: IBM User-Agent: Thunderbird 1.5.0.7 (X11/20060922) MIME-Version: 1.0 To: "Patrick.Le-Dot" CC: ckrm-tech@lists.sourceforge.net, dev@openvz.org, haveblue@us.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rohitseth@google.com Subject: Re: [RFC][PATCH 5/8] RSS controller task migration support References: <20061121100150.9ECCF1B6AC@openx4.frec.bull.fr> In-Reply-To: <20061121100150.9ECCF1B6AC@openx4.frec.bull.fr> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2153 Lines: 70 Patrick.Le-Dot wrote: > On Fri, 17 Nov 2006 22:04:08 +0530 >> ... >> I am not against guarantees, but >> >> Consider the following scenario, let's say we implement guarantees >> >> 1. If we account for kernel resources, how do you provide guarantees >> when you have non-reclaimable resources? > > First, the current patch is based only on pages available in the > struct mm. > I doubt that these pages are "non-reclaimable"... I am speaking of a scenario when we start supporting kernel accounting and of-course the swapless case. > > And guarantee should be ignored just because some kernel resources > are marked "non-reclaimable" ? > Ok.. but can you have a consistent guarantee definition with un-reclaimable kernel resources? How do you define a guarantee in a consistent manner? In my discussions earlier on lkml, I had suggested that we define guarantee only for reclaimable resources and provide support only for them. > >> 2. If a customer runs a system with swap turned off (which is quite >> common), > > quite common, really ? Yep, I was listening to a talk from a customer service expert and he mentioned that it's used to boost performance. > >> then anonymous memory becomes irreclaimable. If a group >> takes more than it's fair share (exceeds its guarantee), you >> have scenario similar to 1 above. > > That seems to be just a subset of the "guarantee+limit" model : if > guarantee is not useful for you, don't use it. > > I'm not saying that guarantee should be a magic piece of code working > for everybody. > > But we have to propose something for the customers who ask for a > guarantee (ie using a system with swap turned on like me and this is > quite common:-) > Like I said I am not against guarantees, but do we have to implement them in our first iteration? > Patrick > -- 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/