From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sd0208e0.au.ibm.com (d23rh904.au.ibm.com [202.81.18.202]) by ausmtp05.au.ibm.com (8.13.8/8.13.6) with ESMTP id kALN8ueL540734 for ; Tue, 21 Nov 2006 22:09:12 -0100 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.250.237]) by sd0208e0.au.ibm.com (8.13.6/8.13.6/NCO v8.1.1) with ESMTP id kALBADnO133388 for ; Tue, 21 Nov 2006 22:10:24 +1100 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id kALB6kam021555 for ; Tue, 21 Nov 2006 22:06:46 +1100 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 MIME-Version: 1.0 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: owner-linux-mm@kvack.org Return-Path: 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 List-ID: 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org