Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946563AbWKJM4L (ORCPT ); Fri, 10 Nov 2006 07:56:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946564AbWKJM4K (ORCPT ); Fri, 10 Nov 2006 07:56:10 -0500 Received: from ausmtp05.au.ibm.com ([202.81.18.154]:4602 "EHLO ausmtp05.au.ibm.com") by vger.kernel.org with ESMTP id S1946563AbWKJM4J (ORCPT ); Fri, 10 Nov 2006 07:56:09 -0500 Message-ID: <455476C0.6010204@in.ibm.com> Date: Fri, 10 Nov 2006 18:25:28 +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: Pavel Emelianov CC: dev@openvz.org, ckrm-tech@lists.sourceforge.net, haveblue@us.ibm.com, Linux Kernel Mailing List , Linux MM , rohitseth@google.com Subject: Re: [ckrm-tech] [RFC][PATCH 6/8] RSS controller shares allocation References: <20061109193523.21437.86224.sendpatchset@balbir.in.ibm.com> <20061109193619.21437.84173.sendpatchset@balbir.in.ibm.com> <45544240.80609@openvz.org> <45545429.7080903@in.ibm.com> <4554552E.8050300@openvz.org> In-Reply-To: <4554552E.8050300@openvz.org> 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: 1719 Lines: 52 Pavel Emelianov wrote: > [snip] > >>>> + for_each_child(child, res->rgroup) { >>>> + child_res = get_memctlr(child); >>>> + BUG_ON(!child_res); >>>> + recalc_and_propagate(child_res, res); >>> Recursion? Won't it eat all the stack in case of a deep tree? >> The depth of the hierarchy can be controlled. Recursion is needed >> to do a DFS walk > > That's another point against recursion - bad root can > crash the kernel... If we are about to give container's > users ability to make their own subtrees then we *must* > avoid recursion. There's an algorithm that allows one > to walk the tree like this w/o recursion. Bad pointers are always bad, whether they are the root or any other pointer. Tree traversal is a generic infrastructure issue for any infrastructure that supports a hierarchy. Are you talking about threaded trees? Yes, they can be traversed without recursion. I need to recheck my DS reference to double check. > > [snip] > >>> I didn't find where in this patches this callback is called. >> It's a part of the resource groups infrastructure. It's been ported >> on top of Paul Menage's containers patches. The code can be easily >> adapted to work directly with containers instead of resource groups >> if required. > > > Could you please give me a link to the patch where this > is called? Please see http://www.mail-archive.com/ckrm-tech@lists.sourceforge.net/msg03333.html -- 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/