Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751864AbWHUK7l (ORCPT ); Mon, 21 Aug 2006 06:59:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751862AbWHUK7k (ORCPT ); Mon, 21 Aug 2006 06:59:40 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:15131 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S1751864AbWHUK7k (ORCPT ); Mon, 21 Aug 2006 06:59:40 -0400 Message-ID: <44E992B9.8080908@sw.ru> Date: Mon, 21 Aug 2006 15:02:17 +0400 From: Kirill Korotaev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060417 X-Accept-Language: en-us, en, ru MIME-Version: 1.0 To: Matt Helsley CC: "Chandra S. Seetharaman" , Rik van Riel , CKRM-Tech , Linux Kernel Mailing List , Andi Kleen , Christoph Hellwig , Andrey Savochkin , devel@openvz.org, hugh@veritas.com, Ingo Molnar , Alan Cox , Pavel Emelianov , Andrew Morton Subject: Re: [ckrm-tech] [RFC][PATCH 2/7] UBC: core (structures, API) References: <44E33893.6020700@sw.ru> <44E33BB6.3050504@sw.ru> <1155866328.2510.247.camel@stark> <44E5A637.1020407@sw.ru> <1155955116.2510.445.camel@stark> In-Reply-To: <1155955116.2510.445.camel@stark> 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: 1045 Lines: 27 >>>>+ for (p = ub; p != NULL; p = p->parent) { >>> >>> >>>Seems rather expensive to walk up the tree for every charge. Especially >>>if the administrator wants a fine degree of resource control and makes a >>>tall tree. This would be a problem especially when it comes to resources >>>that require frequent and fast allocation. >> >>in heirarchical accounting you always have to update all the nodes :/ >>with flat UBC this doesn't introduce significant overhead. > > > Except that you eventually have to lock ub0. Seems that the cache line > for that spinlock could bounce quite a bit in such a hot path. do you mean by ub0 host system ub which we call ub0 or you mean a top ub? > Chandra, doesn't Resource Groups avoid walking more than 1 level up the > hierarchy in the "charge" paths? Kirill - 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/