Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758174Ab2EHDnB (ORCPT ); Mon, 7 May 2012 23:43:01 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:58655 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755225Ab2EHDnA convert rfc822-to-8bit (ORCPT ); Mon, 7 May 2012 23:43:00 -0400 MIME-Version: 1.0 In-Reply-To: <20120508024612.GA11485@richard> References: <20120504024721.GA6775@richard> <20120504045205.GA21624@richard> <20120506151715.GA7773@richard> <20120507011722.GA8122@richard> <20120508024612.GA11485@richard> Date: Mon, 7 May 2012 20:42:59 -0700 X-Google-Sender-Auth: taEaWfiw1LQVhSlTsbdTmnb7_cc Message-ID: Subject: Re: One problem in reassign pci bus number? From: Yinghai Lu To: Richard Yang Cc: Wei Yang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1680 Lines: 44 On Mon, May 7, 2012 at 7:46 PM, Richard Yang wrote: > On Sun, May 06, 2012 at 07:04:09PM -0700, Yinghai Lu wrote: >>On Sun, May 6, 2012 at 6:17 PM, Richard Yang wrote: >>> so this free space will be combined with the free space got from >>> parent, form a big space to meet the requirement. >>> >>> This is the general idea about probe_resource()? >>> >>> And this is the design decision to find the free space at the end >>> of top, even at the start we have more free space? >> >>no, probe_resource will get from start if space is big enough. >> >>if not, it will try to extend top. > > Hmm... for example we still have this > ? ? ? ? ? ? ? parent[70-160] > brother1[70-80] ?res[90-150] ?brother2[151-160] > ? ? ? ? ? ? ? ? ? ->child[105-140] > > if we call probe_resource(res, new_res, 16, par, 1, 0xff, > IORESOURCE_PCI_FIXED); > > I think this call is used to allocate a res of size 16 under res. > When there is no enough free space, it will expend res, and res->parent. > > While in this situation, res doesn't have enough free space. so it need > to expend itself. > > In the probe_resource() it tries to extend res on the right side. > So even there is enough space between brother1 and res, I think the > probe_resource() will not return 0. > > Do you think my analysis is correct? it will reduce needed size one by one. so at last it will return [91, 104] Yinghai -- 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/