From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 6 May 2012 23:17:15 +0800 From: Richard Yang To: Yinghai Lu Cc: Richard Yang , Wei Yang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: One problem in reassign pci bus number? Message-ID: <20120506151715.GA7773@richard> Reply-To: Richard Yang References: <20120422155202.GA13540@richard> <20120503065455.GA30042@richard> <20120504024721.GA6775@richard> <20120504045205.GA21624@richard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: On Fri, May 04, 2012 at 10:37:08AM -0700, Yinghai Lu wrote: >On Thu, May 3, 2012 at 9:52 PM, Richard Yang wrote: >> >> BTW, even if this value is returned by __find_res_top_free_size(), or >> returned after this function is called, the purpose of the >> __find_res_top_free_size() is to get the biggest free space under the >> first parameter? > >__find_res_top_free_size() is used to get size just under top, and >then use it to calculate size above top that need to be extended. > >at last will combine free size under top and allocated size above top >and return. Yes, I get the general idea. then I want to confirm which size __find_res_top_free_size() will return. Come to the previous question, for one resource like this. res = 90-150 ->child 105-140 We call __find_res_top_free_size(res, 1); This function should return which size? 10? 15? or 25? >>From the code + ret = __allocate_resource(res, &tmp_res, n_size, + res->end - n_size + skip_nr, res->end, + 1, NULL, NULL, false); I think it will check the free space near the end of res. I did one test on __find_res_top_free_size(res, 1) of this example. And returned 10. Which means, it find the free space (141-150). So I want to confirm this function really returns the size of free space at the end of the res. not the biggest one or the sum. > >Yinghai -- Richard Yang Help you, Help me