On Sun, May 06, 2012 at 09:36:35AM -0700, Yinghai Lu wrote: >On Sun, May 6, 2012 at 9:35 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: >> On Sun, May 6, 2012 at 8:17 AM, Richard Yang <weiyang@xxxxxxxxxxxxxxxxxx> wrote: >>> On Fri, May 04, 2012 at 10:37:08AM -0700, Yinghai Lu wrote: >>>>On Thu, May 3, 2012 at 9:52 PM, Richard Yang <weiyang@xxxxxxxxxxxxxxxxxx> 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. >> >> yes. it is 15, [141-150] > >should 10, aka [141-150] Thanks, 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? -- Richard Yang Help you, Help me -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
