On Tue, Nov 07, 2017 at 06:44:47PM +0900, Jaewon Kim wrote: > online_page_ext and page_ext_init allocate page_ext for each section, but > they do not allocate if the first PFN is !pfn_present(pfn) or > !pfn_valid(pfn). > > Though the first page is not valid, page_ext could be useful for other > pages in the section. But checking all PFNs in a section may be time > consuming job. Let's check each (section count / 16) PFN, then prepare > page_ext if any PFN is present or valid.
I guess that this kind of section is not so many. And, this is for debugging so completeness would be important. It's better to check all pfn in the section. Thanks.
