On Thu 21-03-19 11:03:18, Anshuman Khandual wrote: > > > On 03/21/2019 10:31 AM, Zi Yan wrote: > > On 20 Mar 2019, at 21:13, Anshuman Khandual wrote: > > > >> pfn_valid_within() calls pfn_valid() when CONFIG_HOLES_IN_ZONE making it > >> redundant for both definitions (w/wo CONFIG_MEMORY_HOTPLUG) of the helper > >> pfn_to_online_page() which either calls pfn_valid() or pfn_valid_within(). > >> pfn_valid_within() being 1 when !CONFIG_HOLES_IN_ZONE is irrelevant either > >> way. This does not change functionality. > >> > >> Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages") > > > > I would not say this patch fixes the commit 2ce13640b3f4 from 2017, > > because the pfn_valid_within() in pfn_to_online_page() was introduced by > > a recent commit b13bc35193d9e last month. :) > > Right, will update the tag with this commit. The patch is correct but I wouldn't bother to add Fixes tag at all. The current code is obviously not incorrect. Do you see any actual performance issue? -- Michal Hocko SUSE Labs