On Thu, Feb 28, 2019 at 03:08:17PM +0100, Michal Hocko wrote: > On Thu 28-02-19 14:40:54, Oscar Salvador wrote: > > On Thu, Feb 28, 2019 at 01:11:15PM +0100, Michal Hocko wrote: > > > On Thu 28-02-19 11:19:52, Oscar Salvador wrote: > > > > On Thu, Feb 28, 2019 at 10:55:35AM +0100, Michal Hocko wrote: > > > > > You seemed to miss my point or I am wrong here. If scan_movable_pages > > > > > skips over a hugetlb page then there is nothing to migrate it and it > > > > > will stay in the pfn range and the range will not become idle. > > > > > > > > I might be misunterstanding you, but I am not sure I get you. > > > > > > > > scan_movable_pages() can either skip or not a hugetlb page. > > > > In case it does, pfn will be incremented to skip the whole hugetlb > > > > range. > > > > If that happens, pfn will hold the next non-hugetlb page. > > > > > > And as a result the previous hugetlb page doesn't get migrated right? > > > What does that mean? Well, the page is still in use and we cannot > > > proceed with offlining because the full range is not isolated right? > > > > I might be clumsy today but I still fail to see the point of concern here. > > No, it's me who is daft. I have misread the patch and seen that also > page_huge_active got removed. Now it makes perfect sense to me because > active pages are still handled properly. Heh, no worries. Glad we got the point, I was just scratching my head like a monkey. > I will leave the decision whether to split up the patch to you. On a second thought, I will split it up. One of the changes is merely to remove a redundant check, while the other is actually the one that enables the system to be able to proceed with gigantic pages, so not really related. > Acked-by: Michal Hocko <mhocko@xxxxxxxx> Thanks! -- Oscar Salvador SUSE L3
