On Tue, May 7, 2019 at 10:02 AM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > I got it wrong then. I'll fix it up and get efad4e475c31 in instead. Careful. That one had a bug too, and we have 891cb2a72d82 ("mm, memory_hotplug: fix off-by-one in is_pageblock_removable"). All of these were *horribly* and subtly buggy, and might be intertwined with other issues. And only trigger on a few specific machines where the memory map layout is just right to trigger some special case or other, and you have just the right config. It might be best to verify with Michal Hocko. Michal? Linus