On 30.08.19 08:01, Michal Hocko wrote: > On Thu 29-08-19 18:59:31, David Hildenbrand wrote: >> On 29.08.19 18:27, Michal Hocko wrote: > [...] >>> No rush, really... It seems this is quite unlikely event as most hotplug >>> usecases simply online memory before removing it later on. >>> >> >> I can trigger it reliably right now while working/testing virtio-mem, so >> I finally want to clean up this mess :) (has been on my list for a long >> time). I'll try to hunt for the right commit id's that broke it. > > f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to > zones until online") > Right, I can see that that commit still does a set_page_node(page, nid); SetPageReserved(page); for every added page. But of course the zone_idx might contain garbage. So for this garbage pointer, f1dd2cd13c4b seems to be the right one. Regarding shrink_zone_span(), I suspect it was introduced by d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") -- Thanks, David / dhildenb