On Tue, 2019-02-26 at 20:40 +0100, Michal Hocko wrote: > It seems you have missed the point of my question. It simply doesn't > make much sense to have offline memory mapped. That memory is not > accessible in general. So mapping it at the offline time is dubious at > best. Well, kernel_map_pages() is like other debug features which could look "unusual". > Also you do not get through the offlining phase on a newly > hotplugged (and not yet onlined) memory. So the patch doesn't look > correct to me and it all smells like the bug you are seeing is a wrong > reporting. > That (physical memory hotadd) is a special case like during the boot. The patch is strictly to deal with offline/online memory, i.e., logical/soft memory hotplug.
