On Tue 24-07-18 16:13:09, David Hildenbrand wrote: [...] > So I see right now: > > - Pg_reserved + e.g. new page type (or some other unique identifier in > combination with Pg_reserved) > -> Avoid reads of pages we know are offline > - extend is_ram_page() > -> Fake zero memory for pages we know are offline > > Or even both (avoid reading and don't crash the kernel if it is being done). I really fail to see how that can work without kernel being aware of PageOffline. What will/should happen if you run an old kdump tool on a kernel with this partially offline memory? -- Michal Hocko SUSE Labs