Michal Hocko <mho...@kernel.org> writes: > On Tue 25-04-17 16:27:51, Laurent Dufour wrote: >> When page are poisoned, they should be uncharged from the root memory >> cgroup. >> >> This is required to avoid a BUG raised when the page is onlined back: >> BUG: Bad page state in process mem-on-off-test pfn:7ae3b >> page:f000000001eb8ec0 count:0 mapcount:0 mapping: (null) >> index:0x1 >> flags: 0x3ffff800200000(hwpoison) > > My knowledge of memory poisoning is very rudimentary but aren't those > pages supposed to leak and never come back? In other words isn't the > hoplug code broken because it should leave them alone?
Yes that would be the right interpretation. If it was really offlined due to a hardware error the memory will be poisoned and any access could cause a machine check. hwpoison has an own "unpoison" option (only used for debugging), which I think handles this. -Andi
