On Mon, Jan 28, 2019 at 1:26 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > On Fri 25-01-19 11:15:08, Dan Williams wrote: > [...] > > However, we should consider this along with the userspace enabling to > > control which device-dax instances are set aside for hotplug. It would > > make sense to have a "clear errors before hotplug" configuration > > option. > > I am not sure I understand. Do you mean to clear HWPoison when the > memory is hotadded (add_pages) or onlined (resp. move_pfn_range_to_zone)? Before the memory is hot-added via the kmem driver it shows up as an independent persistent memory namespace. A namespace can be configured as a block device and errors cleared by writing to the given "bad block". Once all media errors are cleared the namespace can be assigned as volatile memory to the core-kernel mm. The memory range starts as a namespace each boot and must be hotplugged via startup scripts, those scripts can be made to handle the bad block pruning.
