Re: [v1 2/2] device-dax: "Hotremove" persistent memory that is used like normal RAM

> + > + /* Walk and offline every singe memory_block of the dax region. */ > + lock_device_hotplug(); > + rc = walk_memory_range(start_pfn, end_pfn, dev, offline_memblock_cb); > + unlock_device_hotplug(); > + if (rc) > + return rc; This potential early return is the reason why memory hotremove is not reliable vs the driver-core. If this walk fails to offline the memory it will still be online, but the driver-core has no consideration for device-unbind failing. The ubind will proceed while the memory stays pinned.