lpar issue for ZONE_DEVICE p2pmem in 4.14-rc

[Stephen Bates]

> I am guessing that the hotplug of ZONE_DEVICE memory was done
> incorrectly as it lead to HPT resizing (the system thinking this is
> normal memory). Ideally one would expect that the driver would online
> ZONE_DEVICE memory and not go through the HOTPLUG path. Are you using
> devm_memremap_pages() path to add these pages?
>

Thanks for the response Balbir. Yes we use devm_memremap_pages() to add these pages and it does call arch_add_memory(). We do have an alternate set of patches which still calls devm_memremap_pages() but can take a flag to indicate the memory being added is io memory and uses io_remap() rather than arch_add_memory() for that type of memory [1]. Would that be a better approach for this arch? I can try and apply this patch but __add_pages() has gone through some changes recently so it will take me a few days to get to that. 

Stephen

[1] https://github.com/sbates130272/linux-p2pmem/commit/ac735871fcd2c63bd33c814aa3941ca3ef53b636