On 21/05/18 04:35 PM, Dan Williams wrote: > + /* > + * For device private memory we call add_pages() as we only need to > + * allocate and initialize struct page for the device memory. More- > + * over the device memory is un-accessible thus we do not want to > + * create a linear mapping for the memory like arch_add_memory() > + * would do. > + * > + * For all other device memory types, which are accessible by > + * the CPU, we do want the linear mapping and thus use > + * arch_add_memory(). > + */ > + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { > + error = add_pages(nid, align_start >> PAGE_SHIFT, > + align_size >> PAGE_SHIFT, NULL, false); > + } else { > + struct zone *zone; > + > + error = arch_add_memory(nid, align_start, align_size, altmap, > + false); > + zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE]; > + if (!error) > + move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT, > align_size >> PAGE_SHIFT, altmap); > + } Maybe I missed it in the patch but, don't we need the same thing in devm_memremap_pages_release() such that it calls the correct remove function? Similar to the replaced hmm code: > - mem_hotplug_begin(); > - if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) > - __remove_pages(zone, start_pfn, npages, NULL); > - else > - arch_remove_memory(start_pfn << PAGE_SHIFT, > - npages << PAGE_SHIFT, NULL); > - mem_hotplug_done(); > - > - hmm_devmem_radix_release(resource); Perhaps it should be a separate patch too as it would be easier to see outside the big removal of HMM code. Logan