On Tuesday, 2 March 2021 7:52:53 PM AEDT Alistair Popple wrote:

On Saturday, 27 February 2021 2:59:09 AM AEDT Christoph Hellwig wrote:

quoted

quoted

-		struct page *page = migration_entry_to_page(entry);
+		struct page *page = pfn_to_page(swp_offset(entry));

I wonder if keeping a single special_entry_to_page() helper would still
me a useful.  But I'm not entirely sure.  There are also two more open
coded copies of this in the THP migration code.

I think it might be if only to clearly document where these entries are 

used. 

Will add it for the next version to see what it looks like.

Actually the main advantage ends up being that it becomes easy to retain the 
page locked check for migration entries.

 - Alistair