mm/rmap: try_to_migrate() skip zone_device !device_private

I know nothing about zone_device pages and !device_private pages; but if
try_to_migrate_one() will do nothing for them, then it's better that
try_to_migrate() filter them first, than trawl through all their vmas.

Signed-off-by: Hugh Dickins <>
Reviewed-by: Shakeel Butt <>
Reviewed-by: Alistair Popple <>
Cc: Andrew Morton <>
Cc: Jason Gunthorpe <>
Cc: Ralph Campbell <>
Cc: Christoph Hellwig <>
Cc: Yang Shi <>
Cc: Kirill A. Shutemov <>
Signed-off-by: Linus Torvalds <>
1 file changed