On Mon, Aug 17, 2020 at 12:12:12PM -0700, Cong Wang wrote: > > So netdev people will have to understand and support PageSlab() or > page_count()? Yes. As they came up with that contrived rule what is acceptable for sendpage. No one else really knows and other subsystems like the block layer are perfectly fine with it. > > If it is unusual even for mm people, how could netdev people suppose > to understand this unusual mm bug? At least not any better. It is not a mm bug, it is a networking quirk.