On 2/10/23 3:41?PM, David Laight wrote: > From: Linus Torvalds >> Sent: 10 February 2023 17:24 > ... >> And when it comes to networking, in general things like TCP checksums >> etc should be ok even with data that isn't stable. When doing things >> by hand, networking should always use the "copy-and-checksum" >> functions that do the checksum while copying (so even if the source >> data changes, the checksum is going to be the checksum for the data >> that was copied). >> >> And in many (most?) smarter network cards, the card itself does the >> checksum, again on the data as it is transferred from memory. >> >> So it's not like "networking needs a stable source" is some really >> _fundamental_ requirement for things like that to work. > > It is also worth remembering that TCP needs to be able > to retransmit the data and a much later time. > So the application must not change the data until it has > been acked by the remote system. This has been covered, and: > I don't think io_uring has any way to indicate anything > other than 'the data has been accepted by the socket'. This is wrong and has also been covered. -- Jens Axboe
