On Fri, Nov 15, 2024 at 07:03:28PM +0000, Pavel Begunkov wrote: >>> but that shouldn't be PI specific. >> >> Why would anyone not use the SQE128 version? > > !SQE128 with user pointer can easily be faster depending on the > ratio of requests that use SQE128 and don't. E.g. one PI read > following with a 100 of send/recv on average. copy_from_user > is not _that_ expensive and we're talking about zeroing an > extra never used afterwards cache line. Why would you use the same ring for it? Remember PI is typically used by thing like databases. Everything that does disk I/O will use it, so optimizing for it actually being used absolutely makes sense.
