On 2/10/23 1:44 PM, Linus Torvalds wrote: > On Fri, Feb 10, 2023 at 12:39 PM Jens Axboe <axboe@xxxxxxxxx> wrote: >> >> Right, I'm referencing doing zerocopy data sends with io_uring, using >> IORING_OP_SEND_ZC. This isn't from a file, it's from a memory location, >> but the important bit here is the split notifications and how you >> could wire up a OP_SENDFILE similarly to what Andy described. > > Sure, I think it's much more reasonable with io_uring than with splice itself. > > So I was mainly just reacting to the "strict-splice" thing where Andy > was talking about tracking the page refcounts. I don't think anything > like that can be done at a splice() level, but higher levels that > actually know about the whole IO might be able to do something like > that. > > Maybe we're just talking past each other. Maybe slightly, as I was not really intending to comment on the strict splice thing. But yeah I agree on splice, it would not be trivial to do there. At least with io_uring we have the communication channel we need. And tracking page refcounts seems iffy and fraught with potential issues. -- Jens Axboe
