On 2/10/23 1:36 PM, Linus Torvalds wrote: > On Fri, Feb 10, 2023 at 12:32 PM Jens Axboe <axboe@xxxxxxxxx> wrote: >> >> No, we very much do have that for io_uring zerocopy sends, which was in >> the bit below you snipped from the reply. It'll tell you when data has >> been sent out, and when the data has been acked. > > Hmm. splice() itself definitely doesn't have that data - there's no > "io context" for it. > > There is only the pipe buffers, and they are released when the data > has been accepted - which is not the same as used (eg the networking > layer just takes another ref to the page and says "I'm done"). > > Maybe adding some io context to the pipe buffer would be possible, but > it's certainly not obvious how, without changing splice() semantics > completely. 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. -- Jens Axboe
