Hi, The recommended way to use io_uring for networking workloads is to use ring provided buffers. The application sets up a ring (or several) for buffers, and puts buffers for receiving data into them. When a recv completes, the completion contains information on which buffer data was received into. You can even use bundles with receive, and receive data into multiple buffers at the same time. This all works fine, but has some limitations in that a buffer is always fully consumed. This patchset adds support for partial consumption of a buffer. This, in turn, allows an application to supply fewer buffers for receives, but of a much larger size. For example, rather than add a ton of 1500b buffers for receiving data, the application can just add one large buffer. Whenever data is received, only the current head part of the buffer is consumed and used. This leads to less iteration of buffers, and also eliminates any potential wasteage of memory if some of the receives only partially fill a provided buffer. Patchset is lightly tested, passes current tests and also the new test cases I wrote for it. The liburing 'pbuf-ring-inc' branch has extra tests and support for this. Using incrementally consumed buffers from an application point of view is fairly trivial. Just pass the flag IOU_PBUF_RING_INC to io_uring_setup_buf_ring(), and this marks this buffer group ID as being incrementally consumed. Outside of that, the application just needs to keep track of where the current read/recv point is at. See patch 3 for details. Patch 1+2 are just basic prep patches, patch 3 is the meat of it. But still pretty darn simple. Note that this feature ONLY works with ring provide buffers, not with legacy/classic provided buffers. Code can also be found here, along with some other patches on top which aren't strictly related: https://git.kernel.dk/cgit/linux/log/?h=io_uring-net-coalesce and it's based on 6.11-rc3 with the pending 6.12 io_uring patches pulled in first. Comments/reviews welcome! I'll add support for this to examples/proxy in the liburing repo, and can provide some performance results post that. include/uapi/linux/io_uring.h | 8 ++++++ io_uring/io_uring.c | 2 +- io_uring/kbuf.c | 28 +++++++++--------- io_uring/kbuf.h | 54 ++++++++++++++++++++++++++--------- io_uring/net.c | 8 +++--- io_uring/rw.c | 8 +++--- 6 files changed, 71 insertions(+), 37 deletions(-) -- Jens Axboe
