Hi Pavel, hi Jens, I did some initial testing with IORING_OP_SEND_ZC. While reading the code I think I found a race that can lead to IORING_CQE_F_MORE being missing even if the net layer got references. While there I added some code to allow userpace to know how effective the IORING_OP_SEND_ZC attempt was, in order to avoid it it's not used (e.g. on a long living tcp connection). This change requires a change to the existing test, see: https://github.com/metze-samba/liburing/tree/test-send-zerocopy Stefan Metzmacher (5): io_uring/opdef: rename SENDZC_NOTIF to SEND_ZC io_uring/core: move io_cqe->fd over from io_cqe->flags to io_cqe->res io_uring/core: keep req->cqe.flags on generic errors io_uring/net: let io_sendzc set IORING_CQE_F_MORE before sock_sendmsg() io_uring/notif: let userspace know how effective the zero copy usage was include/linux/io_uring_types.h | 6 +++--- io_uring/io_uring.c | 18 +++++++++++++----- io_uring/net.c | 19 +++++++++++++------ io_uring/notif.c | 18 ++++++++++++++++++ io_uring/opdef.c | 2 +- net/ipv4/ip_output.c | 3 ++- net/ipv4/tcp.c | 2 ++ net/ipv6/ip6_output.c | 3 ++- 8 files changed, 54 insertions(+), 17 deletions(-) -- 2.34.1
