From a2741c58ac677e5de35bba7dec6376579dd513cd Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 17 May 2023 12:23:41 -0600 Subject: [PATCH] io_uring/net: don't retry recvmsg() unnecessarily If we're doing multishot receives, then we always end up doing two trips through sock_recvmsg(). For protocols that sanely set msghdr->msg_inq, then we don't need to waste time picking a new buffer and attempting a new receive if there's nothing there. Signed-off-by: Jens Axboe --- io_uring/net.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/io_uring/net.c b/io_uring/net.c index 9e0034771dbb..0795f3783013 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -635,7 +635,15 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret, if (io_aux_cqe(req->ctx, issue_flags & IO_URING_F_COMPLETE_DEFER, req->cqe.user_data, *ret, cflags | IORING_CQE_F_MORE, true)) { io_recv_prep_retry(req); - return false; + /* Known not-empty or unknown state, retry */ + if (cflags & IORING_CQE_F_SOCK_NONEMPTY || + msg->msg_inq == -1U) + return false; + if (issue_flags & IO_URING_F_MULTISHOT) + *ret = IOU_ISSUE_SKIP_COMPLETE; + else + *ret = -EAGAIN; + return true; } /* Otherwise stop multishot but use the current result. */ }