Re: [PATCH] io_uring/net: Allow to do vectorized send

[Jens Axboe <axboe@kernel.dk>]

On 7/23/25 11:16 PM, norman.maurer@googlemail.com wrote:
> From: Norman Maurer <norman_maurer@apple.com>
> 
> At the moment you have to use sendmsg for vectorized send. While this
> works it's suboptimal as it also means you need to allocate a struct
> msghdr that needs to be kept alive until a submission happens. We can
> remove this limitation by just allowing to use send directly.

Looks pretty clean, just a few minor comments below. For the commit
message above, you should wrap it at ~72 chars.

> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index b8a0e70ee2fd..6957dc539d83 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -392,12 +392,16 @@ enum io_uring_op {
>   *				the starting buffer ID in cqe->flags as per
>   *				usual for provided buffer usage. The buffers
>   *				will be	contiguous from the starting buffer ID.
> + *
> + * IORING_SEND_VECTORIZED	If set, SEND[_ZC] will take a pointer to a io_vec
> + * 				to allow vectorized send operations.
>   */
>  #define IORING_RECVSEND_POLL_FIRST	(1U << 0)
>  #define IORING_RECV_MULTISHOT		(1U << 1)
>  #define IORING_RECVSEND_FIXED_BUF	(1U << 2)
>  #define IORING_SEND_ZC_REPORT_USAGE	(1U << 3)
>  #define IORING_RECVSEND_BUNDLE		(1U << 4)
> +#define IORING_SEND_VECTORIZED		(1U << 5)

Do we want to support this on the recv side too? I guess that can be
added later and IORING_RECV_VECTORIZED can just be defined to
IORING_SEND_VECTORIZED in that case.

> diff --git a/io_uring/net.c b/io_uring/net.c
> index ba2d0abea349..d4a59f5461ed 100644
> --- a/io_uring/net.c
> +++ b/io_uring/net.c
> @@ -420,6 +424,9 @@ int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>  	sr->flags = READ_ONCE(sqe->ioprio);
>  	if (sr->flags & ~SENDMSG_FLAGS)
>  		return -EINVAL;
> +        if (req->opcode != IORING_OP_SEND && req->opcode != IORING_OP_SEND_ZC && sr->flags & IORING_SEND_VECTORIZED)
> +                return -EINVAL;
> +

	if (req->opcode == IORING_OP_SENDMSG && sr->flags & IORING_SEND_VECTORIZED)
		return -EINVAL;

?

-- 
Jens Axboe