Re: [PATCH 2/3] io_uring/poll: flag request as having gone through poll wake machinery

[Pavel Begunkov <asml.silence@gmail.com>]

On 7/12/25 00:59, Jens Axboe wrote:
> No functional changes in this patch, just in preparation for being able
> to flag completions as having completed via being triggered from poll.
> 
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> ---
>   include/linux/io_uring_types.h | 3 +++
>   io_uring/poll.c                | 1 +
>   2 files changed, 4 insertions(+)
> 
> diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
> index 80a178f3d896..b56fe2247077 100644
> --- a/include/linux/io_uring_types.h
> +++ b/include/linux/io_uring_types.h
> @@ -505,6 +505,7 @@ enum {
>   	REQ_F_HAS_METADATA_BIT,
>   	REQ_F_IMPORT_BUFFER_BIT,
>   	REQ_F_SQE_COPIED_BIT,
> +	REQ_F_POLL_WAKE_BIT,
>   
>   	/* not a real bit, just to check we're not overflowing the space */
>   	__REQ_F_LAST_BIT,
> @@ -596,6 +597,8 @@ enum {
>   	REQ_F_IMPORT_BUFFER	= IO_REQ_FLAG(REQ_F_IMPORT_BUFFER_BIT),
>   	/* ->sqe_copy() has been called, if necessary */
>   	REQ_F_SQE_COPIED	= IO_REQ_FLAG(REQ_F_SQE_COPIED_BIT),
> +	/* request went through poll wakeup machinery */
> +	REQ_F_POLL_WAKE		= IO_REQ_FLAG(REQ_F_POLL_WAKE_BIT),
>   };
>   
>   typedef void (*io_req_tw_func_t)(struct io_kiocb *req, io_tw_token_t tw);
> diff --git a/io_uring/poll.c b/io_uring/poll.c
> index c7e9fb34563d..e1950b744f3b 100644
> --- a/io_uring/poll.c
> +++ b/io_uring/poll.c
> @@ -423,6 +423,7 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
>   			else
>   				req->flags &= ~REQ_F_SINGLE_POLL;
>   		}
> +		req->flags |= REQ_F_POLL_WAKE;

Same, it's overhead for all polled requests for a not clear gain.
Just move it to the arming function. It's also not correct to
keep it here, if that's what you care about.

>   		__io_poll_execute(req, mask);
>   	}
>   	return 1;

-- 
Pavel Begunkov