diff options
| author | Dylan Yudaken <dylany@fb.com> | 2022-06-30 12:12:29 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-25 03:39:17 +0300 |
| commit | b3fdea6ecb55c3ceea866ff66486927e51a982b3 (patch) | |
| tree | a10146a5ecc4c71962b1c50ac9fca6730a3b41be /include/uapi | |
| parent | cbd25748545c709d35734deb9220e0af0a69e5d2 (diff) | |
| download | linux-b3fdea6ecb55c3ceea866ff66486927e51a982b3.tar.xz | |
io_uring: multishot recv
Support multishot receive for io_uring.
Typical server applications will run a loop where for each recv CQE it
requeues another recv/recvmsg.
This can be simplified by using the existing multishot functionality
combined with io_uring's provided buffers.
The API is to add the IORING_RECV_MULTISHOT flag to the SQE. CQEs will
then be posted (with IORING_CQE_F_MORE flag set) when data is available
and is read. Once an error occurs or the socket ends, the multishot will
be removed and a completion without IORING_CQE_F_MORE will be posted.
The benefit to this is that the recv is much more performant.
* Subsequent receives are queued up straight away without requiring the
application to finish a processing loop.
* If there are more data in the socket (sat the provided buffer size is
smaller than the socket buffer) then the data is immediately
returned, improving batching.
* Poll is only armed once and reused, saving CPU cycles
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-11-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/io_uring.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index cf95354198a3..499679134961 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -263,8 +263,13 @@ enum io_uring_op { * or receive and arm poll if that yields an * -EAGAIN result, arm poll upfront and skip * the initial transfer attempt. + * + * IORING_RECV_MULTISHOT Multishot recv. Sets IORING_CQE_F_MORE if + * the handler will continue to report + * CQEs on behalf of the same SQE. */ #define IORING_RECVSEND_POLL_FIRST (1U << 0) +#define IORING_RECV_MULTISHOT (1U << 1) /* * accept flags stored in sqe->ioprio |