Re: [PATCHv3 0/3] io_uring: mixed submission queue size support

[Keith Busch <kbusch@kernel.org>]

Resend for missing subject... I keep pointing to the wrong directory
after merging the liburing and kernel cover letters.

On Wed, Sep 24, 2025 at 08:12:06AM -0700, Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
> 
> Previous version:
> 
>   https://lore.kernel.org/io-uring/20250904192716.3064736-1-kbusch@meta.com/
> 
> The CQ supports mixed size entries, so why not for SQ's too? There are
> use cases that currently allocate different queues just to keep these
> things separated, but we can efficiently handle both cases in a single
> ring.
> 
> Changes since v2:
> 
>  - Define 128B opcodes to be used on mixed SQs. This is done instead of
>    using the last SQE flags bit to generically identify a command as
>    such. The new opcodes are valid only on a mixed SQ.
> 
>  - Fixed up the accounting of sqes left to dispatch. The big sqes on a
>    mixed sq count for two entries, so previously would have fetched too
>    many.
> 
>  - liburing won't bother submitting the nop-skip for the wrap-around
>    condition if there are not enoungh free entries for the big-sqe.
> 
> kernel:
> 
> Keith Busch (1):
>   io_uring: add support for IORING_SETUP_SQE_MIXED
> 
>  include/uapi/linux/io_uring.h |  8 ++++++++
>  io_uring/fdinfo.c             | 34 +++++++++++++++++++++++++++-------
>  io_uring/io_uring.c           | 27 +++++++++++++++++++++++----
>  io_uring/io_uring.h           |  8 +++++---
>  io_uring/opdef.c              | 26 ++++++++++++++++++++++++++
>  io_uring/opdef.h              |  2 ++
>  io_uring/register.c           |  2 +-
>  io_uring/uring_cmd.c          | 12 ++++++++++--
>  io_uring/uring_cmd.h          |  1 +
>  9 files changed, 103 insertions(+), 17 deletions(-)
> 
> liburing:
> 
> Keith Busch (3):
>   Add support IORING_SETUP_SQE_MIXED
>   Add nop testing for IORING_SETUP_SQE_MIXED
>   Add mixed sqe test for uring commands
> 
>  src/include/liburing.h          |  50 +++++++++++
>  src/include/liburing/io_uring.h |  11 +++
>  test/Makefile                   |   3 +
>  test/sqe-mixed-bad-wrap.c       |  89 ++++++++++++++++++++
>  test/sqe-mixed-nop.c            |  82 ++++++++++++++++++
>  test/sqe-mixed-uring_cmd.c      | 142 ++++++++++++++++++++++++++++++++
>  6 files changed, 377 insertions(+)
>  create mode 100644 test/sqe-mixed-bad-wrap.c
>  create mode 100644 test/sqe-mixed-nop.c
>  create mode 100644 test/sqe-mixed-uring_cmd.c
> 
> -- 
> 2.47.3
> 
>