diff options
| author | Keith Busch <kbusch@kernel.org> | 2025-10-16 11:09:38 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-10-22 07:34:57 -0600 |
| commit | 1cba30bf9fdd6c982708f3587f609a30c370d889 (patch) | |
| tree | 4fd436dd1317c70f35eced5cb93b0b2fe857f9ff /io_uring/io_uring.h | |
| parent | 5b6d8a032e807c48a843fb81d9e3d74391f731ea (diff) | |
io_uring: add support for IORING_SETUP_SQE_MIXED
Normal rings support 64b SQEs for posting submissions, while certain
features require the ring to be configured with IORING_SETUP_SQE128, as
they need to convey more information per submission. This, in turn,
makes ALL the SQEs be 128b in size. This is somewhat wasteful and
inefficient, particularly when only certain SQEs need to be of the
bigger variant.
This adds support for setting up a ring with mixed SQE sizes, using
IORING_SETUP_SQE_MIXED. When setup in this mode, SQEs posted to the ring
may be either 64b or 128b in size. If a SQE is 128b in size, then opcode
will be set to a variante to indicate that this is the case. Any other
non-128b opcode will assume the SQ's default size.
SQEs on these types of mixed rings may also utilize NOP with skip
success set. This can happen if the ring is one (small) SQE entry away
from wrapping, and an attempt is made to get a 128b SQE. As SQEs must be
contiguous in the SQ ring, a 128b SQE cannot wrap the ring. For this
case, a single NOP SQE should be inserted with the SKIP_SUCCESS flag
set. The kernel will process this as a normal NOP and without posting a
CQE.
Signed-off-by: Keith Busch <kbusch@kernel.org>
[axboe: {} style fix and assign sqe before opcode read]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/io_uring.h')
| -rw-r--r-- | io_uring/io_uring.h | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 78777bf1ea4b..44b8091c7fcd 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -54,7 +54,8 @@ IORING_SETUP_REGISTERED_FD_ONLY |\ IORING_SETUP_NO_SQARRAY |\ IORING_SETUP_HYBRID_IOPOLL |\ - IORING_SETUP_CQE_MIXED) + IORING_SETUP_CQE_MIXED |\ + IORING_SETUP_SQE_MIXED) #define IORING_ENTER_FLAGS (IORING_ENTER_GETEVENTS |\ IORING_ENTER_SQ_WAKEUP |\ @@ -565,17 +566,6 @@ static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) io_req_task_work_add(req); } -/* - * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each - * slot. - */ -static inline size_t uring_sqe_size(struct io_ring_ctx *ctx) -{ - if (ctx->flags & IORING_SETUP_SQE128) - return 2 * sizeof(struct io_uring_sqe); - return sizeof(struct io_uring_sqe); -} - static inline bool io_file_can_poll(struct io_kiocb *req) { if (req->flags & REQ_F_CAN_POLL) |