From 24369c2e3bb06d8c4e71fd6ceaf4f8a01ae79b7c Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 28 Jan 2020 03:15:48 +0300 Subject: io_uring: add io-wq workqueue sharing If IORING_SETUP_ATTACH_WQ is set, it expects wq_fd in io_uring_params to be a valid io_uring fd io-wq of which will be shared with the newly created io_uring instance. If the flag is set but it can't share io-wq, it fails. This allows creation of "sibling" io_urings, where we prefer to keep the SQ/CQ private, but want to share the async backend to minimize the amount of overhead associated with having multiple rings that belong to the same backend. Reported-by: Jens Axboe Reported-by: Daurnimator Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 9988e82f858b..e067b92af5ad 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -75,6 +75,7 @@ enum { #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */ #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */ #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */ +#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */ enum { IORING_OP_NOP, @@ -183,7 +184,8 @@ struct io_uring_params { __u32 sq_thread_cpu; __u32 sq_thread_idle; __u32 features; - __u32 resv[4]; + __u32 wq_fd; + __u32 resv[3]; struct io_sqring_offsets sq_off; struct io_cqring_offsets cq_off; }; -- cgit v1.2.3