This new flag should be set/clear from the application to disable/enable eventfd notifications when a request is completed and queued to the CQ ring.
Before this patch, notifications were always sent if an eventfd is registered, so IORING_CQ_EVENTFD_DISABLED is not set during the initialization. It will be up to the application to set the flag after initialization if no notifications are required at the beginning. Signed-off-by: Stefano Garzarella <[email protected]> --- v1 -> v2: - changed the flag name and behaviour from IORING_CQ_NEED_EVENT to IORING_CQ_EVENTFD_DISABLED [Jens] --- fs/io_uring.c | 2 ++ include/uapi/linux/io_uring.h | 7 +++++++ 2 files changed, 9 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 6e8158269f3c..a9b194e9b5bd 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1152,6 +1152,8 @@ static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) { if (!ctx->cq_ev_fd) return false; + if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) + return false; if (!ctx->eventfd_async) return true; return io_wq_current_is_worker(); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 602bb0ece607..8c5775df08b8 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -209,6 +209,13 @@ struct io_cqring_offsets { __u64 resv2; }; +/* + * cq_ring->flags + */ + +/* disable eventfd notifications */ +#define IORING_CQ_EVENTFD_DISABLED (1U << 0) + /* * io_uring_enter(2) flags */ -- 2.25.4
