From 83bfc0c6b620fd4d5e69cb6fca1eb3fda9eaa1ef Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 14 Apr 2022 11:22:51 -0600 Subject: [PATCH] man/io_uring_setup.2: document recent FEAT flag additions The man page was missing IORING_FEAT_CQE_SKIP and IORING_FEAT_LINKED_FILE, add an explanation for them. Signed-off-by: Jens Axboe --- man/io_uring_setup.2 | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/man/io_uring_setup.2 b/man/io_uring_setup.2 index c54c5da5..f3911afa 100644 --- a/man/io_uring_setup.2 +++ b/man/io_uring_setup.2 @@ -337,6 +337,25 @@ If this flag is set, then io_uring supports a variety of features related to fixed files and buffers. In particular, it indicates that registered buffers can be updated in-place, whereas before the full set would have to be unregistered first. Available since kernel 5.13. +.TP +.B IORING_FEAT_CQE_SKIP +If this flag is set, then io_uring supports setting +.B IOSQE_CQE_SKIP_SUCCESS +in the submitted SQE, indicating that no CQE should be generated for this +SQE if it executes normally. If an error happens processing the SQE, a +CQE with the appropriate error value will still be generated. Available since +kernel 5.17. +.TP +.B IORING_FEAT_LINKED_FILE +If this flag is set, then io_uring supports sane assignment of files for SQEs +that have dependencies. For example, if a chain of SQEs are submitted with +.B IOSQE_IO_LINK, +then kernels without this flag will prepare the file for each link upfront. +If a previous link opens a file with a known index, eg if direct descriptors +are used with open or accept, then file assignment needs to happen post +execution of that SQE. If this flag is set, then the kernel will defer +file assignment until execution of a given request is started. Available since +kernel 5.17. .PP The rest of the fields in the