From 15739afc53919cded39330aace2fa75bdb2abc60 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 15 Jul 2019 16:10:38 -0600 Subject: man: add IOSQE_IO_DRAIN and IOSQE_IO_LINK Add descriptions of these SQE flags. Signed-off-by: Jens Axboe --- man/io_uring_enter.2 | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/man/io_uring_enter.2 b/man/io_uring_enter.2 index 344d212..bb2d5a2 100644 --- a/man/io_uring_enter.2 +++ b/man/io_uring_enter.2 @@ -197,8 +197,9 @@ will contain .PP The .I flags -field is a bit mask. Currently, the only supported flag is -.B IOSQE_FIXED_FILE. +field is a bit mask. The supported flags are: +.TP +.B IOSQE_FIXED_FILE When this flag is specified, .I fd is an index into the files array registered with the io_uring instance (see the @@ -206,7 +207,22 @@ is an index into the files array registered with the io_uring instance (see the section of the .BR io_uring_register (2) man page). - +.TP +.B IOSQE_IO_DRAIN +When this flag is specified, the SQE will not be started before previously +submitted SQEs have completed, and new SQEs will not be started before this +one completes. +.TP +.B IOSQE_IO_LINK +When this flag is specified, it forms a link with the next SQE in the +submission ring. That next SQE will not be started before this one completes. +This, in effect, forms a chain of SQEs, which can be arbitrarily long. The tail +of the chain is denoted by the first SQE that does not have this flag set. +This flag has no effect on previous SQE submissions, nor does it impact SQEs +that are outside of the chain tail. This means that multiple chains can be +executing in parallel, or chains and individual SQEs. Only members inside the +chain are serialized. +.PP .I ioprio specifies the I/O priority. See .BR ioprio_get (2) -- cgit