Based on an explanation from the Linux kernel upstream commit:

  07754bfd9aee ("io_uring: enable toggle of iowait usage when waiting on CQEs")

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 man/io_uring_enter.2 | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/man/io_uring_enter.2 b/man/io_uring_enter.2
index 99c0ab222675..a054a7cdfbd4 100644
--- a/man/io_uring_enter.2
+++ b/man/io_uring_enter.2
@@ -134,7 +134,21 @@ but merely an offset into an area of wait regions previously registered with
 .BR io_uring_register (2)
 using the
 .B IORING_REGISTER_MEM_REGION
-operation. Available since 6.13
+operation.
+
+Available since 6.13
+
+.TP
+.B IORING_ENTER_NO_IOWAIT
+When this flag is set, the system call will not mark the waiting task as being
+in iowait if it is sleeping waiting on events and there are pending requests.
+This is useful if iowait isn't expected when waiting for events. It can also
+prevent extra power usage by allowing the CPU to enter lower sleep states.
+This flag is only available if the kernel supports the
+.B IORING_FEAT_NO_IOWAIT
+feature.
+
+Available since 6.15.
 
 .PP
 .PP
-- 
Ammar Faizi