public inbox for [email protected]
 help / color / mirror / Atom feed
* [PATCH liburing 1/1] man/io_uring_setup.2: document IORING_SETUP_SINGLE_ISSUER
@ 2022-07-22 11:49 Pavel Begunkov
  2022-07-22 15:21 ` Jens Axboe
  0 siblings, 1 reply; 2+ messages in thread
From: Pavel Begunkov @ 2022-07-22 11:49 UTC (permalink / raw)
  To: io-uring; +Cc: Jens Axboe, asml.silence

Signed-off-by: Pavel Begunkov <[email protected]>
---
 man/io_uring_setup.2 | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/man/io_uring_setup.2 b/man/io_uring_setup.2
index 75c69ff..0f57d8f 100644
--- a/man/io_uring_setup.2
+++ b/man/io_uring_setup.2
@@ -239,6 +239,24 @@ variant. This is a requirement for using certain request types, as of 5.19
 only the
 .B IORING_OP_URING_CMD
 passthrough command for NVMe passthrough needs this. Available since 5.19.
+.TP
+.B IORING_SETUP_SINGLE_ISSUER
+A hint to the kernel that only a single task can submit requests, which is used
+for internal optimisations. The kernel enforces the rule, which only affects
+.I
+io_uring_enter(2)
+calls submitting requests and will fail them with
+.B -EEXIST
+if the restriction is violated.
+The submitter task may differ from the task that created the ring.
+Note that when
+.B IORING_SETUP_SQPOLL
+is set it is considered that the polling task is doing all submissions
+on behalf of the userspace and so it always complies with the rule disregarding
+how many userspace tasks do
+.I
+io_uring_enter(2).
+Available since 5.20.
 .PP
 If no flags are specified, the io_uring instance is setup for
 interrupt driven I/O.  I/O may be submitted using
-- 
2.37.0


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH liburing 1/1] man/io_uring_setup.2: document IORING_SETUP_SINGLE_ISSUER
  2022-07-22 11:49 [PATCH liburing 1/1] man/io_uring_setup.2: document IORING_SETUP_SINGLE_ISSUER Pavel Begunkov
@ 2022-07-22 15:21 ` Jens Axboe
  0 siblings, 0 replies; 2+ messages in thread
From: Jens Axboe @ 2022-07-22 15:21 UTC (permalink / raw)
  To: io-uring, asml.silence

On Fri, 22 Jul 2022 12:49:02 +0100, Pavel Begunkov wrote:
> 


Applied, thanks!

[1/1] man/io_uring_setup.2: document IORING_SETUP_SINGLE_ISSUER
      commit: 02adcf497c9f4ca20175b291f8269faff4da958c

Best regards,
-- 
Jens Axboe



^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2022-07-22 15:21 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-07-22 11:49 [PATCH liburing 1/1] man/io_uring_setup.2: document IORING_SETUP_SINGLE_ISSUER Pavel Begunkov
2022-07-22 15:21 ` Jens Axboe

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox