public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Alexander Babayants <[email protected]>,
	[email protected]
Subject: Re: Submitting IO events with IORING_FEAT_NODROP and overflown CQ ring
Date: Sun, 5 May 2024 12:11:13 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAB92dJbb3aMD14sHwQGDQYofj3H5hH84QTXuzQZ44TZQp0j1Ew@mail.gmail.com>

On 5/3/24 5:21 PM, Alexander Babayants wrote:
> Hi!
> 
> Per io_uring_setup(2):
> 
>> IORING_FEAT_NODROP
> ...
>> If this overflow condition is entered,
>> attempting to submit more IO will fail with the -EBUSY
>> error value, if it can't flush the overflown events to the
>> CQ ring. If this happens, the application must reap events
>> from the CQ ring and attempt the submit again.
> 
> But I'm not getting -EBUSY on a 6.2 kernel when submitting to the ring
> with a full CQ ring and an overflow flag set. I'm not an expert in
> uring code, but it seems the error was removed in commit
> 1b346e4aa8e79227391ffd6b7c6ee5acf0fa8bfc. Could you please check if
> I'm right and if that change was intentional?

This is correct and intentional. The man page should get updated with a
note on the current behavior.

-- 
Jens Axboe


      reply	other threads:[~2024-05-05 18:11 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-03 23:21 Submitting IO events with IORING_FEAT_NODROP and overflown CQ ring Alexander Babayants
2024-05-05 18:11 ` Jens Axboe [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox