From: Pavel Begunkov <[email protected]>
To: Victor Stewart <[email protected]>
Cc: io-uring <[email protected]>
Subject: Re: bug with fastpoll accept and sqpoll + IOSQE_FIXED_FILE
Date: Tue, 2 Feb 2021 17:21:52 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAM1kxwj6Cdqi0hJFNtGFvK=g=KoNRPMmLVoxtahFKZsjOkcTKQ@mail.gmail.com>
On 02/02/2021 16:18, Victor Stewart wrote:
>>> Please don't forget about checking error codes. At least fixed
>>> files don't work for you because of
>>>
>>> int fds[10];
>>> memset(fds, -1, 10); // 10 bytes, not 10 ints
>>>
>>> So io_uring_register_files() silently fails.
>
> well i'm glad this one was my own careless error. fresh eyes are
> everything. you're right, bad habit of ignoring return values lol.
>
>> Also you forget to submit, all works with these 2 changes.
>>
>> When you don't do io_uring_submit(), apparently it gets live-locked
>> in liburing's _io_uring_get_cqe(), that's a bug.
>
> in the comments above io_uring_wait_cqe_timeout it says it submits for
> you, that's why i didn't submit here. but i guess great if that
There is a change of behaviour, if IORING_FEAT_EXT_ARG is set it
won't submit (IIRC, since 5.12) -- it's pretty important for some
multi-threaded cases.
So... where in particular does it say that? In case your liburing
is up to date and we forgot to remove such a comment.
> exposed the _io_uring_get_cqe bug.
It's great for sure!
>
> thanks so much for taking a look at this Pavel
>
--
Pavel Begunkov
next prev parent reply other threads:[~2021-02-02 17:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 5:36 bug with fastpoll accept and sqpoll + IOSQE_FIXED_FILE Victor Stewart
2021-02-02 11:05 ` Pavel Begunkov
2021-02-02 11:23 ` Pavel Begunkov
2021-02-02 16:18 ` Victor Stewart
2021-02-02 16:30 ` Victor Stewart
2021-02-02 16:44 ` Jens Axboe
2021-02-02 17:10 ` Victor Stewart
2021-02-02 17:24 ` Jens Axboe
2021-02-02 17:41 ` Pavel Begunkov
2021-02-02 20:34 ` Pavel Begunkov
2021-02-02 20:48 ` Jens Axboe
2021-02-02 20:56 ` Pavel Begunkov
2021-02-03 11:49 ` Pavel Begunkov
2021-02-04 16:50 ` Jens Axboe
2021-02-05 12:46 ` Pavel Begunkov
2021-02-05 14:42 ` Jens Axboe
2021-02-05 14:49 ` Pavel Begunkov
2021-02-02 17:46 ` Jens Axboe
2021-02-02 17:50 ` Victor Stewart
2021-02-02 17:57 ` Jens Axboe
2021-02-02 17:46 ` Victor Stewart
2021-02-02 17:21 ` Pavel Begunkov [this message]
2021-02-02 17:30 ` Victor Stewart
2021-02-02 17:45 ` Victor Stewart
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