From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, [email protected]
Subject: Re: [PATCH 0/5] fixes for REQ_F_COMP_LOCKED
Date: Tue, 13 Oct 2020 08:57:51 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 10/13/20 3:46 AM, Pavel Begunkov wrote:
> On 13/10/2020 09:43, Pavel Begunkov wrote:
>> This removes REQ_F_COMP_LOCKED to fix a couple of problems with it.
>>
>> [5/5] is harsh and some work should be done to ease the aftermath,
>> i.e. io_submit_flush_completions() and maybe fail_links().
>>
>> Another way around would be to replace the flag with an comp_locked
>> argument in put_req(), free_req() and so on, but IMHO in a long run
>> removing it should be better.
>>
>> note: there is a new io_req_task_work_add() call in [5/5]. Jens,
>> could you please verify whether passed @twa_signal_ok=true is ok,
>> because I don't really understand the difference.
It should be fine, the only case that can't use 'true' is when it's
called from within the waitqueue handler as we can recurse on that
lock.
Luckily that'll all go away once the TWA_SIGNAL improvement patches
are ready.
> btw, when I copied task_work_add(TWA_RESUME) from __io_free_req(),
> tasks were hanging sleeping uninterruptibly, and fail_links()
> wasn't waking them. It looks like the deferring branch of
> __io_free_req() is buggy as well and should use
> io_req_task_work_add().
Probably related to exit conditions.
--
Jens Axboe
next prev parent reply other threads:[~2020-10-13 14:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-13 8:43 [PATCH 0/5] fixes for REQ_F_COMP_LOCKED Pavel Begunkov
2020-10-13 8:43 ` [PATCH 1/5] io_uring: don't set COMP_LOCKED if won't put Pavel Begunkov
2020-10-13 8:43 ` [PATCH 2/5] io_uring: don't unnecessarily clear F_LINK_TIMEOUT Pavel Begunkov
2020-10-13 8:43 ` [PATCH 3/5] io_uring: don't put a poll req under spinlock Pavel Begunkov
2020-10-13 14:54 ` Jens Axboe
2020-10-13 8:43 ` [PATCH 4/5] io_uring: dig out COMP_LOCK from deep call chain Pavel Begunkov
2020-10-13 8:44 ` [PATCH 5/5] io_uring: fix REQ_F_COMP_LOCKED by killing it Pavel Begunkov
2020-10-13 9:46 ` [PATCH 0/5] fixes for REQ_F_COMP_LOCKED Pavel Begunkov
2020-10-13 14:57 ` Jens Axboe [this message]
2020-10-13 17:02 ` Pavel Begunkov
2020-10-13 15:14 ` Jens Axboe
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