From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, [email protected]
Subject: Re: [RFC 5.12] io-wq: cancel unbounded works on io-wq destroy
Date: Fri, 2 Apr 2021 20:19:54 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <932defeefef1b025b22f69f7f420f162460eb842.1617382191.git.asml.silence@gmail.com>
On 4/2/21 10:52 AM, Pavel Begunkov wrote:
> [ 491.222908] INFO: task thread-exit:2490 blocked for more than 122 seconds.
> [ 491.222957] Call Trace:
> [ 491.222967] __schedule+0x36b/0x950
> [ 491.222985] schedule+0x68/0xe0
> [ 491.222994] schedule_timeout+0x209/0x2a0
> [ 491.223003] ? tlb_flush_mmu+0x28/0x140
> [ 491.223013] wait_for_completion+0x8b/0xf0
> [ 491.223023] io_wq_destroy_manager+0x24/0x60
> [ 491.223037] io_wq_put_and_exit+0x18/0x30
> [ 491.223045] io_uring_clean_tctx+0x76/0xa0
> [ 491.223061] __io_uring_files_cancel+0x1b9/0x2e0
> [ 491.223068] ? blk_finish_plug+0x26/0x40
> [ 491.223085] do_exit+0xc0/0xb40
> [ 491.223099] ? syscall_trace_enter.isra.0+0x1a1/0x1e0
> [ 491.223109] __x64_sys_exit+0x1b/0x20
> [ 491.223117] do_syscall_64+0x38/0x50
> [ 491.223131] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 491.223177] INFO: task iou-mgr-2490:2491 blocked for more than 122 seconds.
> [ 491.223194] Call Trace:
> [ 491.223198] __schedule+0x36b/0x950
> [ 491.223206] ? pick_next_task_fair+0xcf/0x3e0
> [ 491.223218] schedule+0x68/0xe0
> [ 491.223225] schedule_timeout+0x209/0x2a0
> [ 491.223236] wait_for_completion+0x8b/0xf0
> [ 491.223246] io_wq_manager+0xf1/0x1d0
> [ 491.223255] ? recalc_sigpending+0x1c/0x60
> [ 491.223265] ? io_wq_cpu_online+0x40/0x40
> [ 491.223272] ret_from_fork+0x22/0x30
>
> Cancel all unbound works on exit, otherwise do_exit() ->
> io_uring_files_cancel() may wait for io-wq destruction for long, e.g.
> until somewhat sends a SIGKILL.
>
> Suggested-by: Jens Axboe <[email protected]>
> Signed-off-by: Pavel Begunkov <[email protected]>
> ---
>
> Not quite happy about it as it cancels pipes and sockets, but
> is probably better than waiting.
I don't think there's any other way, if it's not bounded execution,
we have to cancel it. The same thing would happen these requests
if they were not punted async. It's either this, or "re-parenting"
the requests, if the exiting task is part of a ring that belongs
to a parent.
--
Jens Axboe
prev parent reply other threads:[~2021-04-03 2:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-02 16:52 [RFC 5.12] io-wq: cancel unbounded works on io-wq destroy Pavel Begunkov
2021-04-03 2:19 ` 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