From: Jens Axboe <axboe@kernel.dk>
To: Ju Hyung Park <qkrwngud825@gmail.com>, io-uring@vger.kernel.org
Subject: Re: io_uring possibly the culprit for qemu hang (linux-5.4.y)
Date: Wed, 30 Sep 2020 21:03:20 -0600 [thread overview]
Message-ID: <8de3b94a-042a-4b64-0458-e827ec5695d6@kernel.dk> (raw)
In-Reply-To: <CAD14+f3G2f4QEK+AQaEjAG4syUOK-9bDagXa8D=RxdFWdoi5fQ@mail.gmail.com>
On 9/30/20 10:26 AM, Ju Hyung Park wrote:
> Hi everyone.
>
> I have recently switched to a setup running QEMU 5.0(which supports
> io_uring) for a Windows 10 guest on Linux v5.4.63.
> The QEMU hosts /dev/nvme0n1p3 to the guest with virtio-blk with
> discard/unmap enabled.
>
> I've been having a weird issue where the system would randomly hang
> whenever I turn on or shutdown the guest. The host will stay up for a
> bit and then just hang. No response on SSH, etc. Even ping doesn't
> work.
>
> It's been hard to even get a log to debug the issue, but I've been
> able to get a show-backtrace-all-active-cpus sysrq dmesg on the most
> recent encounter with the issue and it's showing some io_uring
> functions.
>
> Since I've been encountering the issue ever since I switched to QEMU
> 5.0, I suspect io_uring may be the culprit to the issue.
>
> While I'd love to try out the mainline kernel, it's currently not
> feasible at the moment as I have to stay in linux-5.4.y. Backporting
> mainline's io_uring also seems to be a non-trivial job.
>
> Any tips would be appreciated. I can build my own kernel and I'm
> willing to try out (backported) patches.
I'll see if I can reproduce this, thanks for the report!
--
Jens Axboe
next prev parent reply other threads:[~2020-10-01 3:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 16:26 io_uring possibly the culprit for qemu hang (linux-5.4.y) Ju Hyung Park
2020-10-01 3:03 ` Jens Axboe [this message]
2020-10-01 8:59 ` Stefano Garzarella
2020-10-01 13:47 ` Jack Wang
2020-10-01 14:30 ` Ju Hyung Park
2020-10-02 7:34 ` Stefano Garzarella
2020-10-16 18:04 ` Ju Hyung Park
2020-10-16 18:07 ` Jens Axboe
2020-10-17 14:29 ` Ju Hyung Park
2020-10-17 15:02 ` Jens Axboe
2020-10-19 9:22 ` Pankaj Gupta
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