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Subject: Re: [syzbot] INFO: rcu detected stall in tctx_task_work
To:     syzbot <syzbot+e4f5deeeccdd5a4873fe@syzkaller.appspotmail.com>,
        asml.silence@gmail.com, fweisbec@gmail.com,
        io-uring@vger.kernel.org, linux-kernel@vger.kernel.org,
        mingo@kernel.org, syzkaller-bugs@googlegroups.com,
        tglx@linutronix.de, xiaoguang.wang@linux.alibaba.com
References: <00000000000030c35005cfa98ed5@google.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <13c4d07e-0e4c-ee55-c3be-1b42125f248d@kernel.dk>
Date:   Sun, 31 Oct 2021 13:40:48 -0600
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On 10/31/21 11:40 AM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    bdcc9f6a5682 Add linux-next specific files for 20211029
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=10be38f4b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=4b504bcb4c507265
> dashboard link: https://syzkaller.appspot.com/bug?extid=e4f5deeeccdd5a4873fe
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10b915d4b00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1395f3e2b00000
> 
> The issue was bisected to:
> 
> commit 34ced75ca1f63fac6148497971212583aa0f7a87
> Author: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
> Date:   Mon Oct 25 05:38:48 2021 +0000
> 
>     io_uring: reduce frequent add_wait_queue() overhead for multi-shot poll request

This was dropped from the tree last week:

#syz invalid

-- 
Jens Axboe