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Subject: Re: [QUESTION] Hung task warning while running syzkaller test
To:     Zhihao Cheng <chengzhihao1@huawei.com>,
        LKML <linux-kernel@vger.kernel.org>, peterz@infradead.org,
        Ingo Molnar <mingo@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        patrick.bellasi@arm.com, tglx@linutronix.de
Cc:     Kefeng Wang <wangkefeng.wang@huawei.com>,
        "zhangyi (F)" <yi.zhang@huawei.com>
References: <0d7aa66d-d2b9-775c-56b3-543d132fdb84@huawei.com>
 <1693d19e-56c7-9d6f-8e80-10fe82101cff@arm.com>
 <aa5d0f35-e707-f5e3-251e-f940c0b0232b@huawei.com>
 <4ca01869-7997-cfce-edce-e75337d3a6fa@arm.com>
 <abba880d-cfa6-3485-7831-9998db290396@huawei.com>
From:   Valentin Schneider <valentin.schneider@arm.com>
Message-ID: <d7e9f62e-d7a6-50ec-6fb5-76ad136506df@arm.com>
Date:   Mon, 28 Oct 2019 18:54:22 +0100
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On 26/10/2019 03:48, Zhihao Cheng wrote:> 3. You can convert the repro file into a C program by 'syzprog' tool(see syzprog.c). Using compiled syzprog.c directly for testing did not show hung task, which confused me.
> 

Good to know that you can get a readable program out of this, but that diff
in behaviour isn't reassuring.

Also, I don't see anything in there that would try to play with cgroups - I
was mostly curious about the use of the freezer, but don't see any in the
C code. Out of curiosity I ran a similar kernel that I tried before (without
the right configs), and it doesn't complain about missing cgroup options...