MIME-Version: 1.0
In-Reply-To: <CANaxB-xu5cD3SFU1sq_7Y7yUOpcNDTd_8pgPvc8TuTb+5ABYFA@mail.gmail.com>
References: <CANaxB-zEpB26kNRdthoZjz04ZQmXycByK8hRfQDes+K1i0_eJw@mail.gmail.com>
	<5584422A.8050009@kernel.dk>
	<CANaxB-xu5cD3SFU1sq_7Y7yUOpcNDTd_8pgPvc8TuTb+5ABYFA@mail.gmail.com>
Date: Mon, 22 Jun 2015 23:13:28 +0300
Message-ID: <CANaxB-zcgRAzFroh_PBzHCo5MPwdej79S6KeFc8CkisVPmLbsA@mail.gmail.com>
Subject: Re: linux-next: BUG: unable to handle kernel NULL pointer dereference
 in cfq_print_leaf_weight()
From: Andrey Wagin <avagin@gmail.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Arianna Avanzini <avanzini.arianna@gmail.com>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1150
Lines: 33

2015-06-19 23:26 GMT+03:00 Andrey Wagin <avagin@gmail.com>:
> 2015-06-19 19:24 GMT+03:00 Jens Axboe <axboe@kernel.dk>:
>> On 06/17/2015 03:55 PM, Andrey Wagin wrote:
>>>
>>> Hi All,
>>>
>>> I executed CRIU tests on the 4.1.0-rc8-next-20150617 kernel and met
>>> this bug. Maybe it will be interested for someone to look at it.
>>
>>
>> This should fix it:
>>
>> http://git.kernel.dk/cgit/linux-block/commit/?h=for-4.2/core&id=9470e4a693db84bee7becbba8de01af02bb23c9f
>
> Hi Jens,
>
> Thank you for the path. I think we need to fix __cfq_set_weight and
> __cfq_set_weight_device too.

I've seen that you fixed these functions too. But CRIU tests still
fail, because they tries to restore a value of blkio.weight and get
EINVAL. It works fine on the upstream kernel.

For me the suggested interface looks weird. What if a device which
uses cfq isn't permanent. If I detach the device, cgroup configuration
will be destroyed and then if I attach the device again, I will need
to apply cgroup parameters again.

Thanks,
Andrew
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at  http://www.tux.org/lkml/