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Subject: Re: possible deadlock in console_unlock
To:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
CC:     Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        <linuxarm@huawei.com>, <linux-kernel@vger.kernel.org>
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From:   Yao HongBo <yaohongbo@huawei.com>
Message-ID: <fd3c5c63-912c-a11f-9282-c46211c98521@huawei.com>
Date:   Mon, 18 Feb 2019 20:09:41 +0800
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On 2/18/2019 1:46 PM, Sergey Senozhatsky wrote:
> Hi,
> 
> On (02/16/19 15:59), Yao HongBo wrote:
>>> GFP_NOWARN is probably the best option for now. Yes, it, maybe,
>>> will not work for fault-injection cases; but printk_safe approach
>>> is harder to push for, especially given that printk_safe maybe will
>>> not even exist in the future.
>>
>> I have tried GFP_NOWARN, but the problem still exists.
>> Only print_safe contexts for tty locks can solve the problem.
>> My test scenario is falt-injection.
> 
> Oh, I see. Yes, fault-injection is special.
> 
> I suspect that this patch series can be helpful then
> https://lore.kernel.org/lkml/20181016050428.17966-1-sergey.senozhatsky@gmail.com/T/#u

ok, i'll try it.
Thanks.

> but first we need to figure out if printk_safe will
> stay in the kernel (this will take some time).
> 
> 	-ss
> 
>