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Subject: Re: [PATCH] hung_task: recover hung task warnings in next check
 interval
To:     Yafang Shao <laoar.shao@gmail.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Dmitry Vyukov <dvyukov@google.com>,
        LKML <linux-kernel@vger.kernel.org>
References: <1561010100-14080-1-git-send-email-laoar.shao@gmail.com>
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 <CALOAHbCe9J0pOCW03dW+C4NK__amTKttAs=eNHXwvPPf5Lpwhw@mail.gmail.com>
From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <ac52f383-697d-8102-a6af-6aa172ee2a6f@i-love.sakura.ne.jp>
Date:   Thu, 20 Jun 2019 19:23:11 +0900
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On 2019/06/20 19:10, Yafang Shao wrote:
>>> With this patch, hung task warnings will be reset with
>>> sys_hung_task_warnings setting in evenry check interval.
>>
>> Since it is uncommon that the messages are printed for more than 10
>> times for one check_hung_uninterruptible_tasks() call, this patch is
>> effectively changing to always print the messages (in other words,
>> setting -1).
> 
> If sys_hung_task_warnings can't be recovered, does it make sense to exist?
> In which case do we need this setting ?

Someone might want to print the messages up to only a few times because he/she
does not like the ever-repeating messages. But automatically resetting will
forbid his/her wish to print the messages for up to only a few times.

> 
> Btw, why the default value of this setting is 10, instead of -1 ?

I don't know. I guess just by historical reason, for this variable
has been existed before support of -1 is added.