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Date:   Mon, 19 Apr 2021 09:45:42 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     =?utf-8?B?5ZGo5Lyg6auY?= <zhouchuangao@vivo.com>
Cc:     Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Michal Hocko <mhocko@suse.com>,
        "Guilherme G. Piccoli" <gpiccoli@canonical.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Lukas Bulwahn <lukas.bulwahn@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: Re: Re: [PATCH] kernel/hung_task: Add a whitelist and blacklist
 mechanism.
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On Mon, Apr 19, 2021 at 09:46:26AM +0800, 周传高 wrote:
> 
> >On Sat, Apr 17, 2021 at 07:13:01AM -0700, zhouchuangao wrote:
> >> eg:
> >> In Android system, we usually and some processes to the whitelist.
> >> static task_t task_whitelist[] = {
> >> 	{"mdrt_thread", HUNG_TASK_WHITELIST},
> >> 	{"chre_kthread", HUNG_TASK_WHITELIST},
> >> 	{"scp_power_reset", HUNG_TASK_WHITELIST},
> >> 	{"ccci_fsm1", HUNG_TASK_WHITELIST},
> >> 	{"qos_ipi_recv", HUNG_TASK_WHITELIST},
> >> 	{NULL, 0},
> >> };
> >
> >What are these tasks doing that the hung-task detector fires on them?
> >Should you fix that instead?
> 
> These tasks are implemented by the SoC vendor, and normally they do
> not configure HUNG TASK, so we need to ignore these tasks if we use
> HUNG TASK. 

Then raise a bug against their crap software, don't try and work around
it in the kernel.

We're not going to upstream workarounds for crap vendor software.