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From: John Ogness <john.ogness@linutronix.de>
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To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>, Derek Barbosa
 <debarbos@redhat.com>
Cc: pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org,
 linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org,
 williams@redhat.com, jlelli@redhat.com, ahalaney@redhat.com,
 lgoncalv@redhat.com, jwyatt@redhat.com, aubaker@redhat.com
Subject: Re: [PATCH] prinkt/nbcon: Add a scheduling point to
 nbcon_kthread_func().
In-Reply-To: <20240620094300.YJlW043f@linutronix.de>
References: <ZnHF5j1DUDjN1kkq@debarbos-thinkpadt14sgen2i.remote.csb>
 <20240620071545.Es9LoyJY@linutronix.de>
 <20240620093246.HE9XDWSZ@linutronix.de>
 <20240620094300.YJlW043f@linutronix.de>
Date: Fri, 21 Jun 2024 03:22:49 +0206
Message-ID: <874j9n5c3i.fsf@jogness.linutronix.de>
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On 2024-06-20, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> Constant printing can lead to a CPU hog in nbcon_kthread_func(). The
> context is preemptible but on !PREEMPT kernels there is no explicit
> preemption point which leads softlockup warnings.
>
> Add an explicit preemption point in nbcon_kthread_func().
>
> Reported-by: Derek Barbosa <debarbos@redhat.com>
> Link: https://lore.kernel.org/ZnHF5j1DUDjN1kkq@debarbos-thinkpadt14sgen2i.remote.csb
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Reviewed-by: John Ogness <john.ogness@linutronix.de>