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From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Crystal Wood <swood@redhat.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        John Keeping <john@metanate.com>,
        linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: rtmutex, pi_blocked_on, and blk_flush_plug()
Message-ID: <Y+5GScI95xYeQPvf@linutronix.de>
References: <4b4ab374d3e24e6ea8df5cadc4297619a6d945af.camel@redhat.com>
 <Y+47FVJ+hI+NA2In@linutronix.de>
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On 2023-02-16 15:18:03 [+0100], To Crystal Wood wrote:
> On 2023-02-09 22:31:57 [-0600], Crystal Wood wrote:
> > Hello!
Hi,

> - spinlock_t invokes schedule_rtlock() which avoids sched_submit_work().
>   This is the behaviour as with !RT because it spins and does not submit
>   work either.
>   rwlock_t should be have the same way but invokes schedule() instead.
>   This looks wrong. And it could deadlock in sched_submit_work().

I have to correct myself. Also for rwlock_t it uses schedule_rtlock()
which means it does not invoke sched_submit_work().

There there I don't expect any deadlock here.

> > -Crystal

Sebastian