Date:   Tue, 16 Nov 2021 22:02:49 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Joe Korty <joe.korty@concurrent-rt.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Clark Williams <williams@redhat.com>,
        Jun Miao <jun.miao@windriver.com>,
        linux-rt-users <linux-rt-users@vger.kernel.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5.10-rt+] drm/i915/gt: transform irq_disable into
 local_lock.
Message-ID: <20211116210249.t3f6gw56iaow57mq@linutronix.de>
References: <20211007165928.GA43890@zipoli.concurrent-rt.com>
 <20211007171929.hegwwqelf46skjyw@linutronix.de>
 <20211009164908.GA21269@zipoli.concurrent-rt.com>
 <20211116152534.122f8357@gandalf.local.home>
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On 2021-11-16 15:25:34 [-0500], Steven Rostedt wrote:
> I'm looking to see what needs to be added to 5.10-rt. Is there a particular
> fix in one of the 5.x-rt trees (x > 10) that I can pull from? Or is this
> only an issue with 5.10 and below?

I have this:
  https://lore.kernel.org/all/20211026114100.2593433-1-bigeasy@linutronix.de

pending vs upstream and I *think* more than just that one (2/9 from the
series) needs to be backported here. We do have 1/9 differently in 5.10,
not sure about 4/9.
I would love more feedback here from people and I tried to motivate Joe
to provide some. Clark was so nice to test these patches and provide
feedback. My i915 does not trigger all the code paths I'm touching
there.

If you think that 2/9 is obvious enough, please go ahead. If you start
touching that irq_work area then you might also want to pick
  810979682ccc9 ("irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.")
  b4c6f86ec2f64 ("irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT")
  09089db79859c ("irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT")

which made their way into v5.16-rc1.

> -- Steve

Sebastian