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Date:   Wed, 19 Apr 2023 09:25:46 +0200
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From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     stable@vger.kernel.org, Mel Gorman <mgorman@techsingularity.net>,
        Jan Kara <jack@suse.cz>, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] rtmutex: Add acquire semantics for rtmutex lock
 acquisition slow path
Message-ID: <20230419072546.gD_YO2-K@linutronix.de>
References: <20230418154315.9PD52J2N@linutronix.de>
 <2023041854-cranium-prone-b9fa@gregkh>
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On 2023-04-18 18:25:48 [+0200], Greg KH wrote:
> > Could this be please backported to 5.15 and earlier? It is already part
> > of the 6.X kernels. I asked about this by the end of January and I'm
> > kindly asking again ;)
> 
> I thought this was only an issues when using the out-of-tree RT patches
> with these kernels, right?  Or is it relevant for 5.15.y from kernel.org
> without anything else?

The out-of-tree RT patches make extensive use of the code. Since it is
upstream code, I assumed it should go via the official stable trees.
Without RT, the code is limited the rt_mutex_lock() used by I2C and the
RCU booster-mutex. 
Since this might not be enough to trigger the problem, let me route this
via rt-stable trees.

> greg k-h

Sebastian