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Date:   Thu, 7 Nov 2019 11:55:19 -0500
From:   Dennis Zhou <dennis@kernel.org>
To:     Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc:     Dennis Zhou <dennis@kernel.org>, linux-kernel@vger.kernel.org,
        Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@kernel.org>
Subject: Re: [PATCH] percpu-refcount: Use normal instead of RCU-sched"
Message-ID: <20191107165519.GA99408@dennisz-mbp>
References: <20191002112252.ro7wpdylqlrsbamc@linutronix.de>
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 <20191107161749.GA93945@dennisz-mbp>
 <20191107162842.2qgd3db2cjmmsxeh@linutronix.de>
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On Thu, Nov 07, 2019 at 05:28:42PM +0100, Sebastian Andrzej Siewior wrote:
> On 2019-11-07 11:17:49 [-0500], Dennis Zhou wrote:
> > Hello,
> 
> Hi,
> 
> > I just want to clarify a little bit. Is this patch aimed at fixing an
> > issue with RT kernels specifically? 
> 
> Due to the implications of preempt_disable() on RT kernels it fixes
> problems with RT kernels.
> 

Great, do you mind adding this explanation with what the implications
are in the commit message?


> > It'd also be nice to have the
> > numbers as well as if the kernel was RT or non-RT.
> 
> The benchmark was done on a CONFIG_PREEMPT kernel. As said in the commit
> log, the numbers were mostly the same, I can re-run the test and post
> numbers if you want them.
> This patch makes no difference on PREEMPT_NONE or PREEMPT_VOLUNTARY
> kernels.
> 

I think a more explicit explanation in the commit message would suffice.

Thanks,
Dennis