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Date:   Fri, 14 Jul 2023 10:56:15 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Gao Xiang <hsiangkao@linux.alibaba.com>
Cc:     Joel Fernandes <joel@joelfernandes.org>, paulmck@kernel.org,
        Sandeep Dhavale <dhavale@google.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Zqiang <qiang.zhang1211@gmail.com>,
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        <angelogioacchino.delregno@collabora.com>,
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Subject: Re: [PATCH v1] rcu: Fix and improve RCU read lock checks when
 !CONFIG_DEBUG_LOCK_ALLOC
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On Fri, 14 Jul 2023 21:51:16 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> >> we need to work on
> >> CONFIG_PREEMPT_COUNT=n (why not?), we could just always trigger a
> >> workqueue for this.
> >>  
> > 
> > So CONFIG_PREEMPT_COUNT=n users don't deserve good performance? ;-)  
> 
> I'm not sure if non-preemptible kernel users really care about
> such sensitive latencies, I don't know, my 2 cents.

CONFIG_PREEMPT_COUNT=n is for *performance* but not for *latency*. That is,
they care about the overall performance (batch processing) but not
interactive performance.

-- Steve