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From:   "Elliott, Robert (Servers)" <elliott@hpe.com>
To:     Zhen Lei <thunder.leizhen@huawei.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        "Neeraj Upadhyay" <quic_neeraju@quicinc.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        "rcu@vger.kernel.org" <rcu@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v6 1/2] rcu: Add RCU stall diagnosis information
Thread-Topic: [PATCH v6 1/2] rcu: Add RCU stall diagnosis information
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Date:   Wed, 9 Nov 2022 17:03:50 +0000
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 <20221109093739.187-2-thunder.leizhen@huawei.com>
 <MW5PR84MB18423CA291ABCD3DCCE3D416AB3E9@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM>
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> -----Original Message-----
> From: Elliott, Robert (Servers)
> Sent: Wednesday, November 9, 2022 10:56 AM
> > b/Documentation/admin-guide/kernel-parameters.txt
> > index a465d5242774af8..2729f3ad11d108b 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -5082,6 +5082,12 @@
> >  			rcupdate.rcu_cpu_stall_timeout to be used (after
> >  			conversion from seconds to milliseconds).
> >
> > +	rcupdate.rcu_cpu_stall_cputime=3D [KNL]
> > +			Provide statistics on the cputime and count of
> > +			interrupts and tasks during the sampling period. For
> > +			multiple continuous RCU stalls, all sampling periods
> > +			begin at half of the first RCU stall timeout.
>=20
> This description should start with:
>     "In kernels built with CONFIG_RCU_CPU_STALL_TIME=3Dy, "

Please ignore that comment - the module parameter is always
present (only subject to CONFIG_RCU_STALL_COMMON like the others).
The config option is just selecting the default value for
that module parameter.