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Date: Mon, 8 Apr 2013 14:57:18 +0000
From: Christoph Lameter <cl@linux.com>
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To: Ingo Molnar <mingo@kernel.org>
cc: Frederic Weisbecker <fweisbec@gmail.com>,
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        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 4/4] nohz: New option to force all CPUs in full dynticks
 range
In-Reply-To: <20130330091037.GA31743@gmail.com>
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References: <1364398359-21990-1-git-send-email-fweisbec@gmail.com> <1364398359-21990-5-git-send-email-fweisbec@gmail.com> <20130328074507.GC24433@gmail.com> <CAFTL4hzQfodVP4O+nir1XwQ2QkUUqrfr_dBpWL0635f0u4oRBA@mail.gmail.com>
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I think we could simplify things quite a bit if we either

1. Add any cpus specified with nohz_full/extended=xxx to
rcu_nocb. No check is then necessary anymore.

or

2. Avoid the setting of cpus entirely? If full nohz mode is desired
then pick one cpu (f.e. the first one or the one that is used for xtime
updates) and then make all other cpus nohz. Set the affinity mask for the
rcuoXXX threads to that cpu.

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