Date: Mon, 9 Sep 2013 06:53:20 -0700
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
        Eric Dumazet <eric.dumazet@gmail.com>, linux-kernel@vger.kernel.org,
        mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
        akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
        josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de,
        rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
        darren@dvhart.com, sbw@mit.edu, cl@linux.com
Subject: Re: [PATCH] rcu: Is it safe to enter an RCU read-side critical
 section?
Message-ID: <20130909135320.GS3966@linux.vnet.ibm.com>
Reply-To: paulmck@linux.vnet.ibm.com
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 <20130906185927.GE2706@somewhere>
 <20130909105347.GK31370@twins.programming.kicks-ass.net>
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On Mon, Sep 09, 2013 at 03:36:04PM +0200, Peter Zijlstra wrote:
> On Mon, Sep 09, 2013 at 06:23:43AM -0700, Paul E. McKenney wrote:
> > And guys, I have to say that the advice on which per-CPU primitive to use
> > varies wildly and randomly.  For all I know, each of you individually
> > might well be sticking to the same story, but taken together, your
> > collective advice is strongly resembling white noise.
> 
> Its partly because cl and I disagree on things. He doesn't seem to care
> much about validation and believes that people will not make mistakes
> with this stuff.

At some point, my only recourse would be to require an Acked-by from one
of you for any per-CPU changes proposed by the other.  I really hope that
it doesn't come to that, but this situation is getting a bit annoying.

> And partly because I didn't get what was going on. While Frederic's
> explanation might be correct it was incomprehensible for me.

And I freely admit that the comments on rcu_is_cpu_idle() are completely
inadequate, and I do apologize for that.  Seemed clear at the time.
But then it always does, doesn't it?  ;-)

							Thanx, Paul

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