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Date: Wed, 16 Aug 2017 12:41:40 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
        Pratyush Anand <panand@redhat.com>,
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        john.stultz@linaro.org, linux-kernel@vger.kernel.org
Subject: Re: RCU stall when using function_graph
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On Wed, 16 Aug 2017 09:32:28 -0700
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:

> Let me see if I understand you...  About halfway to the stall limit,
> RCU triggers an irq_work (on each CPU that has not yet passed through
> a quiescent state, IPIing them in turn?), and if the irq_work has
> not completed by the end of the stall limit, RCU adds that to its
> stall-warning message.

Doesn't even have to be half way through. It could be done at the
limit, and then wait a little more.

> 
> Or am I missing something here?

No, I think that's what I was suggesting.

-- Steve