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Date: Wed, 12 Nov 2014 20:26:05 +0530
Message-ID: <CAKohpo=U7K==YMytwcGwteTXdf1RFdxo8BoDhfR-9AriL83D8Q@mail.gmail.com>
Subject: Re: Future of NOHZ full/isolation development (was Re: [NOHZ] Remove scheduler_tick_max_deferment)
From: Viresh Kumar <viresh.kumar@linaro.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Lameter <cl@linux.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Gilad Ben-Yossef <gilad@benyossef.com>, Tejun Heo <tj@kernel.org>,
        John Stultz <john.stultz@linaro.org>,
        Mike Frysinger <vapier@gentoo.org>,
        Minchan Kim <minchan.kim@gmail.com>,
        Hakan Akkan <hakanakkan@gmail.com>,
        Max Krasnyansky <maxk@qti.qualcomm.com>,
        Hugh Dickins <hughd@google.com>, "H. Peter Anvin" <hpa@zytor.com>,
        Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
        Kevin Hilman <khilman@linaro.org>
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On 12 November 2014 19:24, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> I'd rather leave that to tracepoints. Like trace_hrtimer_spurious().

Yeah, it was just to prove things right on the console without getting
into traces.

> Or better yet: have trace_hrtimer_interrupt() which we can compare against
> trace_hrtimer_expire_entry/exit() to check if any hrtimer callback have run
> in the interrupt. This way we avoid workarounds like the above count.

Yeah, I also believe we better add this debug information to mainline kernel.
I will try to get a patch for that soon.

Would it be recommended to add both trace points?
i.e. trace_hrtimer_interrupt() and trace_hrtimer_spurious() ?

--
viresh
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