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Date: Thu, 30 Oct 2014 15:38:53 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@kernel.dk,
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        mturquette@linaro.org, tuukka.tikkanen@linaro.org,
        nicolas.pitre@linaro.org, patches@linaro.org
Subject: Re: [RFD PATCH 00/10] cpuidle: Predict the next events with the IO
 latencies
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On Wed, Oct 22, 2014 at 03:57:43PM +0200, Daniel Lezcano wrote:
> After discussing at the LPC2014 Dusseldorf, it appears the idea is
> good but the approach is wrong. The latency tracking must be done at
> the device level, per device and not in the task as what is doing this
> patchset.

end_page_writeback()->test_clear_page_writeback()->__bdi_writeout_inc()

Is the IO completion path that has a fair amount of statistics in, maybe
some of that is usable.