Date: Fri, 28 Oct 2016 09:38:04 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Vikram Mulukutla <markivx@codeaurora.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
        Srivatsa Vaddagiri <vatsa@codeaurora.org>,
        Steve Muckle <steve.muckle@linaro.org>,
        Olav Haugan <ohaugan@codeaurora.org>,
        Syed Rameez Mustafa <rameezmustafa@codeaurora.org>,
        Joonwoo Park <joonwoop@codeaurora.org>,
        Pavankumar Kondeti <pkondeti@codeaurora.org>,
        Saravana Kannan <skannan@codeaurora.org>,
        Bryan Huntsman <bryanh@codeaurora.org>,
        Juri Lelli <juri.lelli@arm.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Chris Redpath <chris.redpath@arm.com>,
        Robin Randhawa <robin.randhawa@arm.com>,
        Patrick Bellasi <patrick.bellasi@arm.com>,
        Todd Kjos <tkjos@google.com>, Srinath Sridharan <srinathsr@google.com>,
        Andres Oportus <andresoportus@google.com>,
        Leo Yan <leo.yan@linaro.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Vikram Mulukutla <markivx@codeauorora.org>
Subject: Re: [RFC PATCH 2/3] sched: Introduce Window-Assisted CPU utilization
 Tracking
Message-ID: <20161028073804.GR3102@twins.programming.kicks-ass.net>
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On Fri, Oct 28, 2016 at 12:10:41AM -0700, Vikram Mulukutla wrote:
> +static int cpu_is_waiting_on_io(struct rq *rq)
> +{
> +	if (!walt_io_is_busy)
> +		return 0;
> +
> +	return atomic_read(&rq->nr_iowait);
> +}

This is just drug induced nonsense. The per-cpu nr_iowait number is
completely without meaning.