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Subject: Re: [PATCH 3/3] cpuidle/menu: add per cpu pm_qos_resume_latency
 consideration
To: "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
References: <1484227624-6740-1-git-send-email-alex.shi@linaro.org>
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Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
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From: Alex Shi <alex.shi@linaro.org>
Message-ID: <c242e66c-b8d5-fb27-4c54-12c1ef823031@linaro.org>
Date: Fri, 20 Jan 2017 16:35:51 +0800
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On 01/20/2017 05:43 AM, Rafael J. Wysocki wrote:
> The above may be problematic if the constraints change relatively
> often.  It is global and it will affect all of the CPUs in the system
> every time and now think about systems with hundreds of them.

Yes, the disadvantage is waking up all idle cpus when value changed. As
to the multi core concern, maybe a per cpu notifier way is better? But
that's another story of pm_qos...

So Rafael, any comments for this patch version?

Regards
Alex