linux-kernel - Re: [PATCH 1/3] cpuidle/menu: stop seeking deeper idle if current state is too deep

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Message-ID: <a0804d15-c048-1de1-e30a-a1bbeb45c5a9@linux.intel.com>
Date:   Thu, 5 Jan 2017 07:55:24 -0800
From:   Arjan van de Ven <arjan@...ux.intel.com>
To:     Rik van Riel <riel@...hat.com>, Alex Shi <alex.shi@...aro.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        vincent.guittot@...aro.org,
        open list <linux-kernel@...r.kernel.org>
Cc:     linux-pm@...r.kernel.org, Ulf Hansson <ulf.hansson@...aro.org>,
        Rasmus Villemoes <linux@...musvillemoes.dk>
Subject: Re: [PATCH 1/3] cpuidle/menu: stop seeking deeper idle if current
 state is too deep

On 1/5/2017 7:43 AM, Rik van Riel wrote:
> On Thu, 2017-01-05 at 23:29 +0800, Alex Shi wrote:
>> The obsolete commit 71abbbf85 want to introduce a dynamic cstates,
>> but it was removed for long time. Just left the nonsense deeper
>> cstate
>> checking.
>>
>> Since all target_residency and exit_latency are going longer in
>> deeper
>> idle state, no needs to waste some cpu cycle on useless seeking.
>
> Makes me wonder if it would be worth documenting the
> requirement that c-states be listed in increasing
> order?

or better, a boot time quick check...