linux-kernel - Re: [PATCH 5/6] cpuidle: teo: Remove recent intercepts metric

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Message-ID: <a9e06f49-c94c-4f73-a164-0998e78914bb@arm.com>
Date: Fri, 7 Jun 2024 10:26:27 +0100
From: Christian Loehle <christian.loehle@....com>
To: Dietmar Eggemann <dietmar.eggemann@....com>, linux-pm@...r.kernel.org,
 linux-kernel@...r.kernel.org, rafael@...nel.org
Cc: vincent.guittot@...aro.org, qyousef@...alina.io, peterz@...radead.org,
 daniel.lezcano@...aro.org, anna-maria@...utronix.de,
 kajetan.puchalski@....com, lukasz.luba@....com
Subject: Re: [PATCH 5/6] cpuidle: teo: Remove recent intercepts metric

On 6/7/24 09:57, Dietmar Eggemann wrote:
> On 06/06/2024 11:00, Christian Loehle wrote:
>> The logic for recent intercepts didn't work, there is an underflow
>> that can be observed during boot already, which teo usually doesn't
>> recover from, making the entire logic pointless.
> 
> Is this related to:
> 
> https://lkml.kernel.org/r/0ce2d536-1125-4df8-9a5b-0d5e389cd8af@arm.com ?
> 
> In this case, a link here would be helpful to get the story.

It is!
Will include. To my defense, it is included in the cover letter.

> 
>> Furthermore the recent intercepts also were never reset, thus not
>> actually being very 'recent'.
>>
>> If it turns out to be necessary to focus more heavily on resets, the
>> intercepts metric also could be adjusted to decay more quickly.
>>
>> Fixes: 77577558f25d ("cpuidle: teo: Rework most recent idle duration values treatment")
>> Signed-off-by: Christian Loehle <christian.loehle@....com>
> 
> [...]
>