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Message-ID: <c34df726-33df-4188-8010-3b268dfbb607@arm.com>
Date: Mon, 18 Dec 2023 09:19:04 +0100
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Subject: Re: [PATCH 0/4] sched: cpufreq: Remove uclamp max-aggregation
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To: Qais Yousef <qyousef@layalina.io>, Ingo Molnar <mingo@kernel.org>,
 Peter Zijlstra <peterz@infradead.org>, "Rafael J. Wysocki"
 <rafael@kernel.org>, Viresh Kumar <viresh.kumar@linaro.org>,
 Vincent Guittot <vincent.guittot@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
 Lukasz Luba <lukasz.luba@arm.com>, Wei Wang <wvw@google.com>,
 Rick Yiu <rickyiu@google.com>, Chung-Kai Mei <chungkai@google.com>,
 Hongyan Xia <hongyan.xia2@arm.com>
References: <20231208015242.385103-1-qyousef@layalina.io>
From: Dietmar Eggemann <dietmar.eggemann@arm.com>
In-Reply-To: <20231208015242.385103-1-qyousef@layalina.io>
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On 08/12/2023 02:52, Qais Yousef wrote:

[...]

> ===
> 
> This patch is based on remove margins series [1] and data is collected it
> against it as a baseline.
> 
> Testing on pixel 6 with mainline(ish) kernel

How is the Pixel6 configured in terms of per-policy rate_limit_us and
response_time_ms ? Is this the now default 2ms and whatever the systems
calculates for response_time_ms ?

Pixel6 is still a slow switching device, rigth?

root           297     2 1 08:58:01 ?     00:00:13 [sugov:0]
root           298     2 0 08:58:01 ?     00:00:03 [sugov:4]
root           299     2 1 08:58:01 ?     00:00:05 [sugov:6]

> ==
> 
> Speedometer browser benchmark
> 
>        | baseline  | 1.25 headroom |   patch   | patch + 1.25 headroom
> -------+-----------+---------------+-----------+---------------------
> score  |  108.03   |     135.72    |   108.09  |    137.47
> -------+-----------+---------------+-----------+---------------------
> power  |  1204.75  |    1451.79    |  1216.17  |    1484.73
> -------+-----------+---------------+-----------+---------------------

What's the difference between baseline & 1.25 headroom. IMHO, we have:

 static inline unsigned long map_util_perf(unsigned long util)
 {
   return util + (util >> 2);
 }

on baseline?

By patch you refer to the whole patch-set + [1]?

And I assume 'patch + 1.25 headroom' is 'response_time_ms' tuned to
reach 1.25 ?

[...]