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From: Qais Yousef <qyousef@layalina.io>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	Lukasz Luba <lukasz.luba@arm.com>
Subject: Re: [RFC PATCH 0/7] sched: cpufreq: Remove magic margins
Date: Sun, 10 Sep 2023 22:17:10 +0100	[thread overview]
Message-ID: <20230910211710.a367up7rstm2l7zr@airbuntu> (raw)
In-Reply-To: <20230908133336.uge4hcnx4cum3lg5@airbuntu>

On 09/08/23 14:33, Qais Yousef wrote:
> On 09/08/23 12:25, Peter Zijlstra wrote:
> > On Fri, Sep 08, 2023 at 01:17:25AM +0100, Qais Yousef wrote:
> > 
> > > Just to be clear, my main issue here with the current hardcoded values of the
> > > 'margins'. And the fact they go too fast is my main problem.
> > 
> > So I stripped the whole margin thing from my reply because I didn't want
> > to comment on that yet, but yes, I can see how those might be a problem,
> > and you're changing them into something dynamic, not just removing them.
> 
> The main difficulty is that if you try to apply those patches on their own, I'm
> sure you'll notice a difference. So if we were to take this alone and put them
> on linux-next; I expect a few regression reports for those who run with
> schedutil. Any ST oriented workload will not be happy. But if we compensate to
> reduce the regression, my problem will re-appear, just for a different reason.
> So whack-a-mole.

Sorry I just realized that the dynamic thing was about the margin, not the new
knob.

My answer above still holds to some extent. But yes, I meant to write that I'm
removing magic hardcoded numbers from the margins.


Cheers

--
Qais Yousef

      parent reply	other threads:[~2023-09-10 21:17 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-27 23:31 [RFC PATCH 0/7] sched: cpufreq: Remove magic margins Qais Yousef
2023-08-27 23:31 ` [RFC PATCH 1/7] sched/pelt: Add a new function to approximate the future util_avg value Qais Yousef
2023-09-06 12:56   ` Dietmar Eggemann
2023-09-06 21:19     ` Qais Yousef
2023-09-07 11:12       ` Dietmar Eggemann
2023-09-10 19:58         ` Qais Yousef
2023-09-13 17:22           ` Dietmar Eggemann
2023-09-16 19:49             ` Qais Yousef
2023-09-16 19:52               ` Qais Yousef
2023-08-27 23:31 ` [RFC PATCH 2/7] sched/pelt: Add a new function to approximate runtime to reach given util Qais Yousef
2023-09-06 12:56   ` Dietmar Eggemann
2023-09-06 20:44     ` Dietmar Eggemann
2023-09-06 21:38       ` Qais Yousef
2023-09-15  9:15   ` Hongyan Xia
2023-09-16 19:56     ` Qais Yousef
2023-08-27 23:31 ` [RFC PATCH 3/7] sched/fair: Remove magic margin in fits_capacity() Qais Yousef
2023-09-06 14:38   ` Dietmar Eggemann
2023-09-06 21:45     ` Qais Yousef
2023-08-27 23:32 ` [RFC PATCH 4/7] sched: cpufreq: Remove magic 1.25 headroom from apply_dvfs_headroom() Qais Yousef
2023-09-07 11:34   ` Peter Zijlstra
2023-09-10 19:23     ` Qais Yousef
2023-08-27 23:32 ` [RFC PATCH 5/7] sched/schedutil: Add a new tunable to dictate response time Qais Yousef
2023-09-06 21:13   ` Dietmar Eggemann
2023-09-06 21:52     ` Qais Yousef
2023-09-07 11:44   ` Peter Zijlstra
2023-09-10 19:25     ` Qais Yousef
2023-08-27 23:32 ` [RFC PATCH 6/7] sched/pelt: Introduce PELT multiplier Qais Yousef
2023-08-27 23:32 ` [RFC PATCH 7/7] cpufreq: Change default transition delay to 2ms Qais Yousef
2023-09-06  9:18 ` [RFC PATCH 0/7] sched: cpufreq: Remove magic margins Lukasz Luba
2023-09-06 21:18   ` Qais Yousef
2023-09-07  7:48     ` Lukasz Luba
2023-09-07 11:53       ` Peter Zijlstra
2023-09-07 13:06         ` Lukasz Luba
2023-09-07 13:29           ` Peter Zijlstra
2023-09-07 13:33             ` Lukasz Luba
2023-09-07 13:38               ` Peter Zijlstra
2023-09-07 13:45                 ` Lukasz Luba
2023-09-08 12:51                   ` Daniel Bristot de Oliveira
2023-09-12 11:57                     ` Lukasz Luba
2023-09-10 18:20         ` Qais Yousef
2023-09-10 18:14       ` Qais Yousef
2023-09-07 13:26     ` Peter Zijlstra
2023-09-07 13:57       ` Lukasz Luba
2023-09-07 14:29         ` Peter Zijlstra
2023-09-07 14:42           ` Lukasz Luba
2023-09-07 20:16             ` Peter Zijlstra
2023-09-12 11:51               ` Lukasz Luba
2023-09-12 14:01                 ` Vincent Guittot
2023-09-13  9:53                   ` Lukasz Luba
2023-09-12 14:28                 ` Peter Zijlstra
2023-09-10 19:06             ` Qais Yousef
2023-09-10 18:46       ` Qais Yousef
2023-09-07 13:08 ` Peter Zijlstra
2023-09-08  0:17   ` Qais Yousef
2023-09-08  7:40     ` Dietmar Eggemann
2023-09-08 14:07       ` Qais Yousef
2023-09-12 17:18         ` Dietmar Eggemann
2023-09-16 19:38           ` Qais Yousef
2023-09-08 10:25     ` Peter Zijlstra
2023-09-08 13:33       ` Qais Yousef
2023-09-08 13:58         ` Peter Zijlstra
2023-09-08 13:59         ` Peter Zijlstra
2023-09-08 14:11           ` Qais Yousef
2023-09-10 21:17         ` Qais Yousef [this message]

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