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From: Peter Zijlstra <peterz@infradead.org>
To: Lukasz Luba <lukasz.luba@arm.com>
Cc: Qais Yousef <qyousef@layalina.io>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Viresh Kumar <viresh.kumar@linaro.org>
Subject: Re: [RFC PATCH 0/7] sched: cpufreq: Remove magic margins
Date: Thu, 7 Sep 2023 15:29:06 +0200	[thread overview]
Message-ID: <20230907132906.GG10955@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <89067f71-9b83-e647-053e-07f7d55b6529@arm.com>

On Thu, Sep 07, 2023 at 02:06:15PM +0100, Lukasz Luba wrote:

> > Many extentions to the periodic task model are possible, including
> > things like average runtime with bursts etc.. all have their trade-offs.
> 
> Was that maybe proposed somewhere on LKML (the other models)?

RT literatur mostly methinks. Replacing WCET with a statistical model of
sorts is not uncommon, the argument goes that not everybody will have
their worst case at the same time and lows and highs can commonly cancel
out and this way we can cram a little more on the system.

Typically this is proposed in the context of soft-realtime systems.

  reply	other threads:[~2023-09-07 15:35 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 [this message]
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

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