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From: Lukasz Luba <lukasz.luba@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
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 14:33:49 +0100	[thread overview]
Message-ID: <5616e50d-b827-4547-5b16-9131ace98419@arm.com> (raw)
In-Reply-To: <20230907132906.GG10955@noisy.programming.kicks-ass.net>



On 9/7/23 14:29, Peter Zijlstra wrote:
> 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.

Thanks Peter, I will dive into some books...

  reply	other threads:[~2023-09-07 18:22 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 [this message]
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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