linux-kernel - Re: [PATCH V3 1/2] sched: Reduce the default slice to avoid tasks getting an extra tick

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Message-ID: <20250210091352.GC10324@noisy.programming.kicks-ass.net>
Date: Mon, 10 Feb 2025 10:13:52 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: Qais Yousef <qyousef@...alina.io>
Cc: zihan zhou <15645113830zzh@...il.com>, bsegall@...gle.com,
	dietmar.eggemann@....com, juri.lelli@...hat.com,
	linux-kernel@...r.kernel.org, mgorman@...e.de, mingo@...hat.com,
	rostedt@...dmis.org, vincent.guittot@...aro.org,
	vschneid@...hat.com
Subject: Re: [PATCH V3 1/2] sched: Reduce the default slice to avoid tasks
 getting an extra tick

On Mon, Feb 10, 2025 at 01:29:31AM +0000, Qais Yousef wrote:

> I brought the topic up of these magic values with Peter and Vincent in LPC as
> I think this logic is confusing. I have nothing against your patch, but if the
> maintainers agree I am in favour of removing it completely in favour of setting
> it to a single value that is the same across all systems.

You're talking about the scaling, right?

Yeah, it is of limited use. The cap at 8, combined with the fact that
its really hard to find a machine with less than 8 CPUs on, makes the
whole thing mostly useless.

Back when we did this, we still had dual-core laptops. Now phones have
8 or more CPUs on.

So I don't think I mind ripping it out.