linux-kernel - Re: [PATCH 1/1] sched/deadline: Fix fair

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aFF6eYzMahzQ9sxE@jlelli-thinkpadt14gen4.remote.csb>
Date: Tue, 17 Jun 2025 16:23:53 +0200
From: Juri Lelli <juri.lelli@...hat.com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Kuyo Chang <kuyo.chang@...iatek.com>, Ingo Molnar <mingo@...hat.com>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Dietmar Eggemann <dietmar.eggemann@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
	Valentin Schneider <vschneid@...hat.com>,
	Matthias Brugger <matthias.bgg@...il.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	jstultz <jstultz@...gle.com>, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH 1/1] sched/deadline: Fix fair_server runtime calculation
 formula

On 17/06/25 16:14, Peter Zijlstra wrote:
> On Tue, Jun 17, 2025 at 02:33:15PM +0200, Juri Lelli wrote:

...

> > To me it looks like we want this (no scaling) for fair_server (and
> > possibly scx_server?) as for them we are only looking into a 'fixed
> > time' type of isolation. Full fledged servers (hierarchical scheduling)
> > maybe have it configurable, or enabled by default as a start (as we have
> > it today).
> 
> Right. Then we should write the above like:
> 
> 	scaled_delta_exec = delta_exec;
> 	if (!dl_se->dl_server)
> 		scaled_delta_exec = dl_scaled_delta_exec(rq, dl_se, delta_exec);
> 
> and let any later server users add bits on if they want more options.

Works for me. Looks cleaner also.

Kuyo, can you please update your patch then?

Thanks,
Juri