linux-kernel - Re: [PATCH 11/19] sched/fair: Identify busiest sched

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: <20251015152402.GE3168635@noisy.programming.kicks-ass.net>
Date: Wed, 15 Oct 2025 17:24:02 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Tim Chen <tim.c.chen@...ux.intel.com>
Cc: Ingo Molnar <mingo@...hat.com>,
	K Prateek Nayak <kprateek.nayak@....com>,
	"Gautham R . Shenoy" <gautham.shenoy@....com>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Juri Lelli <juri.lelli@...hat.com>,
	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>,
	Madadi Vineeth Reddy <vineethr@...ux.ibm.com>,
	Hillf Danton <hdanton@...a.com>,
	Shrikanth Hegde <sshegde@...ux.ibm.com>,
	Jianyong Wu <jianyong.wu@...look.com>,
	Yangyu Chen <cyy@...self.name>,
	Tingyin Duan <tingyin.duan@...il.com>,
	Vern Hao <vernhao@...cent.com>, Len Brown <len.brown@...el.com>,
	Aubrey Li <aubrey.li@...el.com>, Zhao Liu <zhao1.liu@...el.com>,
	Chen Yu <yu.chen.surf@...il.com>, Chen Yu <yu.c.chen@...el.com>,
	Libo Chen <libo.chen@...cle.com>,
	Adam Li <adamli@...amperecomputing.com>,
	Tim Chen <tim.c.chen@...el.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 11/19] sched/fair: Identify busiest sched_group for
 LLC-aware load balancing

On Sat, Oct 11, 2025 at 11:24:48AM -0700, Tim Chen wrote:

> @@ -11035,6 +11059,17 @@ static bool update_sd_pick_busiest(struct lb_env *env,
>  	     sds->local_stat.group_type != group_has_spare))
>  		return false;
>  
> +	/* deal with prefer LLC load balance, if failed, fall into normal load balance */
> +	if (update_llc_busiest(env, busiest, sgs))
> +		return true;
> +
> +	/*
> +	 * If the busiest group has tasks with LLC preference,
> +	 * skip normal load balance.
> +	 */
> +	if (busiest->group_llc_balance)
> +		return false;
> +
>  	if (sgs->group_type > busiest->group_type)
>  		return true;

This feels weird.. should we really override things like group_imbalance
or group_misfit_task ?