From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>,
mingo@redhat.com, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, vschneid@redhat.com,
linux-kernel@vger.kernel.org, Chris Mason <clm@meta.com>,
Joseph Salisbury <joseph.salisbury@oracle.com>,
Adam Li <adamli@os.amperecomputing.com>,
Hazem Mohamed Abuelfotoh <abuehaze@amazon.com>,
Josh Don <joshdon@google.com>
Subject: Re: [PATCH 2/4] sched/fair: Small cleanup to sched_balance_newidle()
Date: Fri, 14 Nov 2025 12:05:10 +0100 [thread overview]
Message-ID: <20251114110510.GT278048@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CAKfTPtAk=GAKBDdJve-V-FuMgGPD5hNA0rTL5v4SV0G5ha3a+g@mail.gmail.com>
On Fri, Nov 14, 2025 at 11:22:48AM +0100, Vincent Guittot wrote:
> sched_balance_update_blocked_averages() can be costly so we want to
> include it in the sd->max_idle_balance_cost so we skip newidle lb and
> update blocked load if avg_idle is shorter than doin the update and
> the newidle lb of the 1st level
Ah, fair enough.
> when sd is null we should still skip
> sched_balance_update_blocked_averages() is its cost is higher than
> avg_idle but it seems that we don't.
When !sd there is no balancing to be had.
Anyway, I'll keep the patch as is -- introducing an early exit for !sd
and I'll post a few more cleanups after this.
next prev parent reply other threads:[~2025-11-14 11:05 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-07 16:06 [PATCH 0/4] sched: The newidle balance regression Peter Zijlstra
2025-11-07 16:06 ` [PATCH 1/4] sched/fair: Revert max_newidle_lb_cost bump Peter Zijlstra
2025-11-14 12:19 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2025-11-17 16:23 ` tip-bot2 for Peter Zijlstra
2025-11-07 16:06 ` [PATCH 2/4] sched/fair: Small cleanup to sched_balance_newidle() Peter Zijlstra
2025-11-10 13:55 ` Dietmar Eggemann
2025-11-10 14:04 ` Peter Zijlstra
2025-11-12 14:37 ` Shrikanth Hegde
2025-11-12 14:42 ` Peter Zijlstra
2025-11-12 15:08 ` Peter Zijlstra
2025-11-12 15:28 ` Shrikanth Hegde
2025-11-14 9:49 ` Peter Zijlstra
2025-11-14 10:22 ` Vincent Guittot
2025-11-14 11:05 ` Peter Zijlstra [this message]
2025-11-14 13:11 ` Vincent Guittot
2025-11-14 12:19 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2025-11-17 16:23 ` tip-bot2 for Peter Zijlstra
2025-11-07 16:06 ` [PATCH 3/4] sched/fair: Small cleanup to update_newidle_cost() Peter Zijlstra
2025-11-14 12:19 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2025-11-17 16:23 ` tip-bot2 for Peter Zijlstra
2025-11-07 16:06 ` [PATCH 4/4] sched/fair: Proportional newidle balance Peter Zijlstra
2025-11-10 13:55 ` Dietmar Eggemann
2025-11-11 9:07 ` Adam Li
2025-11-11 9:20 ` Peter Zijlstra
2025-11-12 12:04 ` Adam Li
2025-11-12 13:41 ` Peter Zijlstra
2025-11-12 15:42 ` Shrikanth Hegde
2025-11-14 9:35 ` Peter Zijlstra
2025-11-14 12:18 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2025-11-17 16:23 ` tip-bot2 for Peter Zijlstra
2026-01-18 20:46 ` [PATCH 4/4] " Mario Roy
2026-01-23 10:50 ` Peter Zijlstra
2026-01-23 11:03 ` Peter Zijlstra
2026-01-23 12:24 ` K Prateek Nayak
2026-01-28 4:08 ` K Prateek Nayak
2026-01-27 4:15 ` Mario Roy
2026-01-27 10:40 ` Peter Zijlstra
2026-01-27 15:17 ` Peter Zijlstra
2026-01-30 1:44 ` Mario Roy
2026-01-30 4:14 ` Mario Roy
2026-02-24 9:13 ` [tip: sched/core] sched/fair: More complex proportional " tip-bot2 for Peter Zijlstra
2026-01-25 12:22 ` [PATCH 4/4] sched/fair: Proportional " Mohamed Abuelfotoh, Hazem
2026-01-27 8:44 ` Peter Zijlstra
2026-01-28 15:48 ` Mohamed Abuelfotoh, Hazem
2026-01-29 9:19 ` Peter Zijlstra
2026-01-29 9:24 ` Peter Zijlstra
2026-01-30 16:12 ` Mohamed Abuelfotoh, Hazem
2026-01-30 13:16 ` Mohamed Abuelfotoh, Hazem
2026-02-02 10:51 ` Peter Zijlstra
2026-02-02 11:07 ` Mohamed Abuelfotoh, Hazem
2026-02-04 12:45 ` Mohamed Abuelfotoh, Hazem
2026-02-04 13:27 ` Peter Zijlstra
2026-02-04 13:59 ` Mohamed Abuelfotoh, Hazem
2026-02-04 14:05 ` Peter Zijlstra
2026-02-04 22:48 ` Mohamed Abuelfotoh, Hazem
2026-01-27 8:50 ` Peter Zijlstra
2026-01-27 9:13 ` Peter Zijlstra
2026-01-28 16:24 ` Mohamed Abuelfotoh, Hazem
2026-01-28 16:03 ` Mohamed Abuelfotoh, Hazem
2026-04-29 8:51 ` Qing Wang
2026-05-06 2:44 ` [PATCH] sched/fair: Replace random newidle_balance with Bresenham accumulator Qing Wang
2025-11-10 19:47 ` [PATCH 0/4] sched: The newidle balance regression Chris Mason
2025-11-11 19:08 ` Josh Don
2025-11-12 21:59 ` Chris Mason
2025-11-14 9:37 ` Peter Zijlstra
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