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From: Peter Zijlstra <peterz@infradead.org>
To: 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>
Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	vschneid@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH 0/4] sched: The newidle balance regression
Date: Fri, 07 Nov 2025 17:06:45 +0100	[thread overview]
Message-ID: <20251107160645.929564468@infradead.org> (raw)

Hi!

So most of you ran into Chris' commit 155213a2aed4 ("sched/fair: Bump
sd->max_newidle_lb_cost when newidle balance fails") [*]

And I posted a patch with a few alternative options. And while I've heard back
from a number of you, indicating that NI_TARGET (the effective revert) works
for you. Not many tested TARGET+RANDOM (thanks Adam!).

In my limited schbench testing that combination isn't horrible, and per Adam
that combination also doesn't suck for him. Chris, could you please see what
this does for your machines with your actual workload?

Anyway, here are a few patches that basically do the revert and introduce the
proportional newidle balance -- the NI_TARGET+NI_RANDOM equivalent.

Also at:

  git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/newidle

Please all, give it a whirl. Hopefully I didn't wreck it, its Friday after all :-)

[*] https://lkml.kernel.org/r/006c9df2-b691-47f1-82e6-e233c3f91faf@oracle.com



             reply	other threads:[~2025-11-07 16:18 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-07 16:06 Peter Zijlstra [this message]
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
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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