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From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Shijie Huang <shijie@amperemail.onmicrosoft.com>,
	Huang Shijie <shijie@os.amperecomputing.com>,
	mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org
Cc: patches@amperecomputing.com, cl@linux.com,
	Shubhang@os.amperecomputing.com, rostedt@goodmis.org,
	bsegall@google.com, mgorman@suse.de,
	linux-kernel@vger.kernel.org, vschneid@redhat.com,
	vineethr@linux.ibm.com, kprateek.nayak@amd.com
Subject: Re: [PATCH v6 2/2] sched: update the rq->avg_idle when a task is moved to an idle CPU
Date: Wed, 7 Jan 2026 16:48:38 +0100	[thread overview]
Message-ID: <6667e71b-a9ef-4c01-9453-171c07b2753f@arm.com> (raw)
In-Reply-To: <f898a0f0-8b77-4a71-be3b-c74267de0bde@arm.com>

On 17.12.25 17:15, Dietmar Eggemann wrote:
> On 15.12.25 10:35, Shijie Huang wrote:
>>
>> On 12/12/2025 22:22, Dietmar Eggemann wrote:

[...]

> I think Vincent is right by saying the update_rq_avg_idle() should be
> put into put_prev_task_idle() instead.
> 
> Still waiting for the DCPerf Mediawiki test results to see if this
> change fixes my 'rq->avg_idle being too big' issue.

Turns out the patch didn't fix this issue. Still seeing a huge number of
sched_balance_newidle() calls in which the system is (1) overloaded and
(2) this_rq->avg_idle >= sd->max_newidle_lb_cost so that there is no
early bailout and no task is pulled at the end. Must be something else ...

  reply	other threads:[~2026-01-07 15:48 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-09  9:45 [PATCH v6 0/2] " Huang Shijie
2025-12-09  9:45 ` [PATCH v6 1/2] sched/fair: set rq->idle_stamp at the end of the sched_balance_newidle Huang Shijie
2025-12-09  9:45 ` [PATCH v6 2/2] sched: update the rq->avg_idle when a task is moved to an idle CPU Huang Shijie
2025-12-11 16:15   ` Dietmar Eggemann
2025-12-12  3:16     ` Shijie Huang
2025-12-12 14:22       ` Dietmar Eggemann
2025-12-15  9:35         ` Shijie Huang
2025-12-17 16:15           ` Dietmar Eggemann
2026-01-07 15:48             ` Dietmar Eggemann [this message]
2026-01-09 13:33               ` Vincent Guittot
2025-12-13  1:36   ` Vincent Guittot
2025-12-16  6:22     ` Shijie Huang
2025-12-16  7:17       ` Vincent Guittot
2025-12-16  7:38         ` Shijie Huang
2025-12-16  8:47           ` Vincent Guittot
2025-12-16  9:49             ` Shijie Huang

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