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From: Matt Fleming <matt@readmodwrite.com>
To: yu.c.chen@intel.com
Cc: aaron.lu@intel.com, dietmar.eggemann@arm.com,
	gautham.shenoy@amd.com, juri.lelli@redhat.com,
	kprateek.nayak@amd.com, linux-kernel@vger.kernel.org,
	mgorman@techsingularity.net, mingo@redhat.com,
	peterz@infradead.org, tim.c.chen@intel.com,
	vincent.guittot@linaro.org, yu.chen.surf@gmail.com
Subject: Re: [RFC PATCH 0/7] Optimization to reduce the cost of newidle balance
Date: Tue, 16 Jul 2024 15:16:45 +0100	[thread overview]
Message-ID: <20240716141645.637620-1-mfleming@cloudflare.com> (raw)
In-Reply-To: <cover.1690273854.git.yu.c.chen@intel.com>

> Hi,
> 
> This is the second version of the newidle balance optimization[1].
> It aims to reduce the cost of newidle balance which is found to
> occupy noticeable CPU cycles on some high-core count systems.

Hi there, what's the status of this series?

I'm seeing this same symptom of burning cycles in update_sd_lb_stats() on an
AMD EPYC 7713 machine (128 CPUs, 8 NUMA nodes). The machine is about 50% idle
and upadte_sd_lb_stats() sits as the first entry in perf top with about 3.62%
of CPU cycles.

Thanks,
Matt

  parent reply	other threads:[~2024-07-16 14:16 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-27 14:33 Chen Yu
2023-07-27 14:34 ` [RFC PATCH 1/7] sched/topology: Assign sd_share for all non NUMA sched domains Chen Yu
2023-07-27 14:34 ` [RFC PATCH 2/7] sched/topology: Introduce nr_groups in sched_domain to indicate the number of groups Chen Yu
2023-07-27 14:34 ` [RFC PATCH 3/7] sched/fair: Save a snapshot of sched domain total_load and total_capacity Chen Yu
2023-07-27 14:35 ` [RFC PATCH 4/7] sched/fair: Calculate the scan depth for idle balance based on system utilization Chen Yu
2023-08-25  6:02   ` Shrikanth Hegde
2023-08-30 15:30     ` Chen Yu
2023-07-27 14:35 ` [RFC PATCH 5/7] sched/fair: Adjust the busiest group scanning depth in idle load balance Chen Yu
2023-08-25  6:00   ` Shrikanth Hegde
2023-08-30 15:35     ` Chen Yu
2023-07-27 14:35 ` [RFC PATCH 6/7] sched/fair: Pull from a relatively busy group during newidle balance Chen Yu
2023-07-27 14:35 ` [RFC PATCH 7/7] sched/stats: Track the scan number of groups during load balance Chen Yu
2023-08-25  7:48 ` [RFC PATCH 0/7] Optimization to reduce the cost of newidle balance Shrikanth Hegde
2023-08-30 15:26   ` Chen Yu
2023-09-10  7:51     ` Shrikanth Hegde
2024-07-16 14:16 ` Matt Fleming [this message]
2024-07-17  3:52   ` Chen Yu
2024-07-17 15:31     ` Matt Fleming
2024-07-17 12:17 ` Peter Zijlstra
2024-07-18  9:28   ` K Prateek Nayak
2024-07-18 17:01     ` Chen Yu
2024-07-18 16:57   ` Chen Yu

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