linux-kernel - Re: [RFT][PATCH v1 0/5] cpuidle: menu: Avoid discarding useful information when processing recent idle intervals

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Message-ID: <4917ca35e5e0c7035f09c02d5080a69ed3e88c44.camel@linux.intel.com>
Date: Fri, 07 Feb 2025 16:48:37 +0200
From: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>, Linux PM
 <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>, Daniel Lezcano
	 <daniel.lezcano@...aro.org>, Christian Loehle <christian.loehle@....com>, 
 Aboorva Devarajan <aboorvad@...ux.ibm.com>
Subject: Re: [RFT][PATCH v1 0/5] cpuidle: menu: Avoid discarding useful
 information when processing recent idle intervals

Hi,

thanks for the patches!

On Thu, 2025-02-06 at 15:21 +0100, Rafael J. Wysocki wrote:
> Hi Everyone,
> 
> This work had been triggered by a report that commit 0611a640e60a ("eventpoll:
> prefer kfree_rcu() in __ep_remove()") had caused the critical-jOPS metric of
> the SPECjbb 2015 benchmark [1] to drop by around 50% even though it generally
> reduced kernel overhead.  Indeed, it was found during further investigation
> that the total interrupt rate while running the SPECjbb workload had fallen as
> a result of that commit by 55% and the local timer interrupt rate had fallen
> by
> almost 80%.

I ran SPECjbb2015 with and it doubles critical-jOPS and basically makes it
"normal" again. Thanks!

Reported-by: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>