linux-kernel - Re: stable: commit "cpuidle: menu: Avoid discarding useful information" causes regressions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2025101451-unlinked-strongly-2fb3@gregkh>
Date: Tue, 14 Oct 2025 09:47:24 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: Sergey Senozhatsky <senozhatsky@...omium.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>,
	Christian Loehle <christian.loehle@....com>,
	Sasha Levin <sashal@...nel.org>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
	Tomasz Figa <tfiga@...omium.org>, stable@...r.kernel.org
Subject: Re: stable: commit "cpuidle: menu: Avoid discarding useful
 information" causes regressions

On Tue, Oct 14, 2025 at 04:43:43PM +0900, Sergey Senozhatsky wrote:
> Hello,
> 
> We are observing performance regressions (cpu usage, power
> consumption, dropped frames in video playback test, etc.)
> after updating to recent stable kernels.  We tracked it down
> to commit 3cd2aa93674e in linux-6.1.y and commit 3cd2aa93674
> in linux-6.6.y ("cpuidle: menu: Avoid discarding useful information",
> upstream commit 85975daeaa4).
> 
> Upstream fixup fa3fa55de0d ("cpuidle: governors: menu: Avoid using
> invalid recent intervals data") doesn't address the problems we are
> observing.  Revert seems to be bringing performance metrics back to
> pre-regression levels.
> 

For some reason that commit was not added to the 6.1 releases, sorry
about that.  Can you submit a working/tested backport so we can queue it
up after the next round of releases in a few days?

thanks,

greg k-h