From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 889281D5AC6; Tue, 14 Oct 2025 08:02:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760428964; cv=none; b=glxOQMfccU/BNvziK3azQaajJsP6V53Vu3eHy1t3aFOcZ4LgyOB2Ek3DARhusRxr5nQkfO1tJsnPk2SnejwiFPYLo7os+dSdfbHHeTAYFZVNfOqfLV/+M9T71rASJgg0gkcJWuVgoIX2+qbggc6+qG3LpVjBCWGYmEimYIw6u8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760428964; c=relaxed/simple; bh=dGBxSxLw0RN6Zij1QQZIpEgNum+sah9NeStZCIuXt5k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mbFlmnSdtd0EgYiuExD1QtwYA+rgx+MuermYT77u8Pmcjaobz1dhYd+uK6Vp+y+JVE/n6elUQckR/Ll4A0eZkJm8RHBcEuc/uv634azBOpobyA/1QSloOUWOLFF0FN62lEAk4EixLGQBbrkXU1aKDlvN30GaeBE7mrTsCwF/TfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=S5sYnA0x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="S5sYnA0x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9AD5C4CEE7; Tue, 14 Oct 2025 08:02:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760428964; bh=dGBxSxLw0RN6Zij1QQZIpEgNum+sah9NeStZCIuXt5k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S5sYnA0xKvEFRdaB05kNJp6g26WnjSak25gaLqR5seEdSU5H+eecEVlfCBI8A5XzG f2NyGsgJ0asYF0AQ1tcltxc2QgKHxZZ/T3G04XW50dtoHtPYZAFF1KId/SuRioqGO3 o0NTHfsb6WxYcNYIxEa9UXa/j7AFIq2pezB+b5z0= Date: Tue, 14 Oct 2025 10:02:41 +0200 From: Greg Kroah-Hartman To: Sergey Senozhatsky Cc: "Rafael J. Wysocki" , Artem Bityutskiy , Christian Loehle , Sasha Levin , Daniel Lezcano , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Tomasz Figa , stable@vger.kernel.org Subject: Re: stable: commit "cpuidle: menu: Avoid discarding useful information" causes regressions Message-ID: <2025101421-citrus-barley-9061@gregkh> References: <36iykr223vmcfsoysexug6s274nq2oimcu55ybn6ww4il3g3cv@cohflgdbpnq7> <2025101451-unlinked-strongly-2fb3@gregkh> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Oct 14, 2025 at 04:54:45PM +0900, Sergey Senozhatsky wrote: > On (25/10/14 09:47), Greg Kroah-Hartman wrote: > > 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? > > Sorry for the confusion, the commit in question presents both in > stable 6.1 and in 6.6 and appears to be causing regressions on our > tests. I copy-pasted wrong commit id for 6.1: it should be a9edb700846 > for 6.1 (and 3cd2aa93674 for 6.6). > The point is still the same, commit fa3fa55de0d6 ("cpuidle: governors: menu: Avoid using invalid recent intervals data"), is not backported to 6.1.y, it is however in the following released kernels: 5.10.241 5.15.190 6.6.103 6.12.43 6.15.11 6.16.2 6.17 so something got lost in our trees and it needs to be backported. I need to knock up a "what patches are missing" script again and sweep the trees to catch these types of things. It's been a year or so since I last did that. thanks, greg k-h