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 6D0C3205E26; Wed, 21 Jan 2026 16:55:31 +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=1769014531; cv=none; b=FmPtyaDNNCqlvyBAOT3MTl754fXZLYG2hNg7OwUnEApJ8sajKGn9CLpgZY5s1oeEHlNT7Lz3OzkD6jsUCryBNq1oZ1fIsmmYzyfxx7JR3XXR3DnN7vvVNtB5QaIpmDfbXu3lmvTEaDt+dUfgv3AUr3lVg9Hm+jNll1RH+wlhFnk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769014531; c=relaxed/simple; bh=mxuQx8myh37sFEu9+vJLmpyCKKaNhjPDjdia8zaYzsE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WLUduW0qf+1XzsQLomfF3gGkeRJOO71FsB9a6SvbJODGTiMRpW1MF0VtAyAR3trvnsrU6oJSFQ+Dvk4Rd5b9VretB5a6JS4FY+O8rQ/XB6LkqVN4tCYoYCtbJ9eKCsWCRLCytbTu25PrWShpysst/tm09xAQYylyzkoaI4D7MJ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i4zQlP9q; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i4zQlP9q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F892C4CEF1; Wed, 21 Jan 2026 16:55:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769014531; bh=mxuQx8myh37sFEu9+vJLmpyCKKaNhjPDjdia8zaYzsE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i4zQlP9qJjB6AQvf49Y9Ufsh9lLsJ6bgZDrju7360I1I550ZnhpWAwEhlEoR9En0J y6/+oLJdJnMdYltuM3MRou3lpBFM3dQjjN6PzEResWJIqV+XkmAk4eyCJq2+1ZLjyD aQLh3joSmHc4hig6Ewwj3u3Tl6EQRXKppt8VR+cgGDTQdrlYJVRKNFZqvklqakPBWY OWXFLzFKVuyDHwqGzad53oDQuURAzIfzlqt4EtTh8VHFtXd/0GY3pZh+ePdP1ub/q3 F4FRPA0IyGS9x8qxwRk/fYy0I+TKHGub9a3Sp7PBRLyZBWkY/dcH8M84Au0PkruVH+ OEqS1sr2cxlOg== Date: Wed, 21 Jan 2026 17:55:27 +0100 From: Frederic Weisbecker To: Shrikanth Hegde Cc: LKML , "Rafael J . Wysocki" , Boqun Feng , Thomas Gleixner , Steven Rostedt , "Christophe Leroy (CS GROUP)" , Kieran Bingham , Ben Segall , Michael Ellerman , Ingo Molnar , Vincent Guittot , Juri Lelli , Neeraj Upadhyay , Xin Zhao , Madhavan Srinivasan , Mel Gorman , Valentin Schneider , Christian Borntraeger , Jan Kiszka , linuxppc-dev@lists.ozlabs.org, "Paul E . McKenney" , Viresh Kumar , Anna-Maria Behnsen , Uladzislau Rezki , Dietmar Eggemann , Heiko Carstens , linux-pm@vger.kernel.org, Alexander Gordeev , Sven Schnelle , Vasily Gorbik , Joel Fernandes , Nicholas Piggin , linux-s390@vger.kernel.org, Peter Zijlstra Subject: Re: [PATCH 00/15] tick/sched: Refactor idle cputime accounting Message-ID: References: <20260116145208.87445-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Le Tue, Jan 20, 2026 at 06:12:08PM +0530, Shrikanth Hegde a écrit : > > Hi Frederic. > > On 1/16/26 8:27 PM, Frederic Weisbecker wrote: > > I forgot to mention I haven't yet tested CONFIG_VIRT_CPU_ACCOUNTING_NATIVE > > (s390 and powerpc). > > > > Thanks. > > > tl;dr > > I ran this on powerNV(Non virtualized) with 144 CPUs with below config. (default ones) > Patch *breaks* the cpu idle stats most of the time. idle values are wrong. Right I somehow lost the TS_FLAG_INIDLE setting in tick_nohz_idle_enter(), which ruins the whole thing. You probably think I should have detected that with light testing and you're right. Not checking dmesg was a bit sloppy from my end... I'm fixing that and will send a v2 soonish. Thanks a lot for testing! -- Frederic Weisbecker SUSE Labs