From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 0087F37B3FD; Mon, 19 Jan 2026 14:26:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768832784; cv=none; b=swvSPb6XAOCAXcRGZmUAhF3o0B+EOGhQOygkzE1diDuzEQhwthyV2VFVm6Ui8AJ6eNyBu9W2cUd5PGYxCWl6ll3awrRiOiWof5/Kh4oYQ2y/PXz7NFYpK9lkmJpJHzEfx9ApgVgeOucsuzK73XvEOSEtFW6TmmXkzAO5XLszbTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768832784; c=relaxed/simple; bh=m6aD/X2y0FNcAmZ9GWybNcS/CHc+XooX2ctcxGXuAmw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s2M+PEAyyQ/k+8xivTbiBtcOTWdu8gtv3ZJC+W+pigQQX6vMZJELJipu5AQ2U6xzYk1pWoeUZETM8M7pslUeV6MSaDMufZh9RkmV8JNmuIK/FrsJxDZfmeCnfORjp/pdfw8bAKCzVHB1/6IICWQW4YMJOZUcDqZ0C1bJDYHY0Ek= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=phVpzmPF; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="phVpzmPF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=J7YR6Ss4GR1p+SXEIbKvrV+9SeOL7XVCLDPQxRbp/9Q=; b=phVpzmPFu1Lg5Wwsu+BOkmfOW+ 7MEiiANgQ2k/WAjssImTBsBtsTReEql3LfWeR3eFCTJMcXjNSQuIO7LbmizlIxbjd7SrLLSKCcBSp aDO/nN6wrUdvONoFpb1boJnDyyb9lER3VTnG9922Knms3+B9j6HFUVGinLdmiEyvhWAyM1emPfId0 3ejQrUhO0sHyp8rUFpwu26JS3ZZq0CPSKVHkIzEgF64hdM1+c+1BQTsyQUJrF/KtLBbP6GFbLLb2j Jm6wiXTO8fSdUEnK92SIQIyQQDwiIUBCAg2WEYqWULtN4+kC03qtQtM6yeOYdsHHp/DqXmbnbADUG Oa7LNwWA==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhqCm-0000000CGLf-3TCN; Mon, 19 Jan 2026 14:26:09 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id DA8703006CD; Mon, 19 Jan 2026 15:26:07 +0100 (CET) Date: Mon, 19 Jan 2026 15:26:07 +0100 From: Peter Zijlstra To: Frederic Weisbecker Cc: LKML , "Christophe Leroy (CS GROUP)" , "Rafael J. Wysocki" , Alexander Gordeev , Anna-Maria Behnsen , Ben Segall , Boqun Feng , Christian Borntraeger , Dietmar Eggemann , Heiko Carstens , Ingo Molnar , Jan Kiszka , Joel Fernandes , Juri Lelli , Kieran Bingham , Madhavan Srinivasan , Mel Gorman , Michael Ellerman , Neeraj Upadhyay , Nicholas Piggin , "Paul E . McKenney" , Steven Rostedt , Sven Schnelle , Thomas Gleixner , Uladzislau Rezki , Valentin Schneider , Vasily Gorbik , Vincent Guittot , Viresh Kumar , Xin Zhao , linux-pm@vger.kernel.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 06/15] tick/sched: Unify idle cputime accounting Message-ID: <20260119142607.GG830229@noisy.programming.kicks-ass.net> References: <20260116145208.87445-1-frederic@kernel.org> <20260116145208.87445-7-frederic@kernel.org> 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: <20260116145208.87445-7-frederic@kernel.org> On Fri, Jan 16, 2026 at 03:51:59PM +0100, Frederic Weisbecker wrote: > +#ifdef CONFIG_NO_HZ_COMMON > +void kcpustat_dyntick_start(void) > +{ > + if (!vtime_generic_enabled_this_cpu()) { > + vtime_dyntick_start(); > + __this_cpu_write(kernel_cpustat.idle_dyntick, 1); > + } > +} Why don't we need to make sure steal time is up-to-date at this point? > +void kcpustat_dyntick_stop(void) > +{ > + if (!vtime_generic_enabled_this_cpu()) { > + __this_cpu_write(kernel_cpustat.idle_dyntick, 0); > + vtime_dyntick_stop(); > + steal_account_process_time(ULONG_MAX); > + } > +} > +#endif /* CONFIG_NO_HZ_COMMON */