From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754039Ab2BBWrO (ORCPT ); Thu, 2 Feb 2012 17:47:14 -0500 Received: from na3sys009aog103.obsmtp.com ([74.125.149.71]:48887 "EHLO na3sys009aog103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753776Ab2BBWrN (ORCPT ); Thu, 2 Feb 2012 17:47:13 -0500 From: Kevin Hilman To: paulmck@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org Subject: Re: [PATCH RFC 0/41] RCU commits for 3.4 Organization: Texas Instruments, Inc. References: <20120201194131.GA10028@linux.vnet.ibm.com> Date: Thu, 02 Feb 2012 14:47:14 -0800 In-Reply-To: <20120201194131.GA10028@linux.vnet.ibm.com> (Paul E. McKenney's message of "Wed, 1 Feb 2012 11:41:31 -0800") Message-ID: <871uqcc0p9.fsf@ti.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, "Paul E. McKenney" writes: > This patchset makes RCU more aggressive about entering dyntick-idle mode > in order to improve energy efficiency, I gave this series a spin on an ARM/SMP platform (OMAP4) and the boot hung (tail end of boot log below.) I then realized that had isolcpus=1 on the cmdline from a previous experiment. Removing isolcpus from the cmdline got me back to a working boot. IIRC, some want to remove isolcpus, so I'm not sure if it's expected to work with your series, but thought you'd want to know. Kevin [ 1.105834] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled [ 1.353942] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 104) is a OMAP UART0 [ 1.462707] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 105) is a OMAP UART1 [ 1.548614] omap_uart.2: ttyO2 at MMIO 0x48020000 (irq = 106) is a OMAP UART2 [ 1.556304] console [ttyO2] enabled, bootconsole disabled [ 1.556304] console [ttyO2] enabled, bootconsole disabled [ 61.587493] INFO: rcu_sched detected stalls on CPUs/tasks: { 1} (detected by 0, t=7682 jiffies) [ 61.596649] INFO: Stall ended before state dump start