From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753199AbXCMJ5i (ORCPT ); Tue, 13 Mar 2007 05:57:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753206AbXCMJ5d (ORCPT ); Tue, 13 Mar 2007 05:57:33 -0400 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:4649 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753199AbXCMJ5F (ORCPT ); Tue, 13 Mar 2007 05:57:05 -0400 Date: Tue, 13 Mar 2007 09:56:52 +0000 From: Russell King To: Heiko Carstens , Andreas Schwab , Giuliano Pochini , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, Suresh Siddha Subject: Re: /sys/devices/system/cpu/cpuX/online are missing Message-ID: <20070313095652.GB20518@flint.arm.linux.org.uk> Mail-Followup-To: Heiko Carstens , Andreas Schwab , Giuliano Pochini , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, Suresh Siddha References: <20070311222652.5ea40da1.pochini@shiny.it> <20070312085826.GA9985@osiris.boeblingen.de.ibm.com> <20070313090350.GA9890@osiris.boeblingen.de.ibm.com> <20070313091159.GB9890@osiris.boeblingen.de.ibm.com> <20070313094038.GA20518@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070313094038.GA20518@flint.arm.linux.org.uk> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 13, 2007 at 09:40:39AM +0000, Russell King wrote: > On Tue, Mar 13, 2007 at 10:11:59AM +0100, Heiko Carstens wrote: > > On Tue, Mar 13, 2007 at 10:03:50AM +0100, Heiko Carstens wrote: > > > I was referring to arch/ppc not arch/powerpc. But it seems that arch/ppc > > > doesn't support cpu hotplug anyway. So I guess it's indeed just a missing > > > config option. > > > > > > Grepping a bit further shows that arm suffered by the change that inverted > > > the logic if the 'online' attribute for cpus should appear. Since arm > > > supports cpu hotplug but the patch left arm out, it doesn't work there > > > anymore (cc'ing arm people: changeset 72486f1f8f0a2bc828b9d30cf4690cf2dd6807fc > > > is most probably disabling cpu hotplug support on arm like it did on s390). > > > > Should have cc'ed Suresh Siddha who caused the breakage ;) > > Welcome to why cleanups are bad news. ;( Yes, ARM also needs to be fixed > and I'd ask that in future people doing cleanups in core code take a little > more time to review the code before submitting patches *AND* give heads-up > to *EVERYONE* who might be affected by the change. Right, here's the ARM fix which is now in the ARM tree: # Base git commit: 8b9909ded6922c33c221b105b26917780cfa497d # (Merge branch 'merge' of master.kernel.org:/pub/scm/linux/kernel/git/paulus/powerpc) # # Author: Russell King (Tue Mar 13 09:54:21 GMT 2007) # Committer: Russell King (Tue Mar 13 09:54:21 GMT 2007) # # [ARM] Fix breakage caused by 72486f1f8f0a2bc828b9d30cf4690cf2dd6807fc # # 72486f1f8f0a2bc828b9d30cf4690cf2dd6807fc inverted the sense for # enabling hotplug CPU controls without reference to any other # architecture other than i386, ia64 and PowerPC. This left # everyone else without hotplug CPU control. # # Fix ARM for this brain damage. # # Signed-off-by: Russell King # # arch/arm/kernel/setup.c | 7 +++++-- # 1 files changed, 5 insertions(+), 2 deletions(-) # diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 03e37af..0453dcc 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -839,8 +839,11 @@ static int __init topology_init(void) { int cpu; - for_each_possible_cpu(cpu) - register_cpu(&per_cpu(cpu_data, cpu).cpu, cpu); + for_each_possible_cpu(cpu) { + struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu); + cpuinfo->cpu.hotpluggable = 1; + register_cpu(&cpuinfo->cpu, cpu); + } return 0; } -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: