From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965560AbXCMJFn (ORCPT ); Tue, 13 Mar 2007 05:05:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965478AbXCMJFn (ORCPT ); Tue, 13 Mar 2007 05:05:43 -0400 Received: from mtagate3.uk.ibm.com ([195.212.29.136]:63770 "EHLO mtagate3.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965560AbXCMJFm (ORCPT ); Tue, 13 Mar 2007 05:05:42 -0400 Date: Tue, 13 Mar 2007 10:03:50 +0100 From: Heiko Carstens To: Andreas Schwab Cc: Giuliano Pochini , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, spyro@f2s.com, rmk@arm.linux.org.uk Subject: Re: /sys/devices/system/cpu/cpuX/online are missing Message-ID: <20070313090350.GA9890@osiris.boeblingen.de.ibm.com> References: <20070311222652.5ea40da1.pochini@shiny.it> <20070312085826.GA9985@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: mutt-ng/devel-r804 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 13, 2007 at 01:39:25AM +0100, Andreas Schwab wrote: > Giuliano Pochini writes: > > > I had a look at arch/powerpc/kernel/smp.c but I'm not familiar at all with > > those parts of the kernel. > > See arch/powerpc/kernel/sysfs.c:topology_init. I don't think there is > anything to do here. You probably don't have CONFIG_HOTPLUG_CPU enabled. 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).