Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965307Ab2EOCRo (ORCPT ); Mon, 14 May 2012 22:17:44 -0400 Received: from mail1.windriver.com ([147.11.146.13]:52758 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964822Ab2EOCQA (ORCPT ); Mon, 14 May 2012 22:16:00 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 003/179] CPU hotplug, re-create sysfs directory and symlinks Date: Mon, 14 May 2012 22:11:39 -0400 Message-ID: <1337048075-6132-4-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2761 Lines: 77 From: Jacob Shin ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034 upstream. When we discover CPUs that are affected by each other's frequency/voltage transitions, the first CPU gets a sysfs directory created, and rest of the siblings get symlinks. Currently, when we hotplug off only the first CPU, all of the symlinks and the sysfs directory gets removed. Even though rest of the siblings are still online and functional, they are orphaned, and no longer governed by cpufreq. This patch, given the above scenario, creates a sysfs directory for the first sibling and symlinks for the rest of the siblings. Please note the recursive call, it was rather too ugly to roll it out. And the removal of redundant NULL setting (it is already taken care of near the top of the function). Signed-off-by: Jacob Shin Acked-by: Mark Langsdorf Reviewed-by: Thomas Renninger Signed-off-by: Dave Jones Signed-off-by: Paul Gortmaker --- drivers/cpufreq/cpufreq.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 634757f..cb18598 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1216,12 +1216,28 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) cpufreq_driver->exit(data); unlock_policy_rwsem_write(cpu); + cpufreq_debug_enable_ratelimit(); + +#ifdef CONFIG_HOTPLUG_CPU + /* when the CPU which is the parent of the kobj is hotplugged + * offline, check for siblings, and create cpufreq sysfs interface + * and symlinks + */ + if (unlikely(cpumask_weight(data->cpus) > 1)) { + /* first sibling now owns the new sysfs dir */ + cpumask_clear_cpu(cpu, data->cpus); + cpufreq_add_dev(get_cpu_sysdev(cpumask_first(data->cpus))); + + /* finally remove our own symlink */ + lock_policy_rwsem_write(cpu); + __cpufreq_remove_dev(sys_dev); + } +#endif + free_cpumask_var(data->related_cpus); free_cpumask_var(data->cpus); kfree(data); - per_cpu(cpufreq_cpu_data, cpu) = NULL; - cpufreq_debug_enable_ratelimit(); return 0; } -- 1.7.9.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/