From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759968Ab3E3TlN (ORCPT ); Thu, 30 May 2013 15:41:13 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:55085 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759827Ab3E3TlB (ORCPT ); Thu, 30 May 2013 15:41:01 -0400 From: "Rafael J. Wysocki" To: Yinghai Lu Cc: Greg Kroah-Hartman , ACPI Devel Maling List , Linux Kernel Mailing List , Toshi Kani , Daniel Lezcano Subject: [PATCH] ACPI / processor: Initialize per_cpu(processors, pr->id) properly (Re: System slow down from udev) Date: Thu, 30 May 2013 21:49:57 +0200 Message-ID: <3972909.bTSgjJ1tfq@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0-rc3+; KDE/4.9.5; x86_64; ; ) In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, May 30, 2013 11:12:30 AM Yinghai Lu wrote: > On Thu, May 30, 2013 at 10:42 AM, Yinghai Lu wrote: > > On Thu, May 30, 2013 at 9:36 AM, Rafael J. Wysocki wrote: > > > do you need to remove > > per_cpu(processors, pr->id) = NULL; > > from processor_driver.c::acpi_processor_stop ? > > updated patch. Thanks! Appended is essentially the same one with a changelog and tags. Thanks, Rafael --- From: Rafael J. Wysocki Subject: ACPI / processor: Initialize per_cpu(processors, pr->id) properly Commit ac212b6 (ACPI / processor: Use common hotplug infrastructure) forgot about initializing the per-CPU 'processors' variables which lead to ACPI cpuidle failure to use C-states and caused boot slowdown on multi-CPU machines. Fix the problem by adding per_cpu(processors, pr->id) initialization to acpi_processor_add() and add make acpi_processor_remove() clean it up as appropriate. Also modify acpi_processor_stop() so that it doesn't clear per_cpu(processors, pr->id) on processor driver removal which would then cause problems to happen when the driver is loaded again. This version of the patch contains fixes from Yinghai Lu. Reported-and-tested-by: Yinghai Lu Reported-and-tested-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_processor.c | 6 ++++++ drivers/acpi/processor_driver.c | 5 ----- 2 files changed, 6 insertions(+), 5 deletions(-) Index: linux-pm/drivers/acpi/processor_driver.c =================================================================== --- linux-pm.orig/drivers/acpi/processor_driver.c +++ linux-pm/drivers/acpi/processor_driver.c @@ -78,9 +78,6 @@ static struct device_driver acpi_process .remove = acpi_processor_stop, }; -DEFINE_PER_CPU(struct acpi_processor *, processors); -EXPORT_PER_CPU_SYMBOL(processors); - static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) { struct acpi_device *device = data; @@ -268,8 +265,6 @@ static int acpi_processor_stop(struct de thermal_cooling_device_unregister(pr->cdev); pr->cdev = NULL; } - - per_cpu(processors, pr->id) = NULL; return 0; } Index: linux-pm/drivers/acpi/acpi_processor.c =================================================================== --- linux-pm.orig/drivers/acpi/acpi_processor.c +++ linux-pm/drivers/acpi/acpi_processor.c @@ -29,6 +29,9 @@ ACPI_MODULE_NAME("processor"); +DEFINE_PER_CPU(struct acpi_processor *, processors); +EXPORT_PER_CPU_SYMBOL(processors); + /* -------------------------------------------------------------------------- Errata Handling -------------------------------------------------------------------------- */ @@ -387,6 +390,7 @@ static int __cpuinit acpi_processor_add( * checks. */ per_cpu(processor_device_array, pr->id) = device; + per_cpu(processors, pr->id) = pr; dev = get_cpu_device(pr->id); result = acpi_bind_one(dev, pr->handle); @@ -406,6 +410,7 @@ static int __cpuinit acpi_processor_add( err: free_cpumask_var(pr->throttling.shared_cpu_map); device->driver_data = NULL; + per_cpu(processors, pr->id) = NULL; err_free_pr: kfree(pr); return result; @@ -440,6 +445,7 @@ static void acpi_processor_remove(struct /* Clean up. */ per_cpu(processor_device_array, pr->id) = NULL; + per_cpu(processors, pr->id) = NULL; try_offline_node(cpu_to_node(pr->id)); /* Remove the CPU. */