Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757847AbYAUBme (ORCPT ); Sun, 20 Jan 2008 20:42:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756607AbYAUBm1 (ORCPT ); Sun, 20 Jan 2008 20:42:27 -0500 Received: from fg-out-1718.google.com ([72.14.220.156]:57205 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756462AbYAUBm0 (ORCPT ); Sun, 20 Jan 2008 20:42:26 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=Uppq0+pGkvPo7bgvKuyS+2c0PN66b5yk5J7n4sr6Mouwkxl6PC4ef7aoETjb5gSSiX9EL6h5K+UDKyUvXNf27cLQscXBr45V6wa8BMYuCOgXEU3L7c9J3K+/GHBxzw/gU/Y0ln4q+YlLSrXlCJtT7ddNzYHBPv+QMmvIUwNuGJU= Date: Mon, 21 Jan 2008 09:43:35 +0800 From: Dave Young To: Jarek Poplawski Cc: Kay Sievers , Alan Stern , Greg KH , stefanr@s5r6.in-berlin.de, David Brownell , Kernel development list Subject: Re: [PATCH 7/7] driver-core : convert semaphore to mutex in struct class Message-ID: <20080121014335.GA3219@darkstar.te-china.tietoenator.com> References: <3ae72650801171755k85c4245i3b4c46a84ae8f52d@mail.gmail.com> <1200626323.5640.21.camel@lov.site> <20080118073836.GA1703@ff.dom.local> <20080118082327.GC1703@ff.dom.local> <4791C555.9050205@gmail.com> <20080121013021.GB2832@darkstar.te-china.tietoenator.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080121013021.GB2832@darkstar.te-china.tietoenator.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9131 Lines: 319 On Mon, Jan 21, 2008 at 09:30:21AM +0800, Dave Young wrote: > On Sat, Jan 19, 2008 at 10:39:33AM +0100, Jarek Poplawski wrote: > > Dave Young wrote, On 01/18/2008 10:07 AM: > > > > > On Jan 18, 2008 4:23 PM, Jarek Poplawski wrote: > > > > >> On Fri, Jan 18, 2008 at 03:48:02PM +0800, Dave Young wrote: > > > > ... > > > > >>> 1) Using CLASS_NORMAL/CLASS_PARENT/CLASS_CHILD will be enough. > > >>> or > > >>> 2) Simply add SINGLE_LEVEL_NESTING in class_device_add and other > > >>> class_device functions because it is the only possible nest-lock place > > >>> as I know. > > > > > Althoug the class_device will be away soon, the patch is updated as following because the problem is clear and only several lines are changed. At least, it could be used for test. > > > Convert the class semaphore to mutex. > class_interface_register/unregister use class_device_* functions, so SINGLE_DEPTH_NESTING added for lockdep please in these functions. > > Signed-off-by: Dave Young > Sorry for the dirty patch, please don't test the previous one. I should have drink a cup of coffe before posting. post the right one again. --- Convert the class semaphore to mutex. class_interface_register/unregister use class_device_* functions, so SINGLE_DEPTH_NESTING added for lockdep please in these functions. Signed-off-by: Dave Young --- drivers/base/class.c | 38 +++++++++++++++++++------------------- drivers/base/core.c | 18 ++++++++---------- include/linux/device.h | 3 ++- 3 files changed, 29 insertions(+), 30 deletions(-) Index: linux-2.6.23/drivers/base/class.c =================================================================== --- linux-2.6.23.orig/drivers/base/class.c 2008-01-21 09:36:43.000000000 +0800 +++ linux-2.6.23/drivers/base/class.c 2008-01-21 09:38:14.000000000 +0800 @@ -144,7 +144,7 @@ INIT_LIST_HEAD(&cls->devices); INIT_LIST_HEAD(&cls->interfaces); kset_init(&cls->class_dirs); - init_MUTEX(&cls->sem); + mutex_init(&cls->mutex); error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name); if (error) return error; @@ -617,13 +617,13 @@ kobject_uevent(&class_dev->kobj, KOBJ_ADD); /* notify any interfaces this device is now here */ - down(&parent_class->sem); + mutex_lock_nested(&parent_class->mutex, SINGLE_DEPTH_NESTING); list_add_tail(&class_dev->node, &parent_class->children); list_for_each_entry(class_intf, &parent_class->interfaces, node) { if (class_intf->add) class_intf->add(class_dev, class_intf); } - up(&parent_class->sem); + mutex_unlock(&parent_class->mutex); goto out1; @@ -725,12 +725,12 @@ struct class_interface *class_intf; if (parent_class) { - down(&parent_class->sem); + mutex_lock_nested(&parent_class->mutex, SINGLE_DEPTH_NESTING); list_del_init(&class_dev->node); list_for_each_entry(class_intf, &parent_class->interfaces, node) if (class_intf->remove) class_intf->remove(class_dev, class_intf); - up(&parent_class->sem); + mutex_unlock(&parent_class->mutex); } if (class_dev->dev) { @@ -772,14 +772,14 @@ struct class_device *class_dev = NULL; struct class_device *class_dev_tmp; - down(&cls->sem); + mutex_lock_nested(&cls->mutex, SINGLE_DEPTH_NESTING); list_for_each_entry(class_dev_tmp, &cls->children, node) { if (class_dev_tmp->devt == devt) { class_dev = class_dev_tmp; break; } } - up(&cls->sem); + mutex_unlock(&cls->mutex); if (class_dev) class_device_unregister(class_dev); @@ -818,7 +818,7 @@ if (!class) return -EINVAL; - down(&class->sem); + mutex_lock(&class->mutex); list_for_each_entry(dev, &class->devices, node) { dev = get_device(dev); if (dev) { @@ -829,7 +829,7 @@ if (error) break; } - up(&class->sem); + mutex_unlock(&class->mutex); return error; } @@ -860,7 +860,7 @@ if (!class) return NULL; - down(&class->sem); + mutex_lock(&class->mutex); list_for_each_entry(dev, &class->devices, node) { dev = get_device(dev); if (dev) { @@ -872,7 +872,7 @@ } else break; } - up(&class->sem); + mutex_unlock(&class->mutex); return found ? dev : NULL; } @@ -898,7 +898,7 @@ if (!class) return -EINVAL; - down(&class->sem); + mutex_lock(&class->mutex); list_for_each_entry(dev, &class->children, node) { dev = class_device_get(dev); if (dev) { @@ -909,7 +909,7 @@ if (error) break; } - up(&class->sem); + mutex_unlock(&class->mutex); return error; } @@ -940,7 +940,7 @@ if (!class) return NULL; - down(&class->sem); + mutex_lock(&class->mutex); list_for_each_entry(dev, &class->children, node) { dev = class_device_get(dev); if (dev) { @@ -952,7 +952,7 @@ } else break; } - up(&class->sem); + mutex_unlock(&class->mutex); return found ? dev : NULL; } @@ -971,7 +971,7 @@ if (!parent) return -EINVAL; - down(&parent->sem); + mutex_lock(&parent->mutex); list_add_tail(&class_intf->node, &parent->interfaces); if (class_intf->add) { list_for_each_entry(class_dev, &parent->children, node) @@ -981,7 +981,7 @@ list_for_each_entry(dev, &parent->devices, node) class_intf->add_dev(dev, class_intf); } - up(&parent->sem); + mutex_unlock(&parent->mutex); return 0; } @@ -995,7 +995,7 @@ if (!parent) return; - down(&parent->sem); + mutex_lock(&parent->mutex); list_del_init(&class_intf->node); if (class_intf->remove) { list_for_each_entry(class_dev, &parent->children, node) @@ -1005,7 +1005,7 @@ list_for_each_entry(dev, &parent->devices, node) class_intf->remove_dev(dev, class_intf); } - up(&parent->sem); + mutex_unlock(&parent->mutex); class_put(parent); } Index: linux-2.6.23/drivers/base/core.c =================================================================== --- linux-2.6.23.orig/drivers/base/core.c 2008-01-21 09:35:37.000000000 +0800 +++ linux-2.6.23/drivers/base/core.c 2008-01-21 09:36:47.000000000 +0800 @@ -19,8 +19,6 @@ #include #include -#include - #include "base.h" #include "power/power.h" @@ -783,7 +781,7 @@ klist_add_tail(&dev->knode_parent, &parent->klist_children); if (dev->class) { - down(&dev->class->sem); + mutex_lock(&dev->class->mutex); /* tie the class to the device */ list_add_tail(&dev->node, &dev->class->devices); @@ -791,7 +789,7 @@ list_for_each_entry(class_intf, &dev->class->interfaces, node) if (class_intf->add_dev) class_intf->add_dev(dev, class_intf); - up(&dev->class->sem); + mutex_unlock(&dev->class->mutex); } Done: put_device(dev); @@ -928,14 +926,14 @@ sysfs_remove_link(&dev->kobj, "device"); } - down(&dev->class->sem); + mutex_lock(&dev->class->mutex); /* notify any interfaces that the device is now gone */ list_for_each_entry(class_intf, &dev->class->interfaces, node) if (class_intf->remove_dev) class_intf->remove_dev(dev, class_intf); /* remove the device from the class list */ list_del_init(&dev->node); - up(&dev->class->sem); + mutex_unlock(&dev->class->mutex); /* If we live in a parent class-directory, unreference it */ if (dev->kobj.parent->kset == &dev->class->class_dirs) { @@ -946,7 +944,7 @@ * if we are the last child of our class, delete * our class-directory at this parent */ - down(&dev->class->sem); + mutex_lock(&dev->class->mutex); list_for_each_entry(d, &dev->class->devices, node) { if (d == dev) continue; @@ -959,7 +957,7 @@ kobject_del(dev->kobj.parent); kobject_put(dev->kobj.parent); - up(&dev->class->sem); + mutex_unlock(&dev->class->mutex); } } device_remove_file(dev, &uevent_attr); @@ -1168,14 +1166,14 @@ struct device *dev = NULL; struct device *dev_tmp; - down(&class->sem); + mutex_lock(&class->mutex); list_for_each_entry(dev_tmp, &class->devices, node) { if (dev_tmp->devt == devt) { dev = dev_tmp; break; } } - up(&class->sem); + mutex_unlock(&class->mutex); if (dev) device_unregister(dev); Index: linux-2.6.23/include/linux/device.h =================================================================== --- linux-2.6.23.orig/include/linux/device.h 2008-01-21 09:36:43.000000000 +0800 +++ linux-2.6.23/include/linux/device.h 2008-01-21 09:36:47.000000000 +0800 @@ -20,6 +20,7 @@ #include #include #include + #include #include #include #include @@ -180,7 +181,7 @@ struct list_head devices; struct list_head interfaces; struct kset class_dirs; - struct semaphore sem; /* locks children, devices, interfaces */ + struct mutex mutex; /* locks children, devices, interfaces */ struct class_attribute * class_attrs; struct class_device_attribute * class_dev_attrs; struct device_attribute * dev_attrs; -- 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/