From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: Re: [RFC PATCH v4 12/13] memory-hotplug : add node_device_release Date: Fri, 27 Jul 2012 14:17:19 +0800 Message-ID: <5012326F.80702@cn.fujitsu.com> References: <50068974.1070409@jp.fujitsu.com> <50068D41.9090109@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50068D41.9090109@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: Yasuaki Ishimatsu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com List-Id: linux-acpi@vger.kernel.org At 07/18/2012 06:17 PM, Yasuaki Ishimatsu Wrote: > When calling unregister_node(), the function shows following message at > device_release(). > > Device 'node2' does not have a release() function, it is broken and must be > fixed. > > So the patch implements node_device_release() > > CC: David Rientjes > CC: Jiang Liu > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Wen Congyang > Signed-off-by: Yasuaki Ishimatsu > > --- > drivers/base/node.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > Index: linux-3.5-rc6/drivers/base/node.c > =================================================================== > --- linux-3.5-rc6.orig/drivers/base/node.c 2012-07-18 18:24:29.191121066 +0900 > +++ linux-3.5-rc6/drivers/base/node.c 2012-07-18 18:25:47.111146983 +0900 > @@ -252,6 +252,12 @@ static inline void hugetlb_register_node > static inline void hugetlb_unregister_node(struct node *node) {} > #endif > > +static void node_device_release(struct device *dev) > +{ > + struct node *node_dev = to_node(dev); > + > + memset(node_dev, 0, sizeof(struct node)); This line is wrong. node_dev->work_struct may be queued in workqueue. So, it is very dangerous to clear node_dev->work_struct here. In my test, it will cause kernel panicked. Thanks Wen Congyang > +} > > /* > * register_node - Setup a sysfs device for a node. > @@ -265,6 +271,7 @@ int register_node(struct node *node, int > > node->dev.id = num; > node->dev.bus = &node_subsys; > + node->dev.release = node_device_release; > error = device_register(&node->dev); > > if (!error){ > > -- > 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/ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from song.cn.fujitsu.com (unknown [222.73.24.84]) by ozlabs.org (Postfix) with ESMTP id AC07E2C0078 for ; Fri, 27 Jul 2012 16:12:26 +1000 (EST) Message-ID: <5012326F.80702@cn.fujitsu.com> Date: Fri, 27 Jul 2012 14:17:19 +0800 From: Wen Congyang MIME-Version: 1.0 To: Yasuaki Ishimatsu Subject: Re: [RFC PATCH v4 12/13] memory-hotplug : add node_device_release References: <50068974.1070409@jp.fujitsu.com> <50068D41.9090109@jp.fujitsu.com> In-Reply-To: <50068D41.9090109@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Cc: len.brown@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paulus@samba.org, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, rientjes@google.com, cl@linux.com, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, liuj97@gmail.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , At 07/18/2012 06:17 PM, Yasuaki Ishimatsu Wrote: > When calling unregister_node(), the function shows following message at > device_release(). > > Device 'node2' does not have a release() function, it is broken and must be > fixed. > > So the patch implements node_device_release() > > CC: David Rientjes > CC: Jiang Liu > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Wen Congyang > Signed-off-by: Yasuaki Ishimatsu > > --- > drivers/base/node.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > Index: linux-3.5-rc6/drivers/base/node.c > =================================================================== > --- linux-3.5-rc6.orig/drivers/base/node.c 2012-07-18 18:24:29.191121066 +0900 > +++ linux-3.5-rc6/drivers/base/node.c 2012-07-18 18:25:47.111146983 +0900 > @@ -252,6 +252,12 @@ static inline void hugetlb_register_node > static inline void hugetlb_unregister_node(struct node *node) {} > #endif > > +static void node_device_release(struct device *dev) > +{ > + struct node *node_dev = to_node(dev); > + > + memset(node_dev, 0, sizeof(struct node)); This line is wrong. node_dev->work_struct may be queued in workqueue. So, it is very dangerous to clear node_dev->work_struct here. In my test, it will cause kernel panicked. Thanks Wen Congyang > +} > > /* > * register_node - Setup a sysfs device for a node. > @@ -265,6 +271,7 @@ int register_node(struct node *node, int > > node->dev.id = num; > node->dev.bus = &node_subsys; > + node->dev.release = node_device_release; > error = device_register(&node->dev); > > if (!error){ > > -- > 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/ > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752659Ab2G0GM0 (ORCPT ); Fri, 27 Jul 2012 02:12:26 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:8369 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751597Ab2G0GMY (ORCPT ); Fri, 27 Jul 2012 02:12:24 -0400 X-IronPort-AV: E=Sophos;i="4.77,665,1336320000"; d="scan'208";a="5493556" Message-ID: <5012326F.80702@cn.fujitsu.com> Date: Fri, 27 Jul 2012 14:17:19 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com Subject: Re: [RFC PATCH v4 12/13] memory-hotplug : add node_device_release References: <50068974.1070409@jp.fujitsu.com> <50068D41.9090109@jp.fujitsu.com> In-Reply-To: <50068D41.9090109@jp.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/27 14:12:48, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/27 14:12:52, Serialize complete at 2012/07/27 14:12:52 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-2022-JP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At 07/18/2012 06:17 PM, Yasuaki Ishimatsu Wrote: > When calling unregister_node(), the function shows following message at > device_release(). > > Device 'node2' does not have a release() function, it is broken and must be > fixed. > > So the patch implements node_device_release() > > CC: David Rientjes > CC: Jiang Liu > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Wen Congyang > Signed-off-by: Yasuaki Ishimatsu > > --- > drivers/base/node.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > Index: linux-3.5-rc6/drivers/base/node.c > =================================================================== > --- linux-3.5-rc6.orig/drivers/base/node.c 2012-07-18 18:24:29.191121066 +0900 > +++ linux-3.5-rc6/drivers/base/node.c 2012-07-18 18:25:47.111146983 +0900 > @@ -252,6 +252,12 @@ static inline void hugetlb_register_node > static inline void hugetlb_unregister_node(struct node *node) {} > #endif > > +static void node_device_release(struct device *dev) > +{ > + struct node *node_dev = to_node(dev); > + > + memset(node_dev, 0, sizeof(struct node)); This line is wrong. node_dev->work_struct may be queued in workqueue. So, it is very dangerous to clear node_dev->work_struct here. In my test, it will cause kernel panicked. Thanks Wen Congyang > +} > > /* > * register_node - Setup a sysfs device for a node. > @@ -265,6 +271,7 @@ int register_node(struct node *node, int > > node->dev.id = num; > node->dev.bus = &node_subsys; > + node->dev.release = node_device_release; > error = device_register(&node->dev); > > if (!error){ > > -- > 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/ >