From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id E1BFC620113 for ; Tue, 3 Aug 2010 09:31:36 -0400 (EDT) Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by e5.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o73DLYQo023957 for ; Tue, 3 Aug 2010 09:21:34 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o73DdpWh2175022 for ; Tue, 3 Aug 2010 09:39:52 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o73DdpCE007160 for ; Tue, 3 Aug 2010 09:39:51 -0400 Message-ID: <4C581C26.5080007@austin.ibm.com> Date: Tue, 03 Aug 2010 08:39:50 -0500 From: Nathan Fontenot MIME-Version: 1.0 Subject: [PATCH 4/9] v4 Add mutex for add/remove of memory blocks References: <4C581A6D.9030908@austin.ibm.com> In-Reply-To: <4C581A6D.9030908@austin.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org Cc: Greg KH , KAMEZAWA Hiroyuki , Dave Hansen List-ID: Add a new mutex for use in adding and removing of memory blocks. This is needed to avoid any race conditions in which the same memory block could be added and removed at the same time. Signed-off-by: Nathan Fontenot --- drivers/base/memory.c | 9 +++++++++ 1 file changed, 9 insertions(+) Index: linux-2.6/drivers/base/memory.c =================================================================== --- linux-2.6.orig/drivers/base/memory.c 2010-08-02 13:35:00.000000000 -0500 +++ linux-2.6/drivers/base/memory.c 2010-08-02 13:45:34.000000000 -0500 @@ -27,6 +27,8 @@ #include #include +static struct mutex mem_sysfs_mutex; + #define MEMORY_CLASS_NAME "memory" static struct sysdev_class memory_sysdev_class = { @@ -485,6 +487,8 @@ static int add_memory_block(int nid, str if (!mem) return -ENOMEM; + mutex_lock(&mem_sysfs_mutex); + mem->start_phys_index = __section_nr(section); mem->state = state; atomic_inc(&mem->section_count); @@ -508,6 +512,7 @@ static int add_memory_block(int nid, str ret = register_mem_sect_under_node(mem, nid); } + mutex_unlock(&mem_sysfs_mutex); return ret; } @@ -516,6 +521,7 @@ int remove_memory_block(unsigned long no { struct memory_block *mem; + mutex_lock(&mem_sysfs_mutex); mem = find_memory_block(section); if (atomic_dec_and_test(&mem->section_count)) { @@ -528,6 +534,7 @@ int remove_memory_block(unsigned long no unregister_memory(mem, section); } + mutex_unlock(&mem_sysfs_mutex); return 0; } @@ -562,6 +569,8 @@ int __init memory_dev_init(void) if (ret) goto out; + mutex_init(&mem_sysfs_mutex); + /* * Create entries for memory sections that were found * during boot and have been initialized -- 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