Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756545Ab0HCNjy (ORCPT ); Tue, 3 Aug 2010 09:39:54 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:55149 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756275Ab0HCNjx (ORCPT ); Tue, 3 Aug 2010 09:39:53 -0400 Message-ID: <4C581C26.5080007@austin.ibm.com> Date: Tue, 03 Aug 2010 08:39:50 -0500 From: Nathan Fontenot User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org CC: Greg KH , KAMEZAWA Hiroyuki , Dave Hansen 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2011 Lines: 70 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 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/