From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e2.ny.us.ibm.com (e2.ny.us.ibm.com [32.97.182.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e2.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id D22E9B70E8 for ; Sat, 2 Oct 2010 04:29:51 +1000 (EST) Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233]) by e2.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o91IEdkr022432 for ; Fri, 1 Oct 2010 14:14:39 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o91ITl6c393988 for ; Fri, 1 Oct 2010 14:29:47 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o91ITicF023116 for ; Fri, 1 Oct 2010 14:29:46 -0400 Message-ID: <4CA62896.2060307@austin.ibm.com> Date: Fri, 01 Oct 2010 13:29:42 -0500 From: Nathan Fontenot MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 2/9] v3 Add mutex for adding/removing memory blocks References: <4CA62700.7010809@austin.ibm.com> In-Reply-To: <4CA62700.7010809@austin.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Cc: Greg KH , steiner@sgi.com, Robin Holt , KAMEZAWA Hiroyuki , Dave Hansen List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 | 7 +++++++ 1 file changed, 7 insertions(+) Index: linux-next/drivers/base/memory.c =================================================================== --- linux-next.orig/drivers/base/memory.c 2010-09-30 14:09:36.000000000 -0500 +++ linux-next/drivers/base/memory.c 2010-09-30 14:12:41.000000000 -0500 @@ -27,6 +27,8 @@ #include #include +static DEFINE_MUTEX(mem_sysfs_mutex); + #define MEMORY_CLASS_NAME "memory" static struct sysdev_class memory_sysdev_class = { @@ -476,6 +478,8 @@ if (!mem) return -ENOMEM; + mutex_lock(&mem_sysfs_mutex); + mem->phys_index = __section_nr(section); mem->state = state; mutex_init(&mem->state_mutex); @@ -496,6 +500,7 @@ ret = register_mem_sect_under_node(mem, nid); } + mutex_unlock(&mem_sysfs_mutex); return ret; } @@ -504,6 +509,7 @@ { struct memory_block *mem; + mutex_lock(&mem_sysfs_mutex); mem = find_memory_block(section); unregister_mem_sect_under_nodes(mem); mem_remove_simple_file(mem, phys_index); @@ -512,6 +518,7 @@ mem_remove_simple_file(mem, removable); unregister_memory(mem, section); + mutex_unlock(&mem_sysfs_mutex); return 0; }