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 DCA046B02C4 for ; Mon, 9 Aug 2010 14:38:52 -0400 (EDT) Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e6.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o79IcETQ027781 for ; Mon, 9 Aug 2010 14:38:14 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o79IcmH6137328 for ; Mon, 9 Aug 2010 14:38:48 -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 o79IcmaJ020411 for ; Mon, 9 Aug 2010 14:38:48 -0400 Message-ID: <4C604B36.4070603@austin.ibm.com> Date: Mon, 09 Aug 2010 13:38:46 -0500 From: Nathan Fontenot MIME-Version: 1.0 Subject: [PATCH 4/8] v5 Add mutex for add/remove of memory blocks References: <4C60407C.2080608@austin.ibm.com> In-Reply-To: <4C60407C.2080608@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: KAMEZAWA Hiroyuki , Dave Hansen , Greg KH 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 | 7 +++++++ 1 file changed, 7 insertions(+) Index: linux-2.6/drivers/base/memory.c =================================================================== --- linux-2.6.orig/drivers/base/memory.c 2010-08-09 07:49:04.000000000 -0500 +++ linux-2.6/drivers/base/memory.c 2010-08-09 07:50:20.000000000 -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 = { @@ -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; } -- 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