From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx104.postini.com [74.125.245.104]) by kanga.kvack.org (Postfix) with SMTP id EB5366B005D for ; Tue, 21 Aug 2012 02:43:56 -0400 (EDT) Message-ID: <50332B37.2000500@cn.fujitsu.com> Date: Tue, 21 Aug 2012 14:31:19 +0800 From: Wen Congyang MIME-Version: 1.0 Subject: [PATCH] memory hotplug: reset pgdat->kswapd to NULL if creating kernel thread fails Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , mgorman@suse.de, KAMEZAWA Hiroyuki , hughd@google.com, minchan@kernel.org, linux-mm@kvack.org, "linux-kernel@vger.kernel.org" If kthread_run() fails, pgdat->kswapd contains errno. When we stop this thread, we only check whether pgdat->kswapd is NULL and access it. If it contains errno, it will cause page fault. Reset pgdat->kswapd to NULL when creating kernel thread fails can avoid this problem. Signed-off-by: Wen Congyang --- mm/vmscan.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 347b3ff..1e8e2aa 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2953,6 +2953,7 @@ int kswapd_run(int nid) /* failure at boot is fatal */ BUG_ON(system_state == SYSTEM_BOOTING); printk("Failed to start kswapd on node %d\n",nid); + pgdat->kswapd = NULL; ret = -1; } return ret; -- 1.7.1 -- 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