Date: Tue, 21 Aug 2012 16:37:38 +0900
From: Minchan Kim <minchan@kernel.org>
To: Wen Congyang <wency@cn.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, mgorman@suse.de,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, hughd@google.com,
        linux-mm@kvack.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] memory hotplug: reset pgdat->kswapd to NULL if creating
 kernel thread fails
Message-ID: <20120821073738.GA24667@bbox>
References: <50332B37.2000500@cn.fujitsu.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <50332B37.2000500@cn.fujitsu.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 904
Lines: 21

On Tue, Aug 21, 2012 at 02:31:19PM +0800, Wen Congyang wrote:
> 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 <wency@cn.fujitsu.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>

Nitpick: Why doesn't online_pages check kswapd_run's return value?
         I hope memory-hotplug can handle this error rightly without
         relying on this patch in the future.

-- 
Kind regards,
Minchan Kim
--
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/