From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q3ODO0jT070176 for ; Tue, 24 Apr 2012 08:24:00 -0500 Received: from mail-pb0-f53.google.com (mail-pb0-f53.google.com [209.85.160.53]) by cuda.sgi.com with ESMTP id CS97ehDl8sj54Rrj (version=TLSv1 cipher=RC4-SHA bits=128 verify=NO) for ; Tue, 24 Apr 2012 06:23:59 -0700 (PDT) Received: by pbcuo1 with SMTP id uo1so141312pbc.26 for ; Tue, 24 Apr 2012 06:23:58 -0700 (PDT) Date: Tue, 24 Apr 2012 21:23:46 +0800 From: Shaohua Li Subject: Re: [RFC]xfs: using GFP_NOFS for blkdev_issue_flush Message-ID: <20120424132346.GA24575@kernel.org> References: <4F8BC112.9090508@fusionio.com> <4F8BC30D.5040601@kernel.org> <20120418013746.GL6734@dastard> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120418013746.GL6734@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: hch@infradead.org, xfs@oss.sgi.com On Wed, Apr 18, 2012 at 11:37:46AM +1000, Dave Chinner wrote: > On Mon, Apr 16, 2012 at 02:58:21PM +0800, Shaohua Li wrote: > > On 4/16/12 2:49 PM, Shaohua Li wrote: > > > > > >flush request is issued in transaction commit code path usually, so > > >looks using > > >GFP_KERNEL to allocate memory for flush request bio falls into the classic > > >deadlock issue (memory reclaim recursion). Use GFP_NOFS to avoid recursion > > >from reclaim context. Per Dave Chinner, there is only blkdev_issue_flush > > >might > > >be buggy here. But using GFP_NOFS by default for all calls should not > > >matter. > > Can you update the commit message like I suggested previously? Copied exactly. Issuing a block device flush request in transaction context using GFP_KERNEL directly can cause deadlocks due to memory reclaim recursion. Use GFP_NOFS to avoid recursion from reclaim context. Signed-off-by: Shaohua Li Reviewed-by: Mark Tinguely --- fs/xfs/xfs_super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/fs/xfs/xfs_super.c =================================================================== --- linux.orig/fs/xfs/xfs_super.c 2012-04-13 10:08:26.095496072 +0800 +++ linux/fs/xfs/xfs_super.c 2012-04-13 10:08:42.555496865 +0800 @@ -622,7 +622,7 @@ void xfs_blkdev_issue_flush( xfs_buftarg_t *buftarg) { - blkdev_issue_flush(buftarg->bt_bdev, GFP_KERNEL, NULL); + blkdev_issue_flush(buftarg->bt_bdev, GFP_NOFS, NULL); } STATIC void _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs