Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932253Ab2BIBRG (ORCPT ); Wed, 8 Feb 2012 20:17:06 -0500 Received: from mga09.intel.com ([134.134.136.24]:24996 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757655Ab2BIBRE (ORCPT ); Wed, 8 Feb 2012 20:17:04 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="105494842" Subject: Re: [PATCH] block: remove plugging at buffered write time From: Shaohua Li To: Wu Fengguang Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, LKML , Jens Axboe In-Reply-To: <20120208110143.GA5550@localhost> References: <20120208110143.GA5550@localhost> Content-Type: text/plain; charset="UTF-8" Date: Thu, 09 Feb 2012 09:14:49 +0800 Message-ID: <1328750089.5949.1.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2907 Lines: 91 On Wed, 2012-02-08 at 19:01 +0800, Wu Fengguang wrote: > Buffered write(2) is not directly tied to IO, so it's not suitable to > handle plug in generic_file_aio_write(). > > Also remove the redundant plug calls around ->direct_IO(), since we now > do unplugging in the lower layer do_blockdev_direct_IO(). > > CC: Jens Axboe > CC: Li Shaohua > Signed-off-by: Wu Fengguang > --- > fs/direct-io.c | 4 ++++ > mm/filemap.c | 7 ------- > 2 files changed, 4 insertions(+), 7 deletions(-) > > --- linux-next.orig/mm/filemap.c 2012-02-08 18:51:50.000000000 +0800 > +++ linux-next/mm/filemap.c 2012-02-08 18:52:19.000000000 +0800 > @@ -1421,12 +1421,8 @@ generic_file_aio_read(struct kiocb *iocb > retval = filemap_write_and_wait_range(mapping, pos, > pos + iov_length(iov, nr_segs) - 1); > if (!retval) { > - struct blk_plug plug; > - > - blk_start_plug(&plug); > retval = mapping->a_ops->direct_IO(READ, iocb, > iov, pos, nr_segs); > - blk_finish_plug(&plug); > } > if (retval > 0) { > *ppos = pos + retval; > @@ -2610,13 +2606,11 @@ ssize_t generic_file_aio_write(struct ki > { > struct file *file = iocb->ki_filp; > struct inode *inode = file->f_mapping->host; > - struct blk_plug plug; > ssize_t ret; > > BUG_ON(iocb->ki_pos != pos); > > mutex_lock(&inode->i_mutex); > - blk_start_plug(&plug); > ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); > mutex_unlock(&inode->i_mutex); > > @@ -2627,7 +2621,6 @@ ssize_t generic_file_aio_write(struct ki > if (err < 0 && ret > 0) > ret = err; > } > - blk_finish_plug(&plug); > return ret; > } > EXPORT_SYMBOL(generic_file_aio_write); > --- linux-next.orig/fs/direct-io.c 2012-02-08 18:51:37.000000000 +0800 > +++ linux-next/fs/direct-io.c 2012-02-08 18:52:19.000000000 +0800 > @@ -1106,6 +1106,7 @@ do_blockdev_direct_IO(int rw, struct kio > unsigned long user_addr; > size_t bytes; > struct buffer_head map_bh = { 0, }; > + struct blk_plug plug; > > if (rw & WRITE) > rw = WRITE_ODIRECT; > @@ -1221,6 +1222,8 @@ do_blockdev_direct_IO(int rw, struct kio > PAGE_SIZE - user_addr / PAGE_SIZE); > } > > + blk_start_plug(&plug); > + > for (seg = 0; seg < nr_segs; seg++) { > user_addr = (unsigned long)iov[seg].iov_base; > sdio.size += bytes = iov[seg].iov_len; > @@ -1314,6 +1317,7 @@ do_blockdev_direct_IO(int rw, struct kio > } else > BUG_ON(retval != -EIOCBQUEUED); > > + blk_finish_plug(&plug); This one can be moved up a little bit (before dio_cleanup) Thanks, Shaohua > out: > return retval; > } -- 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/