Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756966Ab2BHLLv (ORCPT ); Wed, 8 Feb 2012 06:11:51 -0500 Received: from mga03.intel.com ([143.182.124.21]:6993 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756794Ab2BHLLu (ORCPT ); Wed, 8 Feb 2012 06:11:50 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="104458051" Date: Wed, 8 Feb 2012 19:01:44 +0800 From: Wu Fengguang To: Andrew Morton Cc: linux-fsdevel@vger.kernel.org, LKML , Jens Axboe , Li Shaohua Subject: [PATCH] block: remove plugging at buffered write time Message-ID: <20120208110143.GA5550@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2617 Lines: 83 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); 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/