Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761428AbZDGWTy (ORCPT ); Tue, 7 Apr 2009 18:19:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761101AbZDGWTo (ORCPT ); Tue, 7 Apr 2009 18:19:44 -0400 Received: from THUNK.ORG ([69.25.196.29]:59750 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760859AbZDGWTn (ORCPT ); Tue, 7 Apr 2009 18:19:43 -0400 Date: Tue, 7 Apr 2009 18:19:33 -0400 From: Theodore Tso To: Jens Axboe , Andrew Morton , Linux Kernel Developers List , Ext4 Developers List , jack@suse.cz Subject: [PATCH] block_write_full_page: switch synchronous writes to use WRITE_SYNC_PLUG Message-ID: <20090407221933.GB7031@mit.edu> Mail-Followup-To: Theodore Tso , Jens Axboe , Andrew Morton , Linux Kernel Developers List , Ext4 Developers List , jack@suse.cz References: <1238185471-31152-1-git-send-email-tytso@mit.edu> <1238185471-31152-2-git-send-email-tytso@mit.edu> <20090406232141.ebdb426a.akpm@linux-foundation.org> <20090406235052.1ea47513.akpm@linux-foundation.org> <20090407070835.GM5178@kernel.dk> <20090407002313.fcdd1da0.akpm@linux-foundation.org> <20090407075732.GO5178@kernel.dk> <20090407190913.GA31723@mit.edu> <20090407193239.GE5178@kernel.dk> <20090407214421.GA7031@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090407214421.GA7031@mit.edu> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1439 Lines: 40 Now that we have a distinction between WRITE_SYNC and WRITE_SYNC_PLUG, use WRITE_SYNC_PLUG in __block_write_full_page() to avoid unplugging the block device I/O queue between each page that gets flushed out. The upstream callers of block_write_full_page() which wait for the writes to finish call wait_on_buffer(), wait_on_writeback_range() (which ultimately calls sync_page(), which calls blk_run_backing_dev(), which will unplug the device queue), and so on. Signed-off-by: "Theodore Ts'o" --- We should get this applied to avoid any performance regressions resulting from commit a64c8610. fs/buffer.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 977e12a..95b5390 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1646,7 +1646,8 @@ static int __block_write_full_page(struct inode *inode, struct page *page, struct buffer_head *bh, *head; const unsigned blocksize = 1 << inode->i_blkbits; int nr_underway = 0; - int write_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); + int write_op = (wbc->sync_mode == WB_SYNC_ALL ? + WRITE_SYNC_PLUG : WRITE); BUG_ON(!PageLocked(page)); -- 1.5.6.3 -- 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/