From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755490AbbE2Gg0 (ORCPT ); Fri, 29 May 2015 02:36:26 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:33607 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755447AbbE2GgF (ORCPT ); Fri, 29 May 2015 02:36:05 -0400 From: Ming Lei To: linux-kernel@vger.kernel.org, Dave Kleikamp Cc: Jens Axboe , Zach Brown , Christoph Hellwig , Maxim Patlasov , Andrew Morton , Alexander Viro , Tejun Heo , Dave Chinner , Ming Lei Subject: [PATCH v4 2/5] block: loop: set QUEUE_FLAG_NOMERGES for request queue of loop Date: Fri, 29 May 2015 14:35:35 +0800 Message-Id: <1432881338-898-3-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1432881338-898-1-git-send-email-ming.lei@canonical.com> References: <1432881338-898-1-git-send-email-ming.lei@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It doesn't make sense to enable merge because the I/O submitted to backing file is handled page by page. Signed-off-by: Ming Lei --- drivers/block/loop.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 40580dc..10cc583 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1595,6 +1595,12 @@ static int loop_add(struct loop_device **l, int i) } lo->lo_queue->queuedata = lo; + /* + * It doesn't make sense to enable merge because the I/O + * submitted to backing file is handled page by page. + */ + queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, lo->lo_queue); + INIT_LIST_HEAD(&lo->write_cmd_head); INIT_WORK(&lo->write_work, loop_queue_write_work); -- 1.9.1