From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:31645 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752931AbcCASgx (ORCPT ); Tue, 1 Mar 2016 13:36:53 -0500 Received: from pmta06.mandrill.prod.suw01.rsglab.com (127.0.0.1) by mail177-1.suw61.mandrillapp.com id hqngka22rtk0 for ; Tue, 1 Mar 2016 18:36:48 +0000 (envelope-from ) From: Subject: Patch "s390/dasd: fix performance drop" has been added to the 4.4-stable tree To: , , Cc: , Message-Id: <145685740610076@kroah.com> Date: Tue, 01 Mar 2016 18:36:48 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled s390/dasd: fix performance drop to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-dasd-fix-performance-drop.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 12d319b920fa673a4d5e7c1785c5dc82dcd15257 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Fri, 12 Feb 2016 14:50:52 +0100 Subject: s390/dasd: fix performance drop From: Stefan Haberland commit 12d319b920fa673a4d5e7c1785c5dc82dcd15257 upstream. Commit ca369d51b ("sd: Fix device-imposed transfer length limits") introduced a new queue limit max_dev_sectors which limits the maximum sectors for requests. The default value leads to small dasd requests and therefor to a performance drop. Set the max_dev_sectors value to the same value as the max_hw_sectors to use the maximum available request size for DASD devices. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -3031,6 +3031,7 @@ static void dasd_setup_queue(struct dasd max = block->base->discipline->max_blocks << block->s2b_shift; } queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue); + block->request_queue->limits.max_dev_sectors = max; blk_queue_logical_block_size(block->request_queue, block->bp_block); blk_queue_max_hw_sectors(block->request_queue, max); Patches currently in stable-queue which might be from sth@linux.vnet.ibm.com are queue-4.4/s390-dasd-fix-performance-drop.patch