From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753048AbdFVKAS (ORCPT ); Thu, 22 Jun 2017 06:00:18 -0400 Received: from prv3-mh.provo.novell.com ([137.65.250.26]:38785 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752719AbdFVKAR (ORCPT ); Thu, 22 Jun 2017 06:00:17 -0400 From: Yadan Fan To: don.brace@microsemi.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: esc.storagedev@microsemi.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, ydfan@suse.com Subject: [PATCH 1/2] hpsa: limit transfer length to 1MB Date: Thu, 22 Jun 2017 17:58:44 +0800 Message-Id: <20170622095845.4235-1-ydfan@suse.com> X-Mailer: git-send-email 2.12.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The hpsa firmware will bypass the cache for any request larger than 1MB, so we should cap the request size to avoid any performance degradation in SLE12-SP2. This degradation is caused from d2be537c3ba3568acd79cd178327b842e60d035e, which changed max_sectors_kb to 1280k, but the hardware is able to work fine with it, so the true fix should be from hpsa driver. References: bsc#1025461 Signed-off-by: Yadan Fan --- drivers/scsi/hpsa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 73daace478cb..b4c0bbea680c 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -952,7 +952,7 @@ static struct scsi_host_template hpsa_driver_template = { #endif .sdev_attrs = hpsa_sdev_attrs, .shost_attrs = hpsa_shost_attrs, - .max_sectors = 8192, + .max_sectors = 1024, .no_write_same = 1, }; -- 2.12.3