From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: Re: [PATCH v2 2/2] smartpqi: limit transfer length to 1MB Date: Fri, 23 Jun 2017 15:01:41 +0200 Message-ID: <20170623130141.GE13014@linux-x5ow.site> References: <20170623094006.16807-1-ydfan@suse.com> <20170623094006.16807-2-ydfan@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20170623094006.16807-2-ydfan@suse.com> Sender: linux-kernel-owner@vger.kernel.org To: Yadan Fan Cc: don.brace@microsemi.com, martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, esc.storagedev@microsemi.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On Fri, Jun 23, 2017 at 05:40:06PM +0800, Yadan Fan wrote: > The smartpqi firmware will bypass the cache for any request larger > than 1MB, so we should cap the request size to avoid any > performance degradation in kernels later than v4.3 > > 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 smartpqi driver. > > Signed-off-by: Yadan Fan > --- Reviewed-by: Johannes Thumshirn -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850