From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Gurtovoy Subject: Re: ib-iser - 4k IO req size only Date: Sat, 8 Apr 2017 17:44:21 +0300 Message-ID: References: <704B9754-E679-41F3-80D7-0D783B53ADC8@googlemail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <704B9754-E679-41F3-80D7-0D783B53ADC8-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Heiner Lesaar , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org hi Heiner, On 4/8/2017 12:59 PM, Heiner Lesaar wrote: > Dear all, > > I use SCST 3.3.0 and ISCSI-SCST on CentOS7.3 (stock kernel) w. in-tree RDMA and Mellanox ConnectX-4 cards (no OFED packages) on the target. > > Same hardware / software on the initiator (w. open-iscsi and ib-iser, no OFED as well). > > When using iSer as the transport layer, all read and write requests from the connected initiator to the target devices are always exactly 4kb (checked w. e.g. "iostat -xm 2"), which harms the performance of large IO a lot obviously. > > Changing to TCP as the transport layer shows expected behaviour of larger IO requests (up to max_sector_size) and expected performance. > > Tested w. common everyday operations like "cp" or "dd", but also benchmark tools like "filebench". > I guess its something related to ib_iser, so I hope someone on the list has a good hint for me how to solve this. I sent a fix in 1e5db6c31ade41 commit. please apply it. Max. > > > Thank you very much for any kind help or response! > > > Heiner > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html