From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Gurtovoy Subject: Re: iSER initiator in 4.5 is unhappy.. Date: Thu, 7 Apr 2016 12:09:13 +0300 Message-ID: <570623B9.8040108@mellanox.com> References: <20160404134656.GA30269@infradead.org> <5702A46F.5070109@grimberg.me> <5702A6AC.9020008@grimberg.me> <20160404225831.GA6725@infradead.org> <57037D8E.4030506@grimberg.me> <20160405094339.GA1622@infradead.org> <570548AB.4090802@grimberg.me> <20160406231658.GB11588@infradead.org> <570608C9.1070805@grimberg.me> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <570608C9.1070805-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg , Christoph Hellwig Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 4/7/2016 10:14 AM, Sagi Grimberg wrote: > >>> So this scatterlist seems perfectly fine (no gaps). The only thing I >>> can think of is that we don't have enough space reserved, but I counted >>> 127 pages in the scatterlist when iser reserves 128 (by default). >>> >>> Just in case I mis-counted, can you (or Max) try with the below >>> patch: >> >> This works fine for me, but I wonder if the miscounting is in the >> block layer? > > We communicate the "max_pages" via sg_tablesize and max_hw_sectors. > > iSER communicates (or at least supposed to) sg_tablesize=128 and > max_sectors=1024 to scsi (which sets the block queues attributes), that > should be sufficient for handling all the incoming IO. Unless we didn't > account for the first-page offset and the reminder coming at the last > segment (which results in an extra page). The patch should fix the > problem, however in this particular sg list I don't see the violation > (counted 127 pages)... I counted 129 pages. I will run some tests in our labs too. Thanks. -- 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