From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: Testing for RDMA with ib_srp: Failed to map data (-12) with max_sectors_kb=4096 and buffered I/O with 4MB writes Date: Thu, 21 Apr 2016 21:15:01 +0300 Message-ID: <571918A5.8050504@grimberg.me> References: <559411025.30902774.1461207472544.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <559411025.30902774.1461207472544.JavaMail.zimbra-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Laurence Oberman , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org > Hello > > I am still on my quest for getting 4MB buffered writes to be stable to RDMA SRP targets. > Lots of testing has been performed here with EDR 100 back to back connections using > mellanox ConnectX-4 with mlx5_ib, an dthe ib_srp* drivers on target server and client. > > In summary: > setting max_sectors_kb=4096 and running DIRECT_IO is solid as a rock > setting max_sectors_kb=2048 and running buffered 4MB writes to an FS on a multipath is rock solid > > However: > setting max_sectors_kb=4096 and running buffered I/O sees serious mapping issues. > > > I have isolated the failure and call flow to this > > srp_queuecommand > srp_map_data(scmnd, ch, req); > srp_map_idb > ret = srp_map_finish_fr(&state, req, ch, 1); > > > The -12 is returned by srp_map_finish_fr() and fed back to fail with > ib_srp: Failed to map data (-12) Can you print out how many FRs we used at this point? state->nmdesc? -- 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