From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH 8/8] IB/srp: Make queue size configurable Date: Fri, 13 Sep 2013 16:31:27 +0200 Message-ID: <523321BF.9020403@acm.org> References: <521363EA.8080906@acm.org> <52136609.3090406@acm.org> <1378782080.3794.6.camel@feather.ornl.gov> <522F5A81.8040101@acm.org> <1378937796.6649.5.camel@haswell.thedillows.org> <5231E8CE.5060105@gmail.com> <5231EC1A.7030902@acm.org> <5232C76B.4010704@gmail.com> <5232CF86.20507@acm.org> <5232D9BC.7090808@acm.org> <5233043F.5020804@gmail.com> <52331444.8070007@acm.org> <52331854.9010607@gmail.com> <52331B47.9070202@acm.org> <52331E01.3060005@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52331E01.3060005-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jack Wang Cc: David Dillow , David Dillow , Roland Dreier , Vu Pham , Sebastian Riemer , linux-rdma , Konrad Grzybowski List-Id: linux-rdma@vger.kernel.org On 09/13/13 16:15, Jack Wang wrote: > Hello Bart, > >> cat /sys/class/scsi_host/host36/req_lim >> 64 > > I just checked srp spec, which do define such behaviour, I wonder in > SCST/SRPT, how the request limit is chosen, is it report from low level > hardware driver? Hello Jack, The following code probably provides the information you are looking for: /* * Avoid QUEUE_FULL conditions by limiting the number of buffers used * for the SRP protocol to the SCST SCSI command queue size. */ ch->rq_size = min(SRPT_RQ_SIZE, scst_get_max_lun_commands(NULL, 0)); In other words, req_lim can be increased by increasing both SRPT_RQ_SIZE and SCST_MAX_DEV_COMMANDS. Bart. -- 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