Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755841Ab2E2WxI (ORCPT ); Tue, 29 May 2012 18:53:08 -0400 Received: from relay3.sgi.com ([192.48.152.1]:58134 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752176Ab2E2WxG (ORCPT ); Tue, 29 May 2012 18:53:06 -0400 Message-ID: <4FC55351.6020503@sgi.com> Date: Tue, 29 May 2012 15:53:05 -0700 From: Michael Reed User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Karandeep Chahal CC: "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "dillowda@ornl.gov" , "roland@kernel.org" , "sean.hefty@intel.com" Subject: Re: [PATCH 1/1] ib_srp: Infiniband srp fast failover patch. References: <4FC53AAA.3060203@ddn.com> <4FC544FE.3000204@sgi.com> <4FC54D62.3080003@ddn.com> In-Reply-To: <4FC54D62.3080003@ddn.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1933 Lines: 46 Thank you for clarifying! On 05/29/2012 03:27 PM, Karandeep Chahal wrote: > Hi Michael, > > Yes, I tried reconnecting the targets and removing reinserting ib-srp. > > Thanks > Karan > > > On 05/29/2012 05:51 PM, Michael Reed wrote: >> Did you subsequently reconnect the target and confirm appropriate behavior? >> >> >> On 05/29/2012 02:07 PM, Karandeep Chahal wrote: >>> Subject: [PATCH] Infiniband srp fast failover patch. Currently ib_srp does >>> not do anything on receiving a DREQ from the target, it >>> only sends a response back. Further it also does not >>> monitor port (down) events. I have patched srp to remove >>> scsi devices when a port down event is received or if the >>> target sends a DREQ. Currently even though the target >>> notifies the initiator of its intentions of going away, the >>> initiator ignores that information. Later the initiator >>> gets upset when the devices "suddenly" disappear resulting >>> in srp initiating an error recovery process which takes a >>> long time. This caused high failover latencies as compared >>> to fibre channel. In my experiments with RHEL 6.0 and 6.2 I >>> encountered failover time that exceeded 2 minutes and 20 >>> seconds (despite tweaking /etc/multipath.conf and >>> /sys/block/<>/timeout). With this patch the failover takes >>> 30 seconds. I have tested this patch with and without a >>> switch. >>> >>> Yours, etc. >>> Karan >>> > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/