From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: [RFC ib_srp-backport] ib_srp: bind fast IO failing to QP timeout Date: Tue, 19 Mar 2013 13:22:07 +0200 Message-ID: <51484A5F.6040601@mellanox.com> References: <51483B19.1070201@profitbricks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51483B19.1070201-EIkl63zCoXaH+58JC4qpiA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sebastian Riemer Cc: Bart Van Assche , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Sagi Grimberg , Oren Duer List-Id: linux-rdma@vger.kernel.org On 19/03/2013 12:16, Sebastian Riemer wrote: > Hi Bart, > > now I've got my priority on SRP again. Hi Sebastian, Are these patches targeted to upstream or backports to some OS/kernel? if the former, can you please send them inline so we can have proper review? Or. > > I've also noticed that your ib_srp-backport doesn't fail the IO fast > enough. The fast_io_fail_tmo only comes into play after the QP is > already in timeout and the "terminate_rport_io" function is missing. > > My idea is to use the QP retry count directly for fast IO failing. It is > at 7 by default and the QP timeout is at approx. 2s. The overall QP > timeout is at approx. 35s already (1+7 tries * 2s * 2, I guess). Using > only 3 retries I'm at approx 18s. > > My patches introduce that parameter as module parameter as it is quite > difficult to set the QP from RTS to RTR again. Only there the QP timeout > parameters can be set. > > My patch series isn't complete yet as paths aren't reconnected - they > are only failed fast bound to the overall QP timeout. But it should give > you an idea what I'm trying to do here. > > What are your thought regarding this? > > Attached patches: > ib_srp: register srp_fail_rport_io as terminate_rport_io > ib_srp: be quiet when failing SCSI commands > scsi_transport_srp: disable the fast_io_fail_tmo parameter > ib_srp: show the QP timeout and retry count in srp_host sysfs files > ib_srp: introduce qp_retry_cnt module parameter > > Cheers, > Sebastian > > > Btw.: Before, I've hacked MD RAID-1 for high-performance replication as > DRBD is crap for our purposes. But that's worthless without a reliably > working transport. -- 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