From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Riemer Subject: Re: [PATCH 05/14] IB/srp: Maintain a single connection per I_T nexus Date: Mon, 17 Jun 2013 11:41:59 +0200 Message-ID: <51BED9E7.5070304@profitbricks.com> References: <51B87501.4070005@acm.org> <51B876BF.4070400@acm.org> <51BA0655.6090707@mellanox.com> <51BA0E8F.3030104@acm.org> <51BA555F.9060807@mellanox.com> <51BAE482.1050304@profitbricks.com> <51BB4DBB.4070800@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51BB4DBB.4070800-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Vu Pham Cc: Bart Van Assche , Roland Dreier , David Dillow , linux-rdma List-Id: linux-rdma@vger.kernel.org On 14.06.2013 19:07, Vu Pham wrote: [...] >> For what do you need the same target with multiple pkeys on the same >> local SRP port? >> > There is no need, it's just a gray area that you can choose to have > multiple connections to same target using different pkeys (same as dgid) >> Which other SRP targets exist? >> > > Netapp/LSI/Engenio, DDN, TexasMemorySystem Ramsan (IBM), Nimbus, Violin > Memory, StreamScale > The last three may be derived from SCST base target. > >> I only know SCST, Solaris COMSTAR and that broken LIO stuff. >> Does SCST still not support to set the pkey? >> >> > Yes, I think so > >> Why should we check the dgid? >> >> > If you want to have multiple connections/qps to same target, but as I > said above, it's a gray area. > >> Doesn't make any sense to me to connect both target ports to the same >> local port. > What if a target always expose single consistent and unique SRP port > with tuple , the ioc_guid part is not derived from any > of its local HCA's GUID, then you can connect to this target thru > different HCA ports (different dgid) as different paths to same target. > Do you have an example for a target which does it like this or a use case where this makes sense? I guess you're proposing here to use a driver global list of target connections instead of handling this per local SRP port. This would result in bigger changes which I wouldn't do without a good reason. >> If you do so, the multipath-tools will crash. Note: This >> function is called per local SRP port. Perhaps, a note should be added >> to that function that it only has to be called per local SRP port. -- 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